{"id":1333,"date":"2019-07-26T21:08:24","date_gmt":"2019-07-27T01:08:24","guid":{"rendered":"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/chapter\/unit-7-body-structure\/"},"modified":"2024-12-02T13:43:41","modified_gmt":"2024-12-02T18:43:41","slug":"unit-7-body-structure","status":"publish","type":"chapter","link":"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/chapter\/unit-7-body-structure\/","title":{"raw":"Unit 7: Body Structure","rendered":"Unit 7: Body Structure"},"content":{"raw":"<div class=\"textbox shaded\">\r\n\r\n<strong>Unit Outline<\/strong>\r\n\r\n<a href=\"#7.1\"><strong>Part 1:<\/strong> Body Systems<\/a>\r\n\r\n<a href=\"#7.2\"><strong>Part 2:<\/strong> Anatomical Terminology<\/a>\r\n<ul>\r\n \t<li><a href=\"#7.2a\">The anatomical position<\/a><\/li>\r\n \t<li><a href=\"#7.2b\">Regional terms<\/a><\/li>\r\n \t<li><a href=\"#7.2c\">Directional terms<\/a><\/li>\r\n \t<li><a href=\"#7.2d\">Body planes<\/a><\/li>\r\n \t<li><a href=\"#7.2e\">Body cavities and serous membranes<\/a>\r\n<ul>\r\n \t<li>Subdivisions of the posterior and anterior cavities<\/li>\r\n \t<li>Abdominopelvic regions and quadrants<\/li>\r\n \t<li>Membranes of the anterior body cavity<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n<h2><a href=\"#p\">Practice Questions<\/a><\/h2>\r\n<\/div>\r\n<div class=\"textbox textbox--learning-objectives\"><header class=\"textbox__header\">\r\n<p class=\"textbox__title\"><strong>Learning Objectives<\/strong><\/p>\r\n\r\n<\/header>\r\n<div class=\"textbox__content\">\r\n\r\nAt the end of this unit, you should be able to:\r\n<p class=\"hanging-indent\"><strong>I.<\/strong> Define the terms organ, organ system and organism.<\/p>\r\n<p class=\"hanging-indent\"><strong>II. <\/strong>Name the eleven organ systems of the human body, identify the major organs, and give a major function of each system.<\/p>\r\n<p class=\"hanging-indent\"><strong>III. <\/strong>Define and demonstrate the anatomical position.<\/p>\r\n<p class=\"hanging-indent\"><strong>IV.<\/strong> Locate the anterior (ventral) and posterior (dorsal) surfaces for the body, hands and feet.<\/p>\r\n<p class=\"hanging-indent\"><strong>V.<\/strong> Define the directional terms used in human anatomy.<\/p>\r\n<p class=\"hanging-indent\"><strong>VI.<\/strong> Define sagittal, frontal, and transverse planes, and distinguish between midsagittal (median) and parasagittal planes.<\/p>\r\n<p class=\"hanging-indent\"><strong>VII.<\/strong> Specify and describe the limits of the body cavities.<\/p>\r\n<p class=\"hanging-indent\"><strong>VIII.<\/strong> Describe how the abdominopelvic region is divided into either nine regions or four quadrants.<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<div class=\"textbox textbox--learning-objectives\"><header class=\"textbox__header\">\r\n<p class=\"textbox__title\"><strong>Learning Objectives and Guiding Questions<\/strong><\/p>\r\n\r\n<\/header>\r\n<div class=\"textbox__content\">\r\n\r\nAt the end of this unit, you should be able to complete all the following tasks, including answering the guiding questions associated with each task.\r\n<p class=\"hanging-indent\"><strong>I.<\/strong> Define the terms organ, organ system and organism.<\/p>\r\n<p class=\"hanging-indent\"><strong>II. <\/strong>Name the eleven organ systems of the human body, identify the major organs, and give a major function of each system.<\/p>\r\n\r\n<ol>\r\n \t<li>Create a table specifying the eleven organ systems of the human body, the major organs found in each organ system, and at least one major function of each organ system.<\/li>\r\n<\/ol>\r\n<p class=\"hanging-indent\"><strong>III. <\/strong>Define and demonstrate the anatomical position.<\/p>\r\n\r\n<ol>\r\n \t<li>Sketch a human body in standard anatomical position.<\/li>\r\n \t<li>Use complete sentences to clearly describe the position of each of the following components of the human body when in standard anatomical position:\r\n<ul>\r\n \t<li>Feet<\/li>\r\n \t<li>Upper limbs<\/li>\r\n \t<li>Trunk<\/li>\r\n \t<li>Head<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ol>\r\n<p class=\"hanging-indent\"><strong>IV.<\/strong> Locate the anterior (ventral) and posterior (dorsal) surfaces of the human body, hands, and feet.<\/p>\r\n\r\n<ol>\r\n \t<li>Clearly define each of the following terms:\r\n<ul>\r\n \t<li>Anterior<\/li>\r\n \t<li>Posterior<\/li>\r\n \t<li>Ventral<\/li>\r\n \t<li>Dorsal<\/li>\r\n<\/ul>\r\n<\/li>\r\n \t<li>Explain why \u2018anterior\u2019 and \u2018ventral\u2019 can be used interchangeably to describe relative locations in the human body.<\/li>\r\n \t<li>Explain why \u2018posterior\u2019 and \u2018dorsal\u2019 can be used interchangeably to describe relative locations in the human body.<\/li>\r\n \t<li>Identify the direction (ventral or dorsal) in which the palms face when in standard anatomical position, and thus identify which side of the hand (palm or back) of the hand is the ventral side of the hand, and which is the dorsal side.<\/li>\r\n \t<li>Compare the anatomy of the foot to the anatomy of the hand to identify which side of the foot (sole or top) is the ventral side of the foot, and which is the dorsal side.<\/li>\r\n \t<li>Sketch each of the following, and on each diagram clearly indicate the anterior (ventral) and posterior (dorsal) surfaces:\r\n<ul>\r\n \t<li>A human body<\/li>\r\n \t<li>A human hand<\/li>\r\n \t<li>A human foot<\/li>\r\n<\/ul>\r\n<\/li>\r\n \t<li>Use complete sentences to describe how to identify the anterior (ventral) and posterior (dorsal) surfaces of each of the following:\r\n<ul>\r\n \t<li>The human body<\/li>\r\n \t<li>The human hand<\/li>\r\n \t<li>The human foot<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ol>\r\n<p class=\"hanging-indent\"><strong>V.<\/strong> Define the directional terms used in human anatomy.<\/p>\r\n\r\n<ol>\r\n \t<li>Define each of the following terms and provide one complete sentence that correctly uses each term to describe the relative position of two or three body structures (as appropriate).\r\n<ul>\r\n \t<li>Superior<\/li>\r\n \t<li>Inferior<\/li>\r\n \t<li>Medial<\/li>\r\n \t<li>Lateral<\/li>\r\n \t<li>Intermediate<\/li>\r\n \t<li>Peripheral<\/li>\r\n \t<li>Central<\/li>\r\n \t<li>Proximal<\/li>\r\n \t<li>Distal<\/li>\r\n \t<li>Deep<\/li>\r\n \t<li>Superficial<\/li>\r\n \t<li>Anterior<\/li>\r\n \t<li>Posterior<\/li>\r\n \t<li>Cranial<\/li>\r\n \t<li>Caudal<\/li>\r\n<\/ul>\r\n<\/li>\r\n \t<li>Distinguish between the terms prone and supine.<\/li>\r\n<\/ol>\r\n<p class=\"hanging-indent\"><strong>VI.<\/strong> Define sagittal, frontal, and transverse planes, and distinguish between midsagittal (median) and parasagittal planes.<\/p>\r\n\r\n<ol>\r\n \t<li>Explain why a body structure is often cut into thin sections before viewing.<\/li>\r\n \t<li>Define each of the following:\r\n<ul>\r\n \t<li>Sagittal plane<\/li>\r\n \t<li>Midsagittal (median) plane<\/li>\r\n \t<li>Parasagittal plane<\/li>\r\n \t<li>Frontal (coronal) plane<\/li>\r\n \t<li>Transverse plane<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ol>\r\n<p class=\"hanging-indent\"><strong>VII.<\/strong> Specify and describe the limits of the body cavities.<\/p>\r\n\r\n<ol>\r\n \t<li>Sketch a diagram of the human body showing the relative locations of all the following body cavities:\r\n<ul>\r\n \t<li>Dorsal body cavity<\/li>\r\n \t<li>Ventral body cavity<\/li>\r\n \t<li>Cranial cavity<\/li>\r\n \t<li>Vertebral cavity<\/li>\r\n \t<li>Thoracic cavity<\/li>\r\n \t<li>Abdominal cavity<\/li>\r\n \t<li>Pelvic cavity<\/li>\r\n \t<li>Abdominopelvic cavity<\/li>\r\n<\/ul>\r\n<\/li>\r\n \t<li>For each of the following cavities, specify whether there is a physical body structure separating them or not. If there is a major body structure separating them, name that structure.\r\n<ul>\r\n \t<li>Dorsal and ventral body cavities<\/li>\r\n \t<li>Cranial and vertebral cavities<\/li>\r\n \t<li>Thoracic and abdominal cavities<\/li>\r\n \t<li>Abdominal and pelvic cavities<\/li>\r\n \t<li>Abdominal and vertebral cavities<\/li>\r\n<\/ul>\r\n<\/li>\r\n \t<li>For each of the following cavities, name all the organs found within that cavity:\r\n<ul>\r\n \t<li>Cranial cavity<\/li>\r\n \t<li>Vertebral cavity<\/li>\r\n \t<li>Thoracic cavity<\/li>\r\n \t<li>Abdominal cavity<\/li>\r\n \t<li>Pelvic cavity<\/li>\r\n<\/ul>\r\n<\/li>\r\n \t<li>For each of the following cavities, name any organ systems that are (mostly) contained within that cavity:\r\n<ul>\r\n \t<li>Cranial cavity<\/li>\r\n \t<li>Vertebral cavity<\/li>\r\n \t<li>Thoracic cavity<\/li>\r\n \t<li>Abdominal cavity<\/li>\r\n \t<li>Pelvic cavity<\/li>\r\n<\/ul>\r\n<\/li>\r\n \t<li>Define each of the following terms, using only a single short sentence for each:\r\n<ul>\r\n \t<li>Parietal serosa<\/li>\r\n \t<li>Visceral serosa<\/li>\r\n \t<li>Serous fluid<\/li>\r\n \t<li>Parietal pericardium<\/li>\r\n \t<li>Visceral pericardium<\/li>\r\n \t<li>Parietal peritoneum<\/li>\r\n \t<li>Visceral peritoneum<\/li>\r\n \t<li>Parietal pleurae<em> (NB: \u201cpleurae\u201d means \u201cmore than one pleura\u201d<\/em><em>; why are there multiple pleurae<\/em><em>?)<\/em><\/li>\r\n \t<li>Visceral pleurae<\/li>\r\n<\/ul>\r\n<\/li>\r\n \t<li>Briefly describe the general function of serosa and the serous fluid in the human body.<\/li>\r\n<\/ol>\r\n<p class=\"hanging-indent\"><strong>VIII.<\/strong> Describe how the abdominopelvic region is divided into either nine regions or four quadrants.<\/p>\r\n\r\n<ol>\r\n \t<li>Specify the locations of each of the following nine abdominopelvic regions:\r\n<ul>\r\n \t<li>Right hypochondriac<\/li>\r\n \t<li>Epigastric<\/li>\r\n \t<li>Left hypochondriac<\/li>\r\n \t<li>Right lumbar<\/li>\r\n \t<li>Umbilical<\/li>\r\n \t<li>Left lumbar<\/li>\r\n \t<li>Right iliac<\/li>\r\n \t<li>Hypogastric<\/li>\r\n \t<li>Left iliac<\/li>\r\n<\/ul>\r\n<\/li>\r\n \t<li style=\"text-align: justify\">Describe the location of each of the following abdominopelvic quadrants:\r\n<ul>\r\n \t<li style=\"text-align: justify\">Right upper quadrant<\/li>\r\n \t<li style=\"text-align: justify\">Left upper quadrant<\/li>\r\n \t<li style=\"text-align: justify\">Right lower quadrant<\/li>\r\n \t<li>Left lower quadrant<\/li>\r\n<\/ul>\r\n<\/li>\r\n \t<li>Specify the location(s), within the nine abdominopelvic regions, of each of the following organs:\r\n<ul>\r\n \t<li style=\"text-align: justify\">Liver<\/li>\r\n \t<li style=\"text-align: justify\">Gall bladder<\/li>\r\n \t<li style=\"text-align: justify\">Spleen<\/li>\r\n \t<li style=\"text-align: justify\">Stomach<\/li>\r\n \t<li style=\"text-align: justify\">Small intestine<\/li>\r\n \t<li style=\"text-align: justify\">Caecum<\/li>\r\n \t<li style=\"text-align: justify\">Appendix<\/li>\r\n \t<li style=\"text-align: justify\">Ascending colon<\/li>\r\n \t<li style=\"text-align: justify\">Transverse colon<\/li>\r\n \t<li style=\"text-align: justify\">Descending colon<\/li>\r\n \t<li style=\"text-align: justify\">Urinary bladder<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ol>\r\n<\/div>\r\n<\/div>\r\n&nbsp;\r\n<h2 style=\"text-align: justify\"><strong><a id=\"7.1\"><\/a>Part 1: Body Systems<\/strong><\/h2>\r\n<p style=\"text-align: justify\">An <strong>organ<\/strong> is an anatomically distinct structure of the body composed of two or more tissue types. Each organ performs one or more specific physiological functions. An <strong>[pb_glossary id=\"2350\"]organ system[\/pb_glossary]<\/strong> is a group of organs that work together to perform major functions or meet physiological needs of the body.<\/p>\r\n<p style=\"text-align: justify\">The human body contains eleven distinct organ systems (Figure 1 and Figure 2). Assigning organs to organ systems can be imprecise since organs that \u201cbelong\u201d to one system can also have functions integral to another system. In fact, most organs contribute to more than one system.<\/p>\r\n<p style=\"text-align: justify\">The organism level is the highest level of anatomical organization. An <strong>[pb_glossary id=\"2351\"]organism[\/pb_glossary]<\/strong> is a living being that has a cellular structure and that can independently perform all physiologic functions necessary for life. In multicellular organisms, including humans, all cells, [pb_glossary id=\"2218\"]tissues[\/pb_glossary], [pb_glossary id=\"2217\"]organs[\/pb_glossary], and [pb_glossary id=\"2350\"]organ systems[\/pb_glossary] of the body work together to maintain the life and health of the [pb_glossary id=\"2351\"]organism[\/pb_glossary].<\/p>\r\n\r\n\r\n[caption id=\"\" align=\"alignnone\" width=\"633\"]<img src=\"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/image1-7.png\" alt=\"image\" width=\"633\" height=\"1046\" \/> <strong>Figure 1. Organ Systems of the Human Body.<\/strong> Organs that work together are grouped into organ systems.[\/caption]\r\n<h2 style=\"text-align: justify\"><strong><a id=\"7.2\"><\/a>Part 2: Anatomical Terminology<\/strong><\/h2>\r\n<p style=\"text-align: justify\">Anatomists and health care providers use terminology that can be bewildering to the uninitiated. However, the purpose of this language is not to confuse, but rather to increase precision and reduce medical errors. For example, is a scar \u201cabove the wrist\u201d located on the forearm two or three inches away from the hand? Or is it at the base of the hand? Is it on the palm-side or back-side? By using precise anatomical terminology, we eliminate ambiguity. Anatomical terms derive from Ancient Greek and Latin words. Because these languages are no longer used in everyday conversation, the meaning of their words does not change.<\/p>\r\n<p style=\"text-align: justify\">Anatomical terms are made up of roots, prefixes, and suffixes (Appendix II). The root of a term often refers to an organ, tissue, or condition, whereas the prefix or suffix often describes the root. For example, in the disorder hypertension, the prefix \u201chyper-\u201d means \u201chigh\u201d or \u201cover,\u201d and the root word \u201ctension\u201d refers to pressure, so the word \u201chypertension\u201d refers to abnormally high blood pressure.<\/p>\r\n\r\n\r\n[caption id=\"\" align=\"alignnone\" width=\"631\"]<img src=\"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/image2-7.png\" alt=\"image\" width=\"631\" height=\"1044\" \/> <strong>Figure 2. Organ Systems of the Human Body (continued).<\/strong> Organs that work together are grouped into organ systems.[\/caption]\r\n<h5 style=\"text-align: justify\"><strong><a id=\"7.2a\"><\/a>The anatomical position<\/strong><\/h5>\r\n<p style=\"text-align: justify\">To further increase precision, anatomists standardize the way in which they view the body. Just as maps are normally oriented with north at the top, the standard body \u201cmap,\u201d or anatomical position, is that of the body standing upright, with the feet parallel, at shoulder width apart and with toes forward. The upper limbs are held out to each side, and the palms of the hands face forward (Figure 3). Using this standard position reduces confusion. It does not matter how the body being described is oriented, the terms are used as if it is in anatomical position. For example, a scar in the \u201canterior (front) carpal (wrist) region\u201d would be present on the palm side of the wrist. The term \u201canterior\u201d would be used even if the hand were palm down on a table.<\/p>\r\n<p style=\"text-align: justify\">A body that is lying down is described as either prone or supine. <strong>[pb_glossary id=\"2355\"]Prone[\/pb_glossary]<\/strong> describes a face-down orientation, and <strong>[pb_glossary id=\"2356\"]supine[\/pb_glossary]<\/strong> describes a face up orientation. These terms are sometimes used in describing the position of the body during specific physical examinations or surgical procedures.<\/p>\r\n\r\n<h5 style=\"text-align: justify\"><strong><a id=\"7.2b\"><\/a>Regional Terms<\/strong><\/h5>\r\n<p style=\"text-align: justify\">The human body\u2019s numerous regions have specific terms to help increase precision (Figure 3). Notice that the term \u201cbrachium\u201d or \u201carm\u201d is reserved for the \u201cupper arm\u201d and \u201cantebrachium\u201d or \u201cforearm\u201d is used rather than \u201clower arm.\u201d Similarly, \u201cfemur\u201d or \u201cthigh\u201d is correct, and \u201cleg\u201d or \u201ccrus\u201d is reserved for the portion of the lower limb between the knee and the ankle. You will be able to describe the body\u2019s regions using the terms from the figure.<\/p>\r\n\r\n\r\n[caption id=\"\" align=\"alignnone\" width=\"1176\"]<img style=\"font-weight: bold;font-size: 14pt\" src=\"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/image3-7.png\" alt=\"image\" width=\"1176\" height=\"1031\" \/> <strong><strong>Figure 3. Regions of the Human Body.<\/strong> The human body is shown in anatomical position in an (a) anterior (ventral) view and a (b) posterior (dorsal) view. The regions of the body are labeled in boldface.<\/strong>[\/caption]\r\n\r\n&nbsp;\r\n<h5 class=\"unit-7:-body-structure:\"><strong><a id=\"7.2c\"><\/a>Directional Terms<\/strong><\/h5>\r\n<div class=\"unit-7:-body-structure:\">\r\n\r\nCertain directional anatomical terms appear throughout this and any other anatomy textbook (Figure 4). These terms are essential for describing the relative locations of different body structures. For instance, an anatomist might describe one band of tissue as \u201cinferior to\u201d another or a physician might describe a tumor as \u201csuperficial to\u201d a deeper body structure. Commit these terms to memory to avoid confusion when you are studying or describing the locations of particular body parts.\r\n<ul>\r\n \t<li style=\"text-align: justify\"><strong>[pb_glossary id=\"2357\"]Anterior[\/pb_glossary]<\/strong> (or ventral) describes the front or direction toward the front of the body. The toes are anterior\u00a0to the foot.<\/li>\r\n \t<li style=\"text-align: justify\"><strong>[pb_glossary id=\"2358\"]Posterior[\/pb_glossary]<\/strong> (or dorsal) describes the back or direction toward the back of the body. The [pb_glossary id=\"2407\"]popliteus[\/pb_glossary] is posterior to the [pb_glossary id=\"2408\"]patella[\/pb_glossary].<\/li>\r\n \t<li style=\"text-align: justify\"><strong>[pb_glossary id=\"2359\"]Superior[\/pb_glossary] <\/strong>(or <strong>cranial<\/strong>) describes a position above or higher than another part of the body proper. The orbits are superior to the [pb_glossary id=\"2406\"]oris[\/pb_glossary].<\/li>\r\n \t<li style=\"text-align: justify\">[pb_glossary id=\"2360\"]<strong>I<\/strong><strong>nferior<\/strong>[\/pb_glossary] (or <strong>caudal<\/strong>) describes a position below or lower than another part of the body proper; near or toward the tail (in humans, the [pb_glossary id=\"2409\"]coccyx[\/pb_glossary], or lowest part of the spinal column). The pelvis is inferior to the abdomen.<\/li>\r\n \t<li style=\"text-align: justify\"><strong>[pb_glossary id=\"2361\"]Lateral[\/pb_glossary] <\/strong>describes the side or direction toward the side of the body. The thumb ([pb_glossary id=\"2405\"]pollex[\/pb_glossary]) is lateral to the digits.<\/li>\r\n \t<li style=\"text-align: justify\"><strong>[pb_glossary id=\"2362\"]Medial[\/pb_glossary] <\/strong>describes the middle or direction toward the middle of the body. The [pb_glossary id=\"2404\"]hallux[\/pb_glossary] is the medial toe.<\/li>\r\n<\/ul>\r\n[caption id=\"\" align=\"alignnone\" width=\"977\"]<img src=\"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/image4-7.png\" alt=\"image\" width=\"977\" height=\"986\" \/> <strong>Figure 4. Directional Terms Applied to the Human Body.<\/strong> Paired directional terms are shown as applied to the human body.[\/caption]\r\n<ul>\r\n \t<li style=\"text-align: justify\"><strong>[pb_glossary id=\"2372\"]Intermediate[\/pb_glossary]<\/strong> describes a position between a more medial and a more lateral structure. The middle finger is intermediate between the ring and index fingers.<\/li>\r\n \t<li style=\"text-align: justify\"><strong>[pb_glossary id=\"2373\"]Proximal[\/pb_glossary] <\/strong>describes a position in a limb that is nearer to the point of attachment or the trunk of the body. The [pb_glossary id=\"2381\"]brachium[\/pb_glossary] is proximal to the [pb_glossary id=\"2382\"]antebrachium[\/pb_glossary].<\/li>\r\n \t<li style=\"text-align: justify\"><strong>[pb_glossary id=\"2374\"]Distal[\/pb_glossary] <\/strong>describes a position in a limb that is farther from the point of attachment or the trunk of the body. The crus is distal to the [pb_glossary id=\"2379\"]femur[\/pb_glossary].<\/li>\r\n \t<li style=\"text-align: justify\"><strong>[pb_glossary id=\"2375\"]Central[\/pb_glossary]<\/strong> describes a position towards the middle (centre) of a structure or organ system. The central nervous system is contained within the skull and vertebral column.<\/li>\r\n \t<li style=\"text-align: justify\"><strong>[pb_glossary id=\"2376\"]Peripheral[\/pb_glossary]<\/strong> describes a position towards the outer edge (periphery) of a structure or organ system. The peripheral nervous system is found outside the skull and vertebral column.<\/li>\r\n \t<li style=\"text-align: justify\"><strong>[pb_glossary id=\"2377\"]Superficial[\/pb_glossary]<\/strong> describes a position closer to the surface of the body. The skin is superficial to the bones.<\/li>\r\n \t<li style=\"text-align: justify\"><strong>[pb_glossary id=\"2378\"]Deep[\/pb_glossary] <\/strong>describes a position farther from the surface of the body. The brain is deep to the skull.<\/li>\r\n<\/ul>\r\n<h5 style=\"text-align: justify\"><strong><a id=\"7.2d\"><\/a>Body Planes<\/strong><\/h5>\r\n<p style=\"text-align: justify\">Sectioning, or cutting, is frequently used in the study of Anatomy. The body can be sectioned in various ways to produce a <strong>[pb_glossary id=\"2383\"]plane[\/pb_glossary]<\/strong>, this is a two-dimensional surface of a three-dimensional structure that has been cut. A body structure is often cut into thin sections before macroscopic viewing to allow visualization of the structure\u2019s interior and assist with identification of local disease or infiltration as these pathologies may not be obvious when observing the surface anatomy alone. Modern medical imaging devices enable clinicians to obtain \u201cvirtual sections\u201d of living bodies. We call these scans. Body sections and scans can be correctly interpreted, however, only if the viewer understands the plane along which the section was made. A plane is an imaginary two-dimensional surface that passes through the body. There are three planes commonly referred to in anatomy and medicine (Figure 5).<\/p>\r\n\r\n<ul>\r\n \t<li style=\"text-align: justify\">A <strong>[pb_glossary id=\"2384\"]sagittal plane[\/pb_glossary]<\/strong> is a plane that divides the body or an organ vertically into right and left sides. If this vertical plane runs directly down the middle of the body, it is called the <strong>[pb_glossary id=\"2386\"]midsagittal[\/pb_glossary]<\/strong> or <strong>median<\/strong> plane. If it divides the body into unequal right and left sides, it is called a [pb_glossary id=\"2385\"]<strong>parasagittal<\/strong> plane[\/pb_glossary] or (less commonly) a longitudinal section.<\/li>\r\n \t<li style=\"text-align: justify\">A <strong>[pb_glossary id=\"2387\"]frontal plane[\/pb_glossary]<\/strong> is a plane that divides the body or an organ into an anterior (front) portion and a posterior (rear) portion. A frontal plane is often referred to as a coronal plane (\"corona\u201d is Latin for \u201ccrown\u201d).<\/li>\r\n \t<li style=\"text-align: justify\">A <strong>[pb_glossary id=\"2388\"]transverse plane[\/pb_glossary]<\/strong> is a plane that divides the body or organ horizontally into upper and lower portions. Transverse planes produce images referred to as cross sections.<\/li>\r\n<\/ul>\r\n[caption id=\"\" align=\"alignnone\" width=\"618\"]<img src=\"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/image5-7.png\" alt=\"image\" width=\"618\" height=\"634\" \/> <strong>Figure 5. Planes of the Body.<\/strong> The three planes most commonly used in anatomical and medical imaging are the sagittal, frontal (or coronal), and transverse plane.[\/caption]\r\n\r\n<\/div>\r\n<div><\/div>\r\n<div class=\"unit-7:-body-structure:\">\r\n<h5><strong>Body Cavities and Serous Membranes<\/strong><\/h5>\r\nThe body maintains its internal organization by means of membranes, sheaths, and other structures that separate compartments. The [pb_glossary id=\"2389\"]dorsal (posterior) cavity[\/pb_glossary] and the [pb_glossary id=\"2390\"]ventral (anterior) cavity[\/pb_glossary] are the largest body compartments (Figure 6). These cavities contain and protect delicate internal organs, and the ventral cavity allows for significant changes in the size and shape of the organs as they perform their functions. The lungs, heart, stomach, and intestines, for example, can expand and contract without distorting other tissues or disrupting the activity of nearby organs.\r\n<p style=\"text-align: justify\"><strong>Subdivisions of the Posterior (Dorsal) and Anterior (Ventral) Cavities:\u00a0<\/strong>The posterior (dorsal) and anterior (ventral) cavities are each subdivided into smaller cavities. In the posterior (dorsal) cavity, the <strong>[pb_glossary id=\"2391\"]cranial cavity[\/pb_glossary]<\/strong> houses the brain, and the <strong>[pb_glossary id=\"2392\"]spinal cavity[\/pb_glossary]<\/strong> (or vertebral cavity) encloses the spinal cord. Just as the brain and spinal cord make up a continuous, uninterrupted structure, the cranial and spinal cavities that house them are also continuous. The brain and spinal cord are protected by the bones of the skull and vertebral column and by [pb_glossary id=\"2137\"]cerebrospinal fluid[\/pb_glossary], a colorless fluid produced by the brain, which cushions the brain and spinal cord within the posterior (dorsal) cavity.<\/p>\r\n<p style=\"text-align: justify\">The anterior (ventral) cavity has two main subdivisions: the thoracic cavity\u00a0and the abdominopelvic cavity (Figure 6). The <strong>[pb_glossary id=\"2393\"]thoracic cavity[\/pb_glossary]<\/strong> is the more superior subdivision of the anterior cavity, and it is enclosed by the rib cage. The thoracic cavity contains the lungs and the heart, which is located in the [pb_glossary id=\"2395\"]mediastinum[\/pb_glossary]. The diaphragm forms the floor of the thoracic cavity and separates it from the more inferior abdominopelvic cavity. The <strong>[pb_glossary id=\"2394\"]abdominopelvic cavity[\/pb_glossary]<\/strong> is the largest cavity in the body. Although no membrane physically divides the abdominopelvic cavity, it can be useful to distinguish between the abdominal cavity, the division that houses the digestive organs, and the pelvic cavity, the division that houses the organs of reproduction.<\/p>\r\n\r\n\r\n[caption id=\"\" align=\"alignnone\" width=\"1180\"]<img src=\"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/image6-7.png\" alt=\"image\" width=\"1180\" height=\"683\" \/> <strong>Figure 6. Dorsal and Ventral Body Cavities.<\/strong> The ventral cavity includes the thoracic and abdominopelvic cavities and their subdivisions. The dorsal cavity includes the cranial and spinal cavities.[\/caption]\r\n<p style=\"text-align: justify\"><strong>Abdominopelvic <\/strong><strong>Regions and Quadrants:<\/strong> To promote clear communication, for instance about the location of a patient\u2019s abdominal pain or a suspicious mass, health care providers typically divide up the [pb_glossary id=\"2394\"]abdominopelvic cavity[\/pb_glossary] into either nine regions or four quadrants (Figure 7).<\/p>\r\n\r\n\r\n[caption id=\"\" align=\"alignnone\" width=\"1210\"]<img src=\"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/image7-6.png\" alt=\"image\" width=\"1210\" height=\"625\" \/> <strong>Figure 7. Regions and Quadrants of the Abdominopelvic Cavity.<\/strong> There are (a) nine abdominopelvic regions and (b) four abdominopelvic quadrants in the peritoneal cavity.[\/caption]\r\n<p style=\"text-align: justify\">The more detailed regional approach subdivides the cavity with one horizontal line immediately inferior to the ribs and one immediately superior to the pelvis, and two vertical lines drawn as if dropped from the midpoint of each clavicle (collarbone). There are nine resulting regions. The simpler quadrants approach, which is also commonly used in medicine, subdivides the cavity with one horizontal and one vertical line that intersect at the patient\u2019s umbilicus (navel).<\/p>\r\n<p style=\"text-align: justify\">These regions can be used to identify the location of abdominal organs more precisely.\u00a0 For example:<\/p>\r\n\r\n<ul>\r\n \t<li>The right [pb_glossary id=\"2416\"]hypochondriac region[\/pb_glossary] contains the gall bladder and part of the liver, and the right kidney<\/li>\r\n \t<li>The [pb_glossary id=\"2417\"]epigastric region[\/pb_glossary] contains part of the liver and part of the stomach<\/li>\r\n \t<li>The left hypochondriac region contains part of the spleen and part of the stomach, and the left kidney<\/li>\r\n \t<li>The right [pb_glossary id=\"2419\"]lumbar region[\/pb_glossary] contains most of the ascending [pb_glossary id=\"2423\"]colon[\/pb_glossary]<\/li>\r\n \t<li>The [pb_glossary id=\"2420\"]umbilical region[\/pb_glossary] contains the transverse colon and part of the small intestine<\/li>\r\n \t<li>The left lumbar region contains most of the descending colon<\/li>\r\n \t<li>The right [pb_glossary id=\"2421\"]iliac region[\/pb_glossary] contains the appendix and [pb_glossary id=\"2424\"]caecum[\/pb_glossary]<\/li>\r\n \t<li>The [pb_glossary id=\"2422\"]hypogastric region[\/pb_glossary] contains the lower small intestine, the distal sigmoid colon and anus, and the urinary bladder, as well as the uterus and ovaries in females and the prostate in males<\/li>\r\n \t<li>The left iliac region contains the proximal sigmoid colon<\/li>\r\n<\/ul>\r\n<p style=\"text-align: justify\"><strong>Membranes of the Anterior (Ventral) Body Cavity:<\/strong> A <strong>[pb_glossary id=\"2425\"]serous membrane[\/pb_glossary]<\/strong> (also referred to as a serosa) is one of the thin membranes that cover the walls and organs in the [pb_glossary id=\"2393\"]thoracic[\/pb_glossary] and [pb_glossary id=\"2394\"]abdominopelvic[\/pb_glossary] cavities. The [pb_glossary id=\"2426\"]parietal[\/pb_glossary] layers of the membranes line the walls of the body cavity (pariet- refers to a cavity wall). The [pb_glossary id=\"2427\"]visceral[\/pb_glossary] layer of the membrane covers the organs (the viscera). Between the parietal and visceral layers is a very thin, fluid-filled serous space, or cavity (Figure 8).<\/p>\r\n<p style=\"text-align: justify\">There are three serous cavities and their associated membranes. The <strong>[pb_glossary id=\"2428\"]pleura[\/pb_glossary]<\/strong> is the serous membrane that surrounds the lungs in the pleural cavity; the <strong>[pb_glossary id=\"2140\"]pericardium[\/pb_glossary]<\/strong> is the serous membrane that surrounds the heart in the pericardial cavity; and the <strong>[pb_glossary id=\"2429\"]peritoneum[\/pb_glossary]<\/strong> is the serous membrane that surrounds several organs in the abdominopelvic cavity.<\/p>\r\n\r\n\r\n[caption id=\"\" align=\"alignnone\" width=\"865\"]<img src=\"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/image8-6.png\" alt=\"image\" width=\"865\" height=\"431\" \/> <strong>Figure 8. Serous Membrane.<\/strong> Serous membrane lines the pericardial cavity and reflects back to cover the heart\u2014much the same way that an underinflated balloon would form two layers surrounding a fist.[\/caption]\r\n<p style=\"text-align: justify\">The serous membranes form fluid-filled sacs, or cavities, that cushion and reduce friction on internal organs when they move, such as when the lungs inflate or the heart beats. Both the parietal and visceral serosa secrete the thin, slippery serous fluid located within the serous cavities.<\/p>\r\n<p style=\"text-align: justify\">The pleural cavity reduces friction between the lungs and the body wall. Likewise, the pericardial cavity reduces friction between the heart and the wall of the pericardium. The peritoneal cavity reduces friction between the abdominal and pelvic organs and the body wall. Therefore, serous membranes provide additional protection to the viscera they enclose by reducing friction that could lead to inflammation of the organs.<\/p>\r\n\r\n<\/div>\r\n<div class=\"textbox textbox--exercises\"><header class=\"textbox__header\">\r\n<p class=\"textbox__title\"><a id=\"p\"><\/a>Practice Questions<\/p>\r\n\r\n<\/header>\r\n<div class=\"textbox__content\">\r\n\r\n<strong>Part 1:<\/strong> Body Systems\r\n\r\n[h5p id=\"157\"]\r\n\r\n<strong>Part 2:<\/strong> Anatomical Terminology\r\n\r\n[h5p id=\"158\"]\r\n\r\n[h5p id=\"159\"]\r\n\r\n[h5p id=\"160\"]\r\n\r\n<\/div>\r\n<\/div>\r\n&nbsp;","rendered":"<div class=\"textbox shaded\">\n<p><strong>Unit Outline<\/strong><\/p>\n<p><a href=\"#7.1\"><strong>Part 1:<\/strong> Body Systems<\/a><\/p>\n<p><a href=\"#7.2\"><strong>Part 2:<\/strong> Anatomical Terminology<\/a><\/p>\n<ul>\n<li><a href=\"#7.2a\">The anatomical position<\/a><\/li>\n<li><a href=\"#7.2b\">Regional terms<\/a><\/li>\n<li><a href=\"#7.2c\">Directional terms<\/a><\/li>\n<li><a href=\"#7.2d\">Body planes<\/a><\/li>\n<li><a href=\"#7.2e\">Body cavities and serous membranes<\/a>\n<ul>\n<li>Subdivisions of the posterior and anterior cavities<\/li>\n<li>Abdominopelvic regions and quadrants<\/li>\n<li>Membranes of the anterior body cavity<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h2><a href=\"#p\">Practice Questions<\/a><\/h2>\n<\/div>\n<div class=\"textbox textbox--learning-objectives\">\n<header class=\"textbox__header\">\n<p class=\"textbox__title\"><strong>Learning Objectives<\/strong><\/p>\n<\/header>\n<div class=\"textbox__content\">\n<p>At the end of this unit, you should be able to:<\/p>\n<p class=\"hanging-indent\"><strong>I.<\/strong> Define the terms organ, organ system and organism.<\/p>\n<p class=\"hanging-indent\"><strong>II. <\/strong>Name the eleven organ systems of the human body, identify the major organs, and give a major function of each system.<\/p>\n<p class=\"hanging-indent\"><strong>III. <\/strong>Define and demonstrate the anatomical position.<\/p>\n<p class=\"hanging-indent\"><strong>IV.<\/strong> Locate the anterior (ventral) and posterior (dorsal) surfaces for the body, hands and feet.<\/p>\n<p class=\"hanging-indent\"><strong>V.<\/strong> Define the directional terms used in human anatomy.<\/p>\n<p class=\"hanging-indent\"><strong>VI.<\/strong> Define sagittal, frontal, and transverse planes, and distinguish between midsagittal (median) and parasagittal planes.<\/p>\n<p class=\"hanging-indent\"><strong>VII.<\/strong> Specify and describe the limits of the body cavities.<\/p>\n<p class=\"hanging-indent\"><strong>VIII.<\/strong> Describe how the abdominopelvic region is divided into either nine regions or four quadrants.<\/p>\n<\/div>\n<\/div>\n<div class=\"textbox textbox--learning-objectives\">\n<header class=\"textbox__header\">\n<p class=\"textbox__title\"><strong>Learning Objectives and Guiding Questions<\/strong><\/p>\n<\/header>\n<div class=\"textbox__content\">\n<p>At the end of this unit, you should be able to complete all the following tasks, including answering the guiding questions associated with each task.<\/p>\n<p class=\"hanging-indent\"><strong>I.<\/strong> Define the terms organ, organ system and organism.<\/p>\n<p class=\"hanging-indent\"><strong>II. <\/strong>Name the eleven organ systems of the human body, identify the major organs, and give a major function of each system.<\/p>\n<ol>\n<li>Create a table specifying the eleven organ systems of the human body, the major organs found in each organ system, and at least one major function of each organ system.<\/li>\n<\/ol>\n<p class=\"hanging-indent\"><strong>III. <\/strong>Define and demonstrate the anatomical position.<\/p>\n<ol>\n<li>Sketch a human body in standard anatomical position.<\/li>\n<li>Use complete sentences to clearly describe the position of each of the following components of the human body when in standard anatomical position:\n<ul>\n<li>Feet<\/li>\n<li>Upper limbs<\/li>\n<li>Trunk<\/li>\n<li>Head<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n<p class=\"hanging-indent\"><strong>IV.<\/strong> Locate the anterior (ventral) and posterior (dorsal) surfaces of the human body, hands, and feet.<\/p>\n<ol>\n<li>Clearly define each of the following terms:\n<ul>\n<li>Anterior<\/li>\n<li>Posterior<\/li>\n<li>Ventral<\/li>\n<li>Dorsal<\/li>\n<\/ul>\n<\/li>\n<li>Explain why \u2018anterior\u2019 and \u2018ventral\u2019 can be used interchangeably to describe relative locations in the human body.<\/li>\n<li>Explain why \u2018posterior\u2019 and \u2018dorsal\u2019 can be used interchangeably to describe relative locations in the human body.<\/li>\n<li>Identify the direction (ventral or dorsal) in which the palms face when in standard anatomical position, and thus identify which side of the hand (palm or back) of the hand is the ventral side of the hand, and which is the dorsal side.<\/li>\n<li>Compare the anatomy of the foot to the anatomy of the hand to identify which side of the foot (sole or top) is the ventral side of the foot, and which is the dorsal side.<\/li>\n<li>Sketch each of the following, and on each diagram clearly indicate the anterior (ventral) and posterior (dorsal) surfaces:\n<ul>\n<li>A human body<\/li>\n<li>A human hand<\/li>\n<li>A human foot<\/li>\n<\/ul>\n<\/li>\n<li>Use complete sentences to describe how to identify the anterior (ventral) and posterior (dorsal) surfaces of each of the following:\n<ul>\n<li>The human body<\/li>\n<li>The human hand<\/li>\n<li>The human foot<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n<p class=\"hanging-indent\"><strong>V.<\/strong> Define the directional terms used in human anatomy.<\/p>\n<ol>\n<li>Define each of the following terms and provide one complete sentence that correctly uses each term to describe the relative position of two or three body structures (as appropriate).\n<ul>\n<li>Superior<\/li>\n<li>Inferior<\/li>\n<li>Medial<\/li>\n<li>Lateral<\/li>\n<li>Intermediate<\/li>\n<li>Peripheral<\/li>\n<li>Central<\/li>\n<li>Proximal<\/li>\n<li>Distal<\/li>\n<li>Deep<\/li>\n<li>Superficial<\/li>\n<li>Anterior<\/li>\n<li>Posterior<\/li>\n<li>Cranial<\/li>\n<li>Caudal<\/li>\n<\/ul>\n<\/li>\n<li>Distinguish between the terms prone and supine.<\/li>\n<\/ol>\n<p class=\"hanging-indent\"><strong>VI.<\/strong> Define sagittal, frontal, and transverse planes, and distinguish between midsagittal (median) and parasagittal planes.<\/p>\n<ol>\n<li>Explain why a body structure is often cut into thin sections before viewing.<\/li>\n<li>Define each of the following:\n<ul>\n<li>Sagittal plane<\/li>\n<li>Midsagittal (median) plane<\/li>\n<li>Parasagittal plane<\/li>\n<li>Frontal (coronal) plane<\/li>\n<li>Transverse plane<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n<p class=\"hanging-indent\"><strong>VII.<\/strong> Specify and describe the limits of the body cavities.<\/p>\n<ol>\n<li>Sketch a diagram of the human body showing the relative locations of all the following body cavities:\n<ul>\n<li>Dorsal body cavity<\/li>\n<li>Ventral body cavity<\/li>\n<li>Cranial cavity<\/li>\n<li>Vertebral cavity<\/li>\n<li>Thoracic cavity<\/li>\n<li>Abdominal cavity<\/li>\n<li>Pelvic cavity<\/li>\n<li>Abdominopelvic cavity<\/li>\n<\/ul>\n<\/li>\n<li>For each of the following cavities, specify whether there is a physical body structure separating them or not. If there is a major body structure separating them, name that structure.\n<ul>\n<li>Dorsal and ventral body cavities<\/li>\n<li>Cranial and vertebral cavities<\/li>\n<li>Thoracic and abdominal cavities<\/li>\n<li>Abdominal and pelvic cavities<\/li>\n<li>Abdominal and vertebral cavities<\/li>\n<\/ul>\n<\/li>\n<li>For each of the following cavities, name all the organs found within that cavity:\n<ul>\n<li>Cranial cavity<\/li>\n<li>Vertebral cavity<\/li>\n<li>Thoracic cavity<\/li>\n<li>Abdominal cavity<\/li>\n<li>Pelvic cavity<\/li>\n<\/ul>\n<\/li>\n<li>For each of the following cavities, name any organ systems that are (mostly) contained within that cavity:\n<ul>\n<li>Cranial cavity<\/li>\n<li>Vertebral cavity<\/li>\n<li>Thoracic cavity<\/li>\n<li>Abdominal cavity<\/li>\n<li>Pelvic cavity<\/li>\n<\/ul>\n<\/li>\n<li>Define each of the following terms, using only a single short sentence for each:\n<ul>\n<li>Parietal serosa<\/li>\n<li>Visceral serosa<\/li>\n<li>Serous fluid<\/li>\n<li>Parietal pericardium<\/li>\n<li>Visceral pericardium<\/li>\n<li>Parietal peritoneum<\/li>\n<li>Visceral peritoneum<\/li>\n<li>Parietal pleurae<em> (NB: \u201cpleurae\u201d means \u201cmore than one pleura\u201d<\/em><em>; why are there multiple pleurae<\/em><em>?)<\/em><\/li>\n<li>Visceral pleurae<\/li>\n<\/ul>\n<\/li>\n<li>Briefly describe the general function of serosa and the serous fluid in the human body.<\/li>\n<\/ol>\n<p class=\"hanging-indent\"><strong>VIII.<\/strong> Describe how the abdominopelvic region is divided into either nine regions or four quadrants.<\/p>\n<ol>\n<li>Specify the locations of each of the following nine abdominopelvic regions:\n<ul>\n<li>Right hypochondriac<\/li>\n<li>Epigastric<\/li>\n<li>Left hypochondriac<\/li>\n<li>Right lumbar<\/li>\n<li>Umbilical<\/li>\n<li>Left lumbar<\/li>\n<li>Right iliac<\/li>\n<li>Hypogastric<\/li>\n<li>Left iliac<\/li>\n<\/ul>\n<\/li>\n<li style=\"text-align: justify\">Describe the location of each of the following abdominopelvic quadrants:\n<ul>\n<li style=\"text-align: justify\">Right upper quadrant<\/li>\n<li style=\"text-align: justify\">Left upper quadrant<\/li>\n<li style=\"text-align: justify\">Right lower quadrant<\/li>\n<li>Left lower quadrant<\/li>\n<\/ul>\n<\/li>\n<li>Specify the location(s), within the nine abdominopelvic regions, of each of the following organs:\n<ul>\n<li style=\"text-align: justify\">Liver<\/li>\n<li style=\"text-align: justify\">Gall bladder<\/li>\n<li style=\"text-align: justify\">Spleen<\/li>\n<li style=\"text-align: justify\">Stomach<\/li>\n<li style=\"text-align: justify\">Small intestine<\/li>\n<li style=\"text-align: justify\">Caecum<\/li>\n<li style=\"text-align: justify\">Appendix<\/li>\n<li style=\"text-align: justify\">Ascending colon<\/li>\n<li style=\"text-align: justify\">Transverse colon<\/li>\n<li style=\"text-align: justify\">Descending colon<\/li>\n<li style=\"text-align: justify\">Urinary bladder<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n<\/div>\n<\/div>\n<p>&nbsp;<\/p>\n<h2 style=\"text-align: justify\"><strong><a id=\"7.1\"><\/a>Part 1: Body Systems<\/strong><\/h2>\n<p style=\"text-align: justify\">An <strong>organ<\/strong> is an anatomically distinct structure of the body composed of two or more tissue types. Each organ performs one or more specific physiological functions. An <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2350\">organ system<\/a><\/strong> is a group of organs that work together to perform major functions or meet physiological needs of the body.<\/p>\n<p style=\"text-align: justify\">The human body contains eleven distinct organ systems (Figure 1 and Figure 2). Assigning organs to organ systems can be imprecise since organs that \u201cbelong\u201d to one system can also have functions integral to another system. In fact, most organs contribute to more than one system.<\/p>\n<p style=\"text-align: justify\">The organism level is the highest level of anatomical organization. An <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2351\">organism<\/a><\/strong> is a living being that has a cellular structure and that can independently perform all physiologic functions necessary for life. In multicellular organisms, including humans, all cells, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2218\">tissues<\/a>, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2217\">organs<\/a>, and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2350\">organ systems<\/a> of the body work together to maintain the life and health of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2351\">organism<\/a>.<\/p>\n<figure style=\"width: 633px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/image1-7.png\" alt=\"image\" width=\"633\" height=\"1046\" \/><figcaption class=\"wp-caption-text\"><strong>Figure 1. Organ Systems of the Human Body.<\/strong> Organs that work together are grouped into organ systems.<\/figcaption><\/figure>\n<h2 style=\"text-align: justify\"><strong><a id=\"7.2\"><\/a>Part 2: Anatomical Terminology<\/strong><\/h2>\n<p style=\"text-align: justify\">Anatomists and health care providers use terminology that can be bewildering to the uninitiated. However, the purpose of this language is not to confuse, but rather to increase precision and reduce medical errors. For example, is a scar \u201cabove the wrist\u201d located on the forearm two or three inches away from the hand? Or is it at the base of the hand? Is it on the palm-side or back-side? By using precise anatomical terminology, we eliminate ambiguity. Anatomical terms derive from Ancient Greek and Latin words. Because these languages are no longer used in everyday conversation, the meaning of their words does not change.<\/p>\n<p style=\"text-align: justify\">Anatomical terms are made up of roots, prefixes, and suffixes (Appendix II). The root of a term often refers to an organ, tissue, or condition, whereas the prefix or suffix often describes the root. For example, in the disorder hypertension, the prefix \u201chyper-\u201d means \u201chigh\u201d or \u201cover,\u201d and the root word \u201ctension\u201d refers to pressure, so the word \u201chypertension\u201d refers to abnormally high blood pressure.<\/p>\n<figure style=\"width: 631px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/image2-7.png\" alt=\"image\" width=\"631\" height=\"1044\" \/><figcaption class=\"wp-caption-text\"><strong>Figure 2. Organ Systems of the Human Body (continued).<\/strong> Organs that work together are grouped into organ systems.<\/figcaption><\/figure>\n<h5 style=\"text-align: justify\"><strong><a id=\"7.2a\"><\/a>The anatomical position<\/strong><\/h5>\n<p style=\"text-align: justify\">To further increase precision, anatomists standardize the way in which they view the body. Just as maps are normally oriented with north at the top, the standard body \u201cmap,\u201d or anatomical position, is that of the body standing upright, with the feet parallel, at shoulder width apart and with toes forward. The upper limbs are held out to each side, and the palms of the hands face forward (Figure 3). Using this standard position reduces confusion. It does not matter how the body being described is oriented, the terms are used as if it is in anatomical position. For example, a scar in the \u201canterior (front) carpal (wrist) region\u201d would be present on the palm side of the wrist. The term \u201canterior\u201d would be used even if the hand were palm down on a table.<\/p>\n<p style=\"text-align: justify\">A body that is lying down is described as either prone or supine. <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2355\">Prone<\/a><\/strong> describes a face-down orientation, and <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2356\">supine<\/a><\/strong> describes a face up orientation. These terms are sometimes used in describing the position of the body during specific physical examinations or surgical procedures.<\/p>\n<h5 style=\"text-align: justify\"><strong><a id=\"7.2b\"><\/a>Regional Terms<\/strong><\/h5>\n<p style=\"text-align: justify\">The human body\u2019s numerous regions have specific terms to help increase precision (Figure 3). Notice that the term \u201cbrachium\u201d or \u201carm\u201d is reserved for the \u201cupper arm\u201d and \u201cantebrachium\u201d or \u201cforearm\u201d is used rather than \u201clower arm.\u201d Similarly, \u201cfemur\u201d or \u201cthigh\u201d is correct, and \u201cleg\u201d or \u201ccrus\u201d is reserved for the portion of the lower limb between the knee and the ankle. You will be able to describe the body\u2019s regions using the terms from the figure.<\/p>\n<figure style=\"width: 1176px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" style=\"font-weight: bold;font-size: 14pt\" src=\"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/image3-7.png\" alt=\"image\" width=\"1176\" height=\"1031\" \/><figcaption class=\"wp-caption-text\"><strong><strong>Figure 3. Regions of the Human Body.<\/strong> The human body is shown in anatomical position in an (a) anterior (ventral) view and a (b) posterior (dorsal) view. The regions of the body are labeled in boldface.<\/strong><\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<h5 class=\"unit-7:-body-structure:\"><strong><a id=\"7.2c\"><\/a>Directional Terms<\/strong><\/h5>\n<div class=\"unit-7:-body-structure:\">\n<p>Certain directional anatomical terms appear throughout this and any other anatomy textbook (Figure 4). These terms are essential for describing the relative locations of different body structures. For instance, an anatomist might describe one band of tissue as \u201cinferior to\u201d another or a physician might describe a tumor as \u201csuperficial to\u201d a deeper body structure. Commit these terms to memory to avoid confusion when you are studying or describing the locations of particular body parts.<\/p>\n<ul>\n<li style=\"text-align: justify\"><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2357\">Anterior<\/a><\/strong> (or ventral) describes the front or direction toward the front of the body. The toes are anterior\u00a0to the foot.<\/li>\n<li style=\"text-align: justify\"><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2358\">Posterior<\/a><\/strong> (or dorsal) describes the back or direction toward the back of the body. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2407\">popliteus<\/a> is posterior to the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2408\">patella<\/a>.<\/li>\n<li style=\"text-align: justify\"><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2359\">Superior<\/a> <\/strong>(or <strong>cranial<\/strong>) describes a position above or higher than another part of the body proper. The orbits are superior to the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2406\">oris<\/a>.<\/li>\n<li style=\"text-align: justify\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2360\"><strong>I<\/strong><strong>nferior<\/strong><\/a> (or <strong>caudal<\/strong>) describes a position below or lower than another part of the body proper; near or toward the tail (in humans, the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2409\">coccyx<\/a>, or lowest part of the spinal column). The pelvis is inferior to the abdomen.<\/li>\n<li style=\"text-align: justify\"><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2361\">Lateral<\/a> <\/strong>describes the side or direction toward the side of the body. The thumb (<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2405\">pollex<\/a>) is lateral to the digits.<\/li>\n<li style=\"text-align: justify\"><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2362\">Medial<\/a> <\/strong>describes the middle or direction toward the middle of the body. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2404\">hallux<\/a> is the medial toe.<\/li>\n<\/ul>\n<figure style=\"width: 977px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/image4-7.png\" alt=\"image\" width=\"977\" height=\"986\" \/><figcaption class=\"wp-caption-text\"><strong>Figure 4. Directional Terms Applied to the Human Body.<\/strong> Paired directional terms are shown as applied to the human body.<\/figcaption><\/figure>\n<ul>\n<li style=\"text-align: justify\"><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2372\">Intermediate<\/a><\/strong> describes a position between a more medial and a more lateral structure. The middle finger is intermediate between the ring and index fingers.<\/li>\n<li style=\"text-align: justify\"><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2373\">Proximal<\/a> <\/strong>describes a position in a limb that is nearer to the point of attachment or the trunk of the body. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2381\">brachium<\/a> is proximal to the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2382\">antebrachium<\/a>.<\/li>\n<li style=\"text-align: justify\"><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2374\">Distal<\/a> <\/strong>describes a position in a limb that is farther from the point of attachment or the trunk of the body. The crus is distal to the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2379\">femur<\/a>.<\/li>\n<li style=\"text-align: justify\"><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2375\">Central<\/a><\/strong> describes a position towards the middle (centre) of a structure or organ system. The central nervous system is contained within the skull and vertebral column.<\/li>\n<li style=\"text-align: justify\"><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2376\">Peripheral<\/a><\/strong> describes a position towards the outer edge (periphery) of a structure or organ system. The peripheral nervous system is found outside the skull and vertebral column.<\/li>\n<li style=\"text-align: justify\"><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2377\">Superficial<\/a><\/strong> describes a position closer to the surface of the body. The skin is superficial to the bones.<\/li>\n<li style=\"text-align: justify\"><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2378\">Deep<\/a> <\/strong>describes a position farther from the surface of the body. The brain is deep to the skull.<\/li>\n<\/ul>\n<h5 style=\"text-align: justify\"><strong><a id=\"7.2d\"><\/a>Body Planes<\/strong><\/h5>\n<p style=\"text-align: justify\">Sectioning, or cutting, is frequently used in the study of Anatomy. The body can be sectioned in various ways to produce a <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2383\">plane<\/a><\/strong>, this is a two-dimensional surface of a three-dimensional structure that has been cut. A body structure is often cut into thin sections before macroscopic viewing to allow visualization of the structure\u2019s interior and assist with identification of local disease or infiltration as these pathologies may not be obvious when observing the surface anatomy alone. Modern medical imaging devices enable clinicians to obtain \u201cvirtual sections\u201d of living bodies. We call these scans. Body sections and scans can be correctly interpreted, however, only if the viewer understands the plane along which the section was made. A plane is an imaginary two-dimensional surface that passes through the body. There are three planes commonly referred to in anatomy and medicine (Figure 5).<\/p>\n<ul>\n<li style=\"text-align: justify\">A <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2384\">sagittal plane<\/a><\/strong> is a plane that divides the body or an organ vertically into right and left sides. If this vertical plane runs directly down the middle of the body, it is called the <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2386\">midsagittal<\/a><\/strong> or <strong>median<\/strong> plane. If it divides the body into unequal right and left sides, it is called a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2385\"><strong>parasagittal<\/strong> plane<\/a> or (less commonly) a longitudinal section.<\/li>\n<li style=\"text-align: justify\">A <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2387\">frontal plane<\/a><\/strong> is a plane that divides the body or an organ into an anterior (front) portion and a posterior (rear) portion. A frontal plane is often referred to as a coronal plane (&#8220;corona\u201d is Latin for \u201ccrown\u201d).<\/li>\n<li style=\"text-align: justify\">A <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2388\">transverse plane<\/a><\/strong> is a plane that divides the body or organ horizontally into upper and lower portions. Transverse planes produce images referred to as cross sections.<\/li>\n<\/ul>\n<figure style=\"width: 618px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/image5-7.png\" alt=\"image\" width=\"618\" height=\"634\" \/><figcaption class=\"wp-caption-text\"><strong>Figure 5. Planes of the Body.<\/strong> The three planes most commonly used in anatomical and medical imaging are the sagittal, frontal (or coronal), and transverse plane.<\/figcaption><\/figure>\n<\/div>\n<div><\/div>\n<div class=\"unit-7:-body-structure:\">\n<h5><strong>Body Cavities and Serous Membranes<\/strong><\/h5>\n<p>The body maintains its internal organization by means of membranes, sheaths, and other structures that separate compartments. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2389\">dorsal (posterior) cavity<\/a> and the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2390\">ventral (anterior) cavity<\/a> are the largest body compartments (Figure 6). These cavities contain and protect delicate internal organs, and the ventral cavity allows for significant changes in the size and shape of the organs as they perform their functions. The lungs, heart, stomach, and intestines, for example, can expand and contract without distorting other tissues or disrupting the activity of nearby organs.<\/p>\n<p style=\"text-align: justify\"><strong>Subdivisions of the Posterior (Dorsal) and Anterior (Ventral) Cavities:\u00a0<\/strong>The posterior (dorsal) and anterior (ventral) cavities are each subdivided into smaller cavities. In the posterior (dorsal) cavity, the <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2391\">cranial cavity<\/a><\/strong> houses the brain, and the <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2392\">spinal cavity<\/a><\/strong> (or vertebral cavity) encloses the spinal cord. Just as the brain and spinal cord make up a continuous, uninterrupted structure, the cranial and spinal cavities that house them are also continuous. The brain and spinal cord are protected by the bones of the skull and vertebral column and by <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2137\">cerebrospinal fluid<\/a>, a colorless fluid produced by the brain, which cushions the brain and spinal cord within the posterior (dorsal) cavity.<\/p>\n<p style=\"text-align: justify\">The anterior (ventral) cavity has two main subdivisions: the thoracic cavity\u00a0and the abdominopelvic cavity (Figure 6). The <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2393\">thoracic cavity<\/a><\/strong> is the more superior subdivision of the anterior cavity, and it is enclosed by the rib cage. The thoracic cavity contains the lungs and the heart, which is located in the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2395\">mediastinum<\/a>. The diaphragm forms the floor of the thoracic cavity and separates it from the more inferior abdominopelvic cavity. The <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2394\">abdominopelvic cavity<\/a><\/strong> is the largest cavity in the body. Although no membrane physically divides the abdominopelvic cavity, it can be useful to distinguish between the abdominal cavity, the division that houses the digestive organs, and the pelvic cavity, the division that houses the organs of reproduction.<\/p>\n<figure style=\"width: 1180px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/image6-7.png\" alt=\"image\" width=\"1180\" height=\"683\" \/><figcaption class=\"wp-caption-text\"><strong>Figure 6. Dorsal and Ventral Body Cavities.<\/strong> The ventral cavity includes the thoracic and abdominopelvic cavities and their subdivisions. The dorsal cavity includes the cranial and spinal cavities.<\/figcaption><\/figure>\n<p style=\"text-align: justify\"><strong>Abdominopelvic <\/strong><strong>Regions and Quadrants:<\/strong> To promote clear communication, for instance about the location of a patient\u2019s abdominal pain or a suspicious mass, health care providers typically divide up the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2394\">abdominopelvic cavity<\/a> into either nine regions or four quadrants (Figure 7).<\/p>\n<figure style=\"width: 1210px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/image7-6.png\" alt=\"image\" width=\"1210\" height=\"625\" \/><figcaption class=\"wp-caption-text\"><strong>Figure 7. Regions and Quadrants of the Abdominopelvic Cavity.<\/strong> There are (a) nine abdominopelvic regions and (b) four abdominopelvic quadrants in the peritoneal cavity.<\/figcaption><\/figure>\n<p style=\"text-align: justify\">The more detailed regional approach subdivides the cavity with one horizontal line immediately inferior to the ribs and one immediately superior to the pelvis, and two vertical lines drawn as if dropped from the midpoint of each clavicle (collarbone). There are nine resulting regions. The simpler quadrants approach, which is also commonly used in medicine, subdivides the cavity with one horizontal and one vertical line that intersect at the patient\u2019s umbilicus (navel).<\/p>\n<p style=\"text-align: justify\">These regions can be used to identify the location of abdominal organs more precisely.\u00a0 For example:<\/p>\n<ul>\n<li>The right <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2416\">hypochondriac region<\/a> contains the gall bladder and part of the liver, and the right kidney<\/li>\n<li>The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2417\">epigastric region<\/a> contains part of the liver and part of the stomach<\/li>\n<li>The left hypochondriac region contains part of the spleen and part of the stomach, and the left kidney<\/li>\n<li>The right <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2419\">lumbar region<\/a> contains most of the ascending <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2423\">colon<\/a><\/li>\n<li>The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2420\">umbilical region<\/a> contains the transverse colon and part of the small intestine<\/li>\n<li>The left lumbar region contains most of the descending colon<\/li>\n<li>The right <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2421\">iliac region<\/a> contains the appendix and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2424\">caecum<\/a><\/li>\n<li>The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2422\">hypogastric region<\/a> contains the lower small intestine, the distal sigmoid colon and anus, and the urinary bladder, as well as the uterus and ovaries in females and the prostate in males<\/li>\n<li>The left iliac region contains the proximal sigmoid colon<\/li>\n<\/ul>\n<p style=\"text-align: justify\"><strong>Membranes of the Anterior (Ventral) Body Cavity:<\/strong> A <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2425\">serous membrane<\/a><\/strong> (also referred to as a serosa) is one of the thin membranes that cover the walls and organs in the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2393\">thoracic<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2394\">abdominopelvic<\/a> cavities. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2426\">parietal<\/a> layers of the membranes line the walls of the body cavity (pariet- refers to a cavity wall). The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2427\">visceral<\/a> layer of the membrane covers the organs (the viscera). Between the parietal and visceral layers is a very thin, fluid-filled serous space, or cavity (Figure 8).<\/p>\n<p style=\"text-align: justify\">There are three serous cavities and their associated membranes. The <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2428\">pleura<\/a><\/strong> is the serous membrane that surrounds the lungs in the pleural cavity; the <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2140\">pericardium<\/a><\/strong> is the serous membrane that surrounds the heart in the pericardial cavity; and the <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1333_2429\">peritoneum<\/a><\/strong> is the serous membrane that surrounds several organs in the abdominopelvic cavity.<\/p>\n<figure style=\"width: 865px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/image8-6.png\" alt=\"image\" width=\"865\" height=\"431\" \/><figcaption class=\"wp-caption-text\"><strong>Figure 8. Serous Membrane.<\/strong> Serous membrane lines the pericardial cavity and reflects back to cover the heart\u2014much the same way that an underinflated balloon would form two layers surrounding a fist.<\/figcaption><\/figure>\n<p style=\"text-align: justify\">The serous membranes form fluid-filled sacs, or cavities, that cushion and reduce friction on internal organs when they move, such as when the lungs inflate or the heart beats. Both the parietal and visceral serosa secrete the thin, slippery serous fluid located within the serous cavities.<\/p>\n<p style=\"text-align: justify\">The pleural cavity reduces friction between the lungs and the body wall. Likewise, the pericardial cavity reduces friction between the heart and the wall of the pericardium. The peritoneal cavity reduces friction between the abdominal and pelvic organs and the body wall. Therefore, serous membranes provide additional protection to the viscera they enclose by reducing friction that could lead to inflammation of the organs.<\/p>\n<\/div>\n<div class=\"textbox textbox--exercises\">\n<header class=\"textbox__header\">\n<p class=\"textbox__title\"><a id=\"p\"><\/a>Practice Questions<\/p>\n<\/header>\n<div class=\"textbox__content\">\n<p><strong>Part 1:<\/strong> Body Systems<\/p>\n<div id=\"h5p-157\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-157\" class=\"h5p-iframe\" data-content-id=\"157\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"7-1\"><\/iframe><\/div>\n<\/div>\n<p><strong>Part 2:<\/strong> Anatomical Terminology<\/p>\n<div id=\"h5p-158\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-158\" class=\"h5p-iframe\" data-content-id=\"158\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"7-3\"><\/iframe><\/div>\n<\/div>\n<div id=\"h5p-159\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-159\" class=\"h5p-iframe\" data-content-id=\"159\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"7-4\"><\/iframe><\/div>\n<\/div>\n<div id=\"h5p-160\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-160\" class=\"h5p-iframe\" data-content-id=\"160\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"7-5\"><\/iframe><\/div>\n<\/div>\n<\/div>\n<\/div>\n<p>&nbsp;<\/p>\n<div class=\"glossary\"><span class=\"screen-reader-text\" id=\"definition\">definition<\/span><template id=\"term_1333_2350\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2350\"><div tabindex=\"-1\"><p>Group of organs that work together to carry out a particular function.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2351\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2351\"><div tabindex=\"-1\"><p>Living being that has a cellular structure and that can independently perform all physiologic functions necessary for life.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2218\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2218\"><div tabindex=\"-1\"><p>Group of many similar cells (though sometimes composed of a few related types) that work together to perform a specific function.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2217\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2217\"><div tabindex=\"-1\"><p>An anatomically distinct structure of the body composed of two or more tissue types.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2355\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2355\"><div tabindex=\"-1\"><p>Face down position.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2356\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2356\"><div tabindex=\"-1\"><p>Face up.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2357\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2357\"><div tabindex=\"-1\"><p>Describes the front or direction toward the front of the body; also referred to as ventral.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2358\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2358\"><div tabindex=\"-1\"><p>Describes the back or direction toward the back of the body; also referred to as dorsal.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2407\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2407\"><div tabindex=\"-1\"><p>Back of the knee.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2408\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2408\"><div tabindex=\"-1\"><p>Knee cap.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2359\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2359\"><div tabindex=\"-1\"><p>Describes a position above or higher than another part of the body proper; also referred to as cranial.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2406\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2406\"><div tabindex=\"-1\"><p>Mouth<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2360\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2360\"><div tabindex=\"-1\"><p>Describes a position below or lower than another part of the body proper; near or toward the tail (in humans, the coccyx, or lowest part of the spinal column); also referred to as caudal.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2409\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2409\"><div tabindex=\"-1\"><p>Lowest part of the vertebral column; 'tailbone'<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2361\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2361\"><div tabindex=\"-1\"><p>Describes the side or direction toward the side of the body.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2405\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2405\"><div tabindex=\"-1\"><p>Thumb<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2362\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2362\"><div tabindex=\"-1\"><p>Describes the middle or direction toward the middle of the body.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2404\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2404\"><div tabindex=\"-1\"><p>Big toe<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2372\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2372\"><div tabindex=\"-1\"><p>Describes a position between a more medial and a more lateral structure.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2373\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2373\"><div tabindex=\"-1\"><p>Describes a position in a limb that is nearer to the point of attachment or the trunk of the body.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2381\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2381\"><div tabindex=\"-1\"><p>Upper arm, between shoulder and elbow.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2382\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2382\"><div tabindex=\"-1\"><p>Lower arm, between elbow and wrist.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2374\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2374\"><div tabindex=\"-1\"><p>Describes a position in a limb that is farther from the point of attachment or the trunk of the body.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2379\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2379\"><div tabindex=\"-1\"><p>Thigh bone; the single bone of the thigh.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2375\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2375\"><div tabindex=\"-1\"><p>(In anatomy) describes a position towards the middle (centre) of a structure or organ system.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2376\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2376\"><div tabindex=\"-1\"><p>Describes a position towards the outer edge (periphery) of a structure or organ system.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2377\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2377\"><div tabindex=\"-1\"><p>Describes a position closer to the surface of the body.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2378\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2378\"><div tabindex=\"-1\"><p>(In anatomy) describes a position farther from the surface of the body.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2383\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2383\"><div tabindex=\"-1\"><p>(In anatomy) imaginary two-dimensional surface that passes through the body.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2384\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2384\"><div tabindex=\"-1\"><p>Two-dimensional, vertical plane that divides the body or organ into right and left sides.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2386\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2386\"><div tabindex=\"-1\"><p>A sagittal plane on the midline, dividing the body into equal left and right halves (also medial plane).<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2385\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2385\"><div tabindex=\"-1\"><p>A sagittal plane that does not divide the body into equal left and right halves (also longitudinal section).<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2387\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2387\"><div tabindex=\"-1\"><p>Two-dimensional, vertical plane that divides the body or organ into anterior and posterior portions.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2388\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2388\"><div tabindex=\"-1\"><p>Two-dimensional, horizontal plane that divides the body or organ into superior and inferior portions.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2389\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2389\"><div tabindex=\"-1\"><p>Posterior body cavity that houses the brain and spinal cord; also referred to the posterior body cavity.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2390\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2390\"><div tabindex=\"-1\"><p>Larger body cavity located anterior to the posterior (dorsal) body cavity; includes the serous membrane-lined pleural cavities for the lungs, pericardial cavity for the heart, and peritoneal cavity for the abdominal and pelvic organs; also referred to as anterior body cavity.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2391\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2391\"><div tabindex=\"-1\"><p>Division of the posterior (dorsal) cavity that houses the brain.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2392\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2392\"><div tabindex=\"-1\"><p>Division of the dorsal cavity that houses the spinal cord; also referred to as vertebral cavity.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2137\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2137\"><div tabindex=\"-1\"><p>Circulatory medium within the CNS that is produced by ependymal cells in the choroid plexus filtering the blood.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2393\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2393\"><div tabindex=\"-1\"><p>Division of the anterior (ventral) cavity that houses the heart, lungs, esophagus, and trachea.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2395\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2395\"><div tabindex=\"-1\"><p>A central compartment in the thoracic cavity located intermediate to the left and right pleural cavities.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2394\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2394\"><div tabindex=\"-1\"><p>Division of the anterior (ventral) cavity that houses the abdominal and pelvic viscera.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2416\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2416\"><div tabindex=\"-1\"><p>Abdominopelvic region (left or right) located under the lowest ribs in the superior corners of the abdominopelvic cavity.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2417\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2417\"><div tabindex=\"-1\"><p>Abdominopelvic region located in the central superior area below the xiphoid process.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2419\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2419\"><div tabindex=\"-1\"><p>Left or right central abdominopelvic region.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2423\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2423\"><div tabindex=\"-1\"><p>Portion of the large intestine.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2420\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2420\"><div tabindex=\"-1\"><p>central abdominopelvic region including the belly button.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2421\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2421\"><div tabindex=\"-1\"><p>Abdominopelvic region in the left or right inferior corners of the abdomen, below the hip bone.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2424\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2424\"><div tabindex=\"-1\"><p>Beginning of the large intestine, forming a small pouch.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2422\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2422\"><div tabindex=\"-1\"><p>Central inferior abdominopelvic region.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2425\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2425\"><div tabindex=\"-1\"><p>Membrane that covers organs and reduces friction; also referred to as serosa.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2426\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2426\"><div tabindex=\"-1\"><p>Facing the body wall.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2427\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2427\"><div tabindex=\"-1\"><p>Facing the organs (opposite of parietal).<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2428\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2428\"><div tabindex=\"-1\"><p>Serous membrane that lines the pleural cavity and covers the lungs.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2140\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2140\"><div tabindex=\"-1\"><p>Cavity surrounding the heart filled with a lubricating serous fluid that reduces friction as the heart contracts (also, pericardial cavity or cardiac sac).<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1333_2429\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1333_2429\"><div tabindex=\"-1\"><p>Serous membrane that lines the abdominopelvic cavity and covers the organs found there.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><\/div>","protected":false},"author":10,"menu_order":7,"template":"","meta":{"pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"class_list":["post-1333","chapter","type-chapter","status-publish","hentry"],"part":19,"_links":{"self":[{"href":"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-json\/pressbooks\/v2\/chapters\/1333","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-json\/wp\/v2\/users\/10"}],"version-history":[{"count":25,"href":"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-json\/pressbooks\/v2\/chapters\/1333\/revisions"}],"predecessor-version":[{"id":3257,"href":"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-json\/pressbooks\/v2\/chapters\/1333\/revisions\/3257"}],"part":[{"href":"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-json\/pressbooks\/v2\/parts\/19"}],"metadata":[{"href":"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-json\/pressbooks\/v2\/chapters\/1333\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-json\/wp\/v2\/media?parent=1333"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-json\/pressbooks\/v2\/chapter-type?post=1333"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-json\/wp\/v2\/contributor?post=1333"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-json\/wp\/v2\/license?post=1333"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}