tissue that is enlarged due to an increased number of new cells


Physiology is the study of the function of cells, tissues and organs

acute inflammation

inflammatory response that occurs from the time of injury to infection up to a few days


the pressure/resistance against which the heart must work in order to eject blood for each contraction


Genetic disorder that affects the skin, in which there is no melanin production.

alpha cell

pancreatic islet cell type that produces the hormone glucagon


A protease inhibitor that protects tissues from proteases released by inflammatory cells

Alveolar dead space

Air space within alveoli that are unable to participate in gas exchange.

alveolar duct

Small tube that leads from the terminal bronchiole to the respiratory bronchiole and is the point of attachment for alveoli.

alveolar macrophages

Immune system cell of the alveolus that removes debris and pathogens.

alveolar pores

Opening that allows airflow between neighboring alveoli.

alveolar sac

Cluster of alveoli.


Small, grape-like sac that performs gas exchange in the lungs.

amount of force

Amount of force that is exerted by gases in the air surrounding any given surface.


Third stage of mitosis (and meiosis), during which sister chromatids separate into two new nuclear regions of a dividing cell.


(plural = anastomoses) area where vessels unite to allow blood to circulate even if there may be partial blockage in another branch

Anatomic Pathologists

Pathology specialty that looks at organs and tissues to determine what changes, if any, are occurring that might lead to an explanation for the signs and symptoms.

anatomical dead space

Air space present in the airway that never reaches the alveoli and therefore never participates in gas exchange.

anchoring junctions

Mechanically attaches adjacent cells to each other or to the basement membrane.


abnormal ballooning/ widening of the blood vessel wall cause by it's weakness. Aneurysm rupture is very dangerous and often fatal

anterior cardiac veins

vessels that parallel the small cardiac arteries and drain the anterior surface of the right ventricle; bypass the coronary sinus and drain directly into the right atrium

anterior interventricular artery

(also, left anterior descending artery or LAD) major branch of the left coronary artery that follows the anterior interventricular sulcus

anterior interventricular sulcus

sulcus located between the left and right ventricles on the anterior surface of the heart

aortic valve

(also, aortic semilunar valve) valve located at the base of the aorta


The part of a cell or tissue which, in general, faces an open space.

apneustic center

Network of neurons within the pons that stimulate the neurons in the dorsal respiratory group; controls the depth of inspiration.

apocrine secretion

Release of a substance along with the apical portion of the cell.


"programmed" cells death that eliminates abnormal cells


(also, resistance vessel) very small artery that leads to a capillary

arteriovenous anastomosis

short vessel connecting an arteriole directly to a venule and bypassing the capillary beds


blood vessel that conducts blood away from the heart; may be a conducting or distributing vessel

ascending aorta

part of the aorta that originates from the heart; total length - around 5 cm


abnormal collection of fluid in the abdominal cavity


acute atherosclerotic cardiovascular disease


same as atherosclerotic plaque

atrioventricular septum

cardiac septum located between the atria and ventricles; atrioventricular valves are located here

atrioventricular valves

one-way valves located between the atria and ventricles; the valve on the right is called the tricuspid valve, and the one on the left is the mitral or bicuspid valve


(plural = atria) upper or receiving chamber of the heart that pumps blood into the lower chambers just prior to their contraction; the right atrium receives blood from the systemic circuit that flows into the right ventricle; the left atrium receives blood from the pulmonary circuit that flows into the left ventricle


extension of an atrium visible on the superior surface of the heart


listening with a stethoscope for changes in sounds produced by movement of air, blood, food digestion, etc.


heart’s ability to control its own contractions

basal cells

Type of stem cell found in the stratum basale and in the hair matrix that continually undergoes cell division, producing the keratinocytes of the epidermis.

basal lamina

Thin extracellular layer that lies underneath epithelial cells and separates them from other tissues.

basement membrane

In epithelial tissue, a thin layer of fibrous material that anchors the epithelial tissue to the underlying connective tissue; made up of the basal lamina and reticular lamina.

beta cell

pancreatic islet cell type that produces the hormone insulin

bicuspid valve

(also, mitral valve or left atrioventricular valve) valve located between the left atrium and ventricle; consists of two flaps of tissue


part of the blood vessel where it splits in 2 branches




alkaline solution produced by the liver and important for the emulsification of lipids

bile canaliculus

small ducts between hepatocytes that collects bile


main bile pigment, which is responsible for the brown color of feces


Eextraction of sample cells or tissues for examination to determine the presence or extent of a disease. The tissue is examined under a microscope by a pathologist for histological changes

blood flow

movement of blood through a vessel, tissue, or organ that is usually expressed in terms of volume per unit of time

blood pressure

force exerted by the blood against the wall of a vessel or heart chamber; can be described with the more generic term hydrostatic pressure

Bowman’s capsule

cup-shaped sack lined by a simple squamous epithelium (parietal surface) and specialized cells called podocytes (visceral surface) that participate in the filtration process; receives the filtrate which then passes on to the PCTs

Bowman’s Space

The space surrounding the glomerulus that the filtrate initially passes into.

Boyle’s law

Relationship between volume and pressure as described by the formula: P1V1 = P2V2


a pro-inflammatory peptide with many vasoactive and inflammatory effects

bronchial tree

Collective name for the multiple branches of the bronchi and bronchioles of the respiratory system.


branch of bronchi that are 1 mm or less in diameter and terminate at alveolar sacs


Branch of bronchi that are 1 mm or less in diameter and terminate at alveolar sacs.


decrease in the size of the bronchiole due to contraction of the muscular wall


increase in the size of the bronchiole due to contraction of the muscular wall

Brush Border

A feature of the cells of the proximal convoluted tubule that creates increased surface area for absorption.


cup-like structures receiving urine from the collecting ducts where it passes on to the renal pelvis and ureter


ability of a vein to distend and store blood

capacitance vessels



smallest of blood vessels where physical exchange occurs between the blood and tissue cells surrounded by interstitial fluid

capillary bed

network of 10–100 capillaries connecting arterioles to venules

cardiac notch

depression in the medial surface of the inferior lobe of the left lung where the apex of the heart is located

Cardiac output

measurement of blood flow from the heart through the ventricles, is usually measured in liters per minute

cardiac skeleton

(also, skeleton of the heart) reinforced connective tissue located within the atrioventricular septum; includes four rings that surround the openings between the atria and ventricles, and the openings to the pulmonary trunk and aorta; the point of attachment for the heart valves


muscle cell of the heart

cell cycle

Life cycle of a single cell, from its birth until its division into two new daughter cells.

cell junctions

Point of cell-to-cell contact that connects one cell to another in a tissue.

central chemoreceptor

One of the specialized receptors that are located in the brain that sense changes in hydrogen ion, oxygen, or carbon dioxide concentrations in the brain.

central vein

vein that receives blood from hepatic sinusoids


Region of attachment for two sister chromatids.


Cellular structure that organizes microtubules during cell division.


Progress point in the cell cycle during which certain conditions must be met in order for the cell to proceed to a subsequence phase.

chordae tendineae

string-like extensions of tough connective tissue that extend from the flaps of the atrioventricular valves to the papillary muscles

chronic inflammation

a slow, long-term inflammation, in response to repeated injury, lasting for weeks, months to years.

circumflex artery

branch of the left coronary artery that follows coronary sulcus

cleavage furrow

Contractile ring that forms around a cell during cytokinesis that pinches the cell into two halves.

Clinical Chemists

Specialty that works with Medical Biochemists and Medical Laboratory Technologists to run laboratory services and equipment for the testing of chemicals in specimens such as blood, and urine.

clinical manifestations

symptoms that a person experiences because they have a disease

clinical reasoning

the process which information (e.g. lab findings, physical exam results, previous clinical experience) AND the patient's context results in an understanding of a patient's
problem or disease; thus aiding with treatment plan and interventions.

common bile duct

structure formed by the union of the common hepatic duct and the gallbladder’s cystic duct

common hepatic duct

duct formed by the merger of the two hepatic ducts

common iliac artery

a large artery that carries oxydenated blood to lower limbs, pelvis, and reproductive organs


degree to which a blood vessel can stretch as opposed to being rigid

conducting zone

Region of the respiratory system that includes the organs and structures that provide passageways for air and are not directly involved in gas exchange.

congestive heart failure (CHF)

heart is too weak or damaged to fill and pump efficiently resulting in blood pooling upstream (i.e. into lungs for left-sided and venous system for right-sided)

continuous capillary

most common type of capillary, found in virtually all tissues except epithelia and cartilage; contains very small gaps in the endothelial lining that permit exchange


Chronic Obstructive Pulmonary Disease is an umbrella term for chronic pulmonary diseases that progressively narrows & obstructs the airways - especially during exhalation. This makes it progressively harder to breathe. Emphysema and chronic bronchitis are the most common examples of COPD

cor pulmonale

alteration in the structure and function of the right ventricle caused by pulmonary hypertension


arteries that supply heart muscle

Coronary arteries

branches of the ascending aorta that supply blood to the heart; the left coronary artery feeds the left side of the heart, the left atrium and ventricle, and the interventricular septum; the right coronary artery feeds the right atrium, portions of both ventricles, and the heart conduction system

coronary sinus

large, thin-walled vein on the posterior surface of the heart that lies within the atrioventricular sulcus and drains the heart myocardium directly into the right atrium

coronary sulcus

sulcus that marks the boundary between the atria and ventricles

coronary veins

vessels that drain the heart and generally parallel the large surface arteries

critical thinking

analysis of a problem/situation and the data or evidence related to it


blue/purple colour of the skin or mucous membranes due to the blood & tissues near the skin surface having low oxygen.


One of a group of proteins that function in the progression of the cell cycle.

cyclin-dependent kinase

One of a group of enzymes associated with cyclins that help them perform their functions.

cystic duct

duct through which bile drains and enters the gallbladder


small proteins released by cells; allow for communication between the cells involved in the same type of immune response/reaction


Final stage in cell division, where the cytoplasm divides to form two separate daughter cells.

delta cell

minor cell type in the pancreas that secretes the hormone somatostatin

dermal papilla

(plural = dermal papillae) extension of the papillary layer of the dermis that increases surface contact between the epidermis and dermis.

dermal papilla (plural = dermal papillae)

Extension of the papillary layer of the dermis that increases surface contact between the epidermis and dermis.


Layer of skin between the epidermis and hypodermis, composed mainly of connective tissue and containing blood vessels, hair follicles, sweat glands, and other structures.


Structure that forms an impermeable junction between cells.


cell structure that anchors the ends of cardiac muscle fibers to allow contraction to occur

detrusor muscle

smooth muscle in the bladder wall; fibers run in all directions to reduce the size of the organ when emptying it of urine

diabetes mellitus

a condition caused by destruction or dysfunction of the beta cells of the pancreas or cellular resistance to insulin that results in abnormally high blood glucose levels


movement of blood cells through the blood vessel wall


relaxation of ventricles during the cardiac cycle

diastolic failure

The left ventricle can't fill well during diastole because the ventricular walls can't relax well and/or the ventricular lumen size is reduced

diastolic pressure

lower number recorded when measuring arterial blood pressure; represents the minimal value corresponding to the pressure that remains during ventricular relaxation




condition marked by the Presence of a double complement of genetic material (two sets of chromosomes, one set inherited from each of two parents).


A disorder of structure and function that may produce specific signs and symptoms but is not caused by a direct injury.


injury to the inner layer of the vessel, separation (tear) of blood vessel wall that allows for blood to flow between the layers; a medical emergency

distal convoluted tubule

portions of the nephron distal to the loop of Henle that receive hyposmotic filtrate from the loop of Henle and empty into collecting ducts

Dorsal respiratory group (DRG)

Region of the medulla oblongata that stimulates the contraction of the diaphragm and intercostal muscles to induce inspiration.


a feeling of not being able to breathe well enough; short of breath


bleeds under the skin, greater than 1 cm
Ecchymosis (singular)


'swelling' of tissue, most often due to increased fluid in the interstitial spaces

efferent arteriole

arteriole carrying blood from the glomerulus to the capillary beds around the convoluted tubules and loop of Henle; portion of the portal system

elastic artery

(also, conducting artery) artery with abundant elastic fibers located closer to the heart, which maintains the pressure gradient and conducts blood to smaller branches

elastin fibers

Fibers made of the protein elastin that increase the elasticity of the dermis.


Clear protein-bound lipid found in the stratum lucidum that is derived from keratohyalin and helps to prevent water loss.


unattached mass that travels through the bloodstream and can create blockages, resulting in acute vascular events


a chronic obstructive pulmonary disease. Continual injury to lung tissue causes chronic inflammation and remodeling resulting in a loss of lung elasticity that is key to passive exhalation. This causes an 'obstruction' during exhalation.


a substtance that helps mix two liquids


innermost layer of the heart lining the heart chambers and heart valves; composed of endothelium reinforced with a thin layer of connective tissue that binds to the myocardium

endocrine gland

Groups of cells that release chemical signals into the intercellular fluid to be picked up and transported to their target organs by blood.


Tissue that lines vessels of the lymphatic and cardiovascular system, made up of a simple squamous epithelium.

enterohepatic circulation

recycling mechanism that conserves bile salts


protein(s) that accelerate chemical reactions and transform substrate(s) into product(s)


Eosin is a pink acidic dye that stains basic elements such as most proteins in the tissue pink or red

epicardial coronary arteries

surface arteries of the heart that generally follow the sulci


innermost layer of the serous pericardium and the outermost layer of the heart wall


Outermost tissue layer of the skin.


upper abdomen, below the ribs


The layer of cells that covers all internal and external surfaces of the body


increased blood in tissue, resulting in visible redness and increased heat


a sudden worsening of a disease or an increase in its symptoms

exocrine gland

Group of epithelial cells that secrete substances through ducts that open to the skin or to internal body surfaces that lead to the exterior of the body.


Also, exhalation, process that causes the air to leave the lungs.

Expiratory reserve volume

Amount of air that can be forcefully exhaled after a normal tidal exhalation.

external elastic membrane

membrane composed of elastic fibers that separates the tunica media from the tunica externa; seen in larger arteries

fenestrated capillary

type of capillary with pores or fenestrations in the endothelium that allow for rapid passage of certain small materials


The percentage of the total volume of air that can forcibly be blown out in first second, after full inhalation. FEV1 in healthy people is >80%, depending on age, sex, height, mass and ethnicity


a systemic inflammatory response that extends beyond the site of infection and affects the entire body, resulting in an overall increase in body temperature

fibroelastic membrane

Specialized membrane that connects the ends of the C-shape cartilage in the trachea; contains smooth muscle fibers.

foramen ovale

opening in the fetal heart that allows blood to flow directly from the right atrium to the left atrium, bypassing the fetal pulmonary circuit

forced breathing

Also, hyperpnea, mode of breathing that occurs during exercise or by active thought that requires muscle contraction for both inspiration and expiration.

Forensic Pathologists


fossa ovalis

oval-shaped depression in the interatrial septum that marks the former location of the foramen ovale

functional residual capacity (FRC)

Sum of ERV and RV, which is the amount of air that remains in the lungs after a tidal expiration.

G0 phase

Phase of the cell cycle, usually entered from the G1 phase; characterized by long or permanent periods where the cell does not move forward into the DNA synthesis phase.

G1 phase

First phase of the cell cycle, after a new cell is born.

G2 phase

Third phase of the cell cycle, after the DNA synthesis phase.


accessory digestive organ that stores and concentrates bile

gap junctions

Allows cytoplasmic communications to occur between cells.

glomerular filtration rate

rate of renal filtration


tuft or cluster of capillaries surrounded by Bowman’s capsule; filters the blood based on molecular size


pancreatic hormone that stimulates the catabolism of glycogen to glucose, thereby increasing blood glucose levels

goblet cell

Unicellular gland found in columnar epithelium that secretes mucous.


pockets of infected tissue walled off and surrounded by white blood cells

great cardiac vein

vessel that follows the interventricular sulcus on the anterior surface of the heart and flows along the coronary sulcus into the coronary sinus on the posterior surface; parallels the anterior interventricular artery and drains the areas supplied by this vessel

gut microbiota

collection of microorganisms (bacteria, fungi, viruses, and other) in person's gastrointestinal system


high-density lipoproteins, responsible for carrying cholesterol out of the bloodstream and into the liver; commonly referred to as "good cholesterol"




A blue basic dye that is used to stain tissues. It turns acidic elements such as RNA and DNA in the tissue blue.



hepatic artery

artery that supplies oxygenated blood to the liver

hepatic lobule

hexagonal-shaped structure composed of hepatocytes that radiate outward from a central vein

hepatic portal vein

vein that supplies deoxygenated nutrient-rich blood to the liver

hepatic sinusoids

blood capillaries between rows of hepatocytes that receive blood from the hepatic portal vein and the branches of the hepatic artery

hepatic vein

vein that drains into the inferior vena cava


major functional cells of the liver


concave structure on the mediastinal surface of the lungs where blood vessels, lymphatic vessels, nerves, and a bronchus enter the lung


Histopathology is the study of the tissues to identify changes at the cellular or microscopic level.

holocrine secretion

Release of a substance caused by the rupture of a gland cell, which becomes part of the secretion.


uniform in composition or character (i.e. color, shape, size, texture, etc.)


Describes two copies of the same chromosome (not identical), one inherited from each parent.


elevated blood pressure

hypertrophic cardiomyopathy

pathological enlargement of the heart, generally for no known reason


tissue is enlarged due to each individual cell becoming larger, often with an increase of cytoplasmic contents such as contractile proteins as in the case with muscle tissue


abnormally high levels of fluid and blood within the body


Connective tissue connecting the integument to the underlying bone and muscle.


part of the brain below the thalamus that is an important interface between the central nervous system and vasculature. Amongst its many functions, it plays a major role in hormonal secretion, temperature and fluid homeostasis, and emotional regulation.


decrease in blood volume


lack of oxygen supply to the tissues

Infectious Disease


inferior vena cava

large systemic vein that returns blood to the heart from the inferior portion of the body


a necessary process that recruits the cellular defenses needed to eliminate pathogens, remove damaged and dead cells, and initiate repair mechanisms


Also, inhalation, process that causes air to enter the lungs.

Inspiratory capacity (IC)

Sum of the TV and IRV, which is the amount of air that can maximally be inhaled past a tidal expiration.

Inspiratory reserve volume (IRV)

Amount of air that enters the lungs due to deep inhalation past the tidal volume.


pancreatic hormone that enhances the cellular uptake and utilization of glucose, thereby decreasing blood glucose levels

integumentary system

Skin and its accessory structures.

interatrial septum

cardiac septum located between the two atria; contains the fossa ovalis after birth

intercalated discs

part of the sarcolemma that connects cardiac tissue, and contains gap junctions and desmosomes

internal elastic membrane

membrane composed of elastic fibers that separates the tunica intima from the tunica media; seen in larger arteries


Entire life cycle of a cell, excluding mitosis.

interventricular septum

cardiac septum located between the two ventricles

intestinal microvillus

finger-like projection of the lining of the small intestine; a primary surface of nutrient absorption in the digestive system

intra-alveolar pressure

Intrapulmonary pressure, pressure of the air within the alveoli.

intrapleural pressure

Pressure of the air within the pleural cavity.


insufficient blood flow to the tissues


Type of structural protein that gives skin, hair, and nails its hard, water-resistant properties.


Cell that produces keratin and is the most predominant type of cell found in the epidermis.


Granulated protein found in the stratum granulosum.


Region of a centromere where microtubules attach to a pair of sister chromatids.

Korotkoff sounds

noises created by turbulent blood flow through the vessels


type of fluid flow in which fluid travels smoothly

Langerhans cell

Specialized dendritic cell found in the stratum spinosum that functions as a macrophage.


Portion of the pharynx bordered by the oropharynx superiorly and esophagus and trachea inferiorly; serves as a route for both air and food.


Cartilaginous structure that produces the voice, prevents food and beverages from entering the trachea, and regulates the volume of air that enters and leaves the lungs.


low-density lipoprotein, "bad cholesterol" , the form that carries lipids from the liver to various body tissue; increased levels of LDL can accumulate within the blood vessel wall and cause atherosclerosis

left atrioventricular valve

(also, mitral valve or bicuspid valve) valve located between the left atrium and ventricle; consists of two flaps of tissue


cellular component of blood, also known as white blood cells; part of the immune system


an enzyme that breaks down fat


A family of organic compounds composed of carbon, hydrogen, and oxygen. They are insoluble in water. The three main types of lipids are triglycerides, phospholipids, and sterols.


a particle that consists a protein and a lipid (triglyceride or cholesterol). The main function of lipoproteins is to transport lipids through the bloodstream to various body tissues/organs


largest gland in the body whose main digestive function is the production of bile

loop of Henle

descending and ascending portions between the proximal and distal convoluted tubules

loose connective tissue 

a type of connective tissue that consists of fibroblasts, a large amount of extracellular matrix (also called ground substance), and space connective tissue fibers (collagen, elastin). Loose connective tissue often contains cappillaries, arterioles, and venules that supply epithelium on top of it


interior of a tubular structure such as a blood vessel or a portion of the alimentary canal through which blood, chyme, or other substances travel


organ of the respiratory system that performs gas exchange

lymphatic filariasis

parasitic worms that live in the lymphatic vessels causing a chronic inflammatory response. This results in blockage of lymph flow causing edema, repeated infections, skin thickening and fibrosis.

marginal arteries

branches of the right coronary artery that supply blood to the superficial portions of the right ventricle

mean arterial pressure (MAP)

average driving force of blood to the tissues; approximated by taking diastolic pressure and adding 1/3 of pulse pressure


One of three recesses (superior, middle, and inferior) in the nasal cavity attached to the conchae that increase the surface area of the nasal cavity.

Medical Biochemists


Medical Microbiologists



inner region of kidney containing the renal pyramids


Pigment that determines the color of hair and skin.


Cell found in the stratum basale of the epidermis that produces the pigment melanin.


Cells that produce the brown/black pigment melanin. They are located in select parts of the body, but most visible at the bottom layer (the stratum basale) of the skin's epidermis and the middle layer of the eye (the uvea)


Intercellular vesicle that transfers melanin from melanocytes into keratinocytes of the epidermis.

Merkel cell

Receptor cell in the stratum basale of the epidermis that responds to the sense of touch.

Merocrine secretion

Release of a substance from a gland via exocytosis.


Simple squamous epithelial tissue which covers the major body cavities and is the epithelial portion of serous membranes.


Second stage of mitosis (and meiosis), characterized by the linear alignment of sister chromatids in the center of the cell.

metaphase plate

Linear alignment of sister chromatids in the center of the cell, which takes place during metaphase.


short vessel arising from a terminal arteriole that branches to supply a capillary bed


cancerous growth spreads beyond its original site - often breaching the basement membrane and invading nearby tissues or entering lymphatic/blood circulation


a term that encompasses not only microorganisms that inhabit certain environments, but also their genomes and surronding environmental conditions


microorganisms (bacteria, fungi, viruses) that inhabit multicellular organisms (including humans) and affect immunological, hormonal, and metabolic health of the host


blood flow through the capillaries

middle cardiac vein

vessel that parallels and drains the areas supplied by the posterior interventricular artery; drains into the great cardiac vein


Division of genetic material, during which the cell nucleus breaks down and two new, fully functional, nuclei are formed.

mitotic phase

Network of microtubules, originating from centrioles, that arranges and pulls apart chromosomes during mitosis.

mitral valve

(also, left atrioventricular valve or bicuspid valve) valve located between the left atrium and ventricle; consists of two flaps of tissue

moderator band

band of myocardium covered by endocardium that arises from the inferior portion of the interventricular septum in the right ventricle and crosses to the anterior papillary muscle; contains conductile fibers that carry electrical signals followed by contraction of the heart


a type of white blood cell that can further differentiate in macrophages and is involved in adaptive immunity and inflammation

mucous gland

A group of cells that secrete mucous, a thick, slippery substance that keeps tissues moist and acts as a lubricant.


Describes the condition of being able to differentiate into different types of cells within a given cell lineage or small number of lineages, such as a red blood cell or white blood cell.

muscular artery

(also, distributing artery) artery with abundant smooth muscle in the tunica media that branches to distribute blood to the arteriole network


a type of relationship between two organisms, species, where both parties benefit from the relationship


thickest layer of the heart composed of cardiac muscle cells built upon a framework of primarily collagenous fibers and blood vessels that supply it and the nervous fibers that help to regulate it

nasal cells

Type of stem cell found in the stratum basale and in the hair matrix that continually undergoes cell division, producing the keratinocytes of the epidermis.


Portion of the pharynx flanked by the conchae and oropharynx that serves as an airway.


functional units of the kidney that carry out filtration and modification to produce urine; consist of renal corpuscles, proximal and distal convoluted tubules, and descending and ascending loops of Henle; drain into collecting ducts

nervi vasorum

small nerve fibers found in arteries and veins that trigger contraction of the smooth muscle in their walls

net filtration pressure

pressure of fluid across the glomerulus; calculated by taking the hydrostatic pressure of the capillary and subtracting the colloid osmotic pressure of the blood and the hydrostatic pressure of Bowman’s capsule




Describes the condition of being more specialized than multipotency; the condition of being able to differentiate into one of a few possible cell types.


Mutated version of a normal gene involved in the positive regulation of the cell cycle.


extracellular proteins that mark it to be be phagocytosed


Portion of the pharynx flanked by the nasopharynx, oral cavity, and laryngopharynx that is a passageway for both air and food.


"upward" direction. Growth towards the outer, epidermal surface


care provider feels (tactile sensation) a part of the body for changes in firmness, size, location, etc


Pathogen-associated molecular patterns are small molecular motifs conserved within a class of microbes.


organ with both exocrine and endocrine functions located posterior to the stomach that is important for digestion and the regulation of blood glucose

pancreatic islets

specialized clusters of pancreatic cells that have endocrine functions; also called islets of Langerhans

pancreatic juice

secretion of the pancreas containing digestive enzymes and bicarbonate

papillary layer

Superficial layer of the dermis, made of loose, areolar connective tissue.

papillary muscle

extension of the myocardium in the ventricles to which the chordae tendineae attach

parietal pleura

outermost layer of the pleura that connects to the thoracic wall, mediastinum, and diaphragm


Specialized doctors who are able to identify abnormal changes in tissues and organs.


Pathology is the study of abnormal changes to cells, tissues and organs that negatively impacts their structure or function


Pathophysiology is the study of the changes in function that are detrimental.

pectinate muscles

muscular ridges seen on the anterior surface of the right atrium


distribution of blood into the capillaries so the tissues can be supplied

pericardial cavity

cavity surrounding the heart filled with a lubricating serous fluid that reduces friction as the heart contracts

pericardial sac

(also, pericardium) membrane that separates the heart from other mediastinal structures; consists of two distinct, fused sublayers: the fibrous pericardium and the parietal pericardium


(also, pericardial sac) membrane that separates the heart from other mediastinal structures; consists of two distinct, fused sublayers: the fibrous pericardium and the parietal pericardium

peripheral artery disease

the narrowing or blockage of arteries that supply upper/lower limbs

peripheral chemoreceptor

One of the specialized receptors located in the aortic arch and carotid arteries that sense changes in pH, carbon dioxide, or oxygen blood levels.

peritubular capillary

second capillary bed of the renal portal system; surround the proximal and distal convoluted tubules; associated with the vasa recta


tiny pinpoint bleeds


Region of the conducting zone that forms a tube of skeletal muscle lined with respiratory epithelium; located between the nasal conchae and the esophagus and trachea.

pleural cavity

space between the visceral and parietal pleurae

pleural fluid

substance that acts as a lubricant for the visceral and parietal layers of the pleura during the movement of breathing


Describes the condition of being able to differentiate into a large variety of cell types.

pneumotaxic centers

Network of neurons within the pons that inhibit the activity of the neurons in the dorsal respiratory group; controls rate of breathing.


Specialized cells present in the glomeruli of the kidneys that create the filtration barrier, allowing fluid and small molecules to pass through while keeping larger proteins and cells in the blood.

porta hepatis

“gateway to the liver” where the hepatic artery and hepatic portal vein enter the liver

portal triad

bile duct, hepatic artery branch, and hepatic portal vein branch

posterior cardiac vein

vessel that parallels and drains the areas supplied by the marginal artery branch of the circumflex artery; drains into the great cardiac vein

posterior interventricular artery

(also, posterior descending artery) branch of the right coronary artery that runs along the posterior portion of the interventricular sulcus toward the apex of the heart and gives rise to branches that supply the interventricular septum and portions of both ventricles

posterior interventricular sulcus

sulcus located between the left and right ventricles on the anterior surface of the heart

PP cell

minor cell type in the pancreas that secretes the hormone pancreatic polypeptide

precapillary sphincters

circular rings of smooth muscle that surround the entrance to a capillary and regulate blood flow into that capillary


long term health outcome


First stage of mitosis (and meiosis), characterized by breakdown of the nuclear envelope and condensing of the chromatin to form chromosomes.


A general term for an enzyme that the breaks down proteins into smaller polypeptides or amino acids.


Normal gene that when mutated becomes an oncogene.

proximal convoluted tubule

twisted tubules receiving filtrate from Bowman’s capsule; most active part of the nephron in reabsorption and secretion

Pseudostratified columnar epithelium

Tissue that consists of a single layer of irregularly shaped and sized cells that give the appearance of multiple layers; found in ducts of certain glands and the upper respiratory tract.

pulmonary arteries

left and right branches of the pulmonary trunk that carry deoxygenated blood from the heart to each of the lungs

pulmonary artery

artery that arises from the pulmonary trunk and carries deoxygenated, arterial blood to the alveoli

pulmonary capillaries

capillaries surrounding the alveoli of the lungs where gas exchange occurs: carbon dioxide exits the blood and oxygen enters

pulmonary circuit

blood flow to and from the lungs

pulmonary plexus

network of autonomic nervous system fibers found near the hilum of the lung

pulmonary surfactant

Substance composed of phospholipids and proteins that reduces the surface tension of the alveoli; made by type II alveolar cells.

pulmonary trunk

large arterial vessel that carries blood ejected from the right ventricle; divides into the left and right pulmonary arteries

pulmonary valve

(also, pulmonary semilunar valve, the pulmonic valve, or the right semilunar valve) valve at the base of the pulmonary trunk that prevents backflow of blood into the right ventricle; consists of three flaps

pulmonary veins

veins that carry highly oxygenated blood into the left atrium, which pumps the blood into the left ventricle, which in turn pumps oxygenated blood into the aorta and to the many branches of the systemic circuit

Pulmonary ventilation

Exchange of gases between the lungs and the atmosphere; breathing.


alternating expansion and recoil of an artery as blood moves through the vessel; an indicator of heart rate

pulse pressure

difference between the systolic and diastolic pressures


sign of bleeding under the skin, up to 1cm


a protein-rich fluid formed at the site of inflammation during bacterial or fungal infection. Filled with dead cells and leukocytes, pus is typically white-yellow, yellow, or yellow-brown.


chemicals that effect the temperature set point in the hypothalamus, thus elevating body temperature and causing fever.

Quiet breathing

Also, eupnea, mode of breathing that occurs at rest and does not require the cognitive thought of the individual.

renal columns

extensions of the renal cortex into the renal medulla; separates the renal pyramids; contains blood vessels and connective tissues

renal corpuscle

consists of the glomerulus and Bowman’s capsule

renal cortex

outer part of kidney containing all of the nephrons; some nephrons have loops of Henle extending into the medulla

renal hilum

medial area of the kidney through which the renal artery, renal vein, ureters, lymphatics, and nerves pass

renal papillae

medullary area of the renal pyramids where collecting ducts empty urine into the minor calyces

renal pyramids

six to eight cone-shaped tissues in the medulla of the kidney containing collecting ducts and the loops of Henle of some nephrons

Residual volume (RV)

Amount of air that remains in the lungs after maximum exhalation.


any condition or parameter that slows or counteracts the flow of blood

respiratory bronchiole

Specific type of bronchiole that leads to alveolar sacs.

respiratory cycle

One sequence of inspiration and expiration.

respiratory epithelium

Ciliated lining of much of the conducting zone that is specialized to remove debris and pathogens, and produce mucus.

respiratory membrane

Alveolar and capillary wall together, which form an air-blood barrier that facilitates the simple diffusion of gases.

respiratory pump

increase in the volume of the thorax during inhalation that decreases air pressure, enabling venous blood to flow into the thoracic region, then exhalation increases pressure, moving blood into the atria

respiratory rate

Total number of breaths taken each minute.

Respiratory volume

Varying amounts of air within the lung at a given time.

respiratory zone

Includes structures of the respiratory system that are directly involved in gas exchange.

reticular lamina

A matrix containing collagen and elastin secreted by connective tissue; a component of the basement membrane.

reticular layer

Deeper layer of the dermis; it has a reticulated appearance due to the presence of abundant collagen and elastin fibers/

reticuloendothelial cells

(also, Kupffer cell) phagocyte in hepatic sinusoids that filters out material from venous blood from the alimentary canal

right atrioventricular valve

(also, tricuspid valve) valve located between the right atrium and ventricle; consists of three flaps of tissue

S phase

Stage of the cell cycle during which DNA replication occurs.

semilunar valves

valves located at the base of the pulmonary trunk and at the base of the aorta


(plural = septa) walls or partitions that divide the heart into chambers

septum primum

flap of tissue in the fetus that covers the foramen ovale within a few seconds after birth

serous glands

A group of cells within the serous membrane that secrete a lubricating substance onto the surface.

short-chain fatty acids

a metabolite that's produced by gut microbiota as a result of dietary fiber fermentation


changes in one's health that can be observed or measured objectively (eg. change in body temperature)

simple columnar epithelium

Tissue that consists of a single layer of column-like cells; promotes secretion and absorption in tissues and organs.

simple cuboidal epithelium

Tissue that consists of a single layer of cube-shaped cells; promotes secretion and absorption in ducts and tubules.

simple squamous epithelium

Tissue that consists of a single layer of flat scale-like cells; promotes diffusion and filtration across surface.

sinusoid capillary

rarest type of capillary, which has extremely large intercellular gaps in the basement membrane in addition to clefts and fenestrations; found in areas such as the bone marrow and liver where passage of large molecules occurs

sister chromatid

One of a pair of identical chromosomes, formed during DNA replication.

skeletal muscle pump

effect on increasing blood pressure within veins by compression of the vessel caused by the contraction of nearby skeletal muscle

small cardiac vein

parallels the right coronary artery and drains blood from the posterior surfaces of the right atrium and ventricle; drains into the great cardiac vein

somatic cells

All cells of the body excluding gamete cells.


blood pressure cuff attached to a device that measures blood pressure


chemicals with dyes are added to tissues and attach to cellular components based on their chemical characteristic (e.g. acidic, basic, hydrophobic)

stem cell

Cell that is oligo-, multi-, or pleuripotent that has the ability to produce additional stem cells rather than becoming further specialized.

stratified columnar epithelium

Tissue that consists of two or more layers of column-like cells, contains glands and is found in some ducts.

Stratified cuboidal epithelium

Tissue that consists of two or more layers of cube-shaped cells, found in some ducts.

stratified squamous epithelium

Tissue that consists of multiple layers of cells with the most apical being flat scale-like cells; protects surfaces from abrasion.

stratum basale

Deepest layer of the epidermis, made of epidermal stem cells.

stratum corneum

Most superficial layer of the epidermis.

stratum granulosum

Most superficial layer of the epidermis.

stratum lucidum

Layer of the epidermis between the stratum granulosum and stratum corneum, found only in thick skin covering the palms, soles of the feet, and digits.

stratum spinosum

Layer of the epidermis superficial to the stratum basale, characterized by the presence of desmosomes.

stroke volume

amount of blood ejected from the ventricle with each cardiac cycle


(plural = sulci) fat-filled groove visible on the surface of the heart; coronary vessels are also located in these areas


bacterial or viral proteins that can cause an excessive inflammatory response

superior vena cava

large systemic vein that returns blood to the heart from the superior portion of the body


changes in health which are subjectively felt and can not be objectively measured (eg. feeling nauseous)

systemic circuits

blood flow to and from virtually all of the tissues of the body

systemic edema

increased fluid retention in the interstitial spaces and cells of the body; can be seen as swelling over large areas of the body, particularly the lower extremities


a part of the heart cycle; contraction of the heart ventricles that ejects blood out of the heart

systolic failure

The left ventricle is unable to contract strongly enough during systole. As a result, not enough blood leaves the heart to nourish the rest of the body

systolic pressure

larger number recorded when measuring arterial blood pressure; represents the maximum value following ventricular contraction


abnormally high heart rate. In a resting adult, it is >100 beats per minute


rapid and shallow breathing; respiratory rate is >21 breaths per minute in adults


Final stage of mitosis (and meiosis), preceding cytokinesis, characterized by the formation of two new daughter nuclei.

Thoracic wall compliance

Ability of the thoracic wall to stretch while under pressure.

thoroughfare channel

continuation of the metarteriole that enables blood to bypass a capillary bed and flow directly into a venule, creating a vascular shunt

Tidal volume (TV)

Amount of air that normally enters the lungs during quiet breathing.

tight junctions

Forms an impermeable barrier between cells.

Total dead space

Sum of the anatomical dead space and alveolar dead space.

total lung capacity (TLC)

Total amount of air that can be held in the lungs; sum of TV, ERV, IRV, and RV.


Embryonic cells that have the ability to differentiate into any type of cell and organ in the body.

trabeculae carneae

ridges of muscle covered by endocardium located in the ventricles


Tube composed of cartilaginous rings and supporting tissue that connects the lung bronchi and the larynx; provides a route for air to enter and exit the lung.

trachealis muscle

Smooth muscle located in the fibroelastic membrane of the trachea.

transcription factors

One of the proteins that regulate the transcription of genes.

Transfusion medicine


transitional epithelium

Form of stratified epithelium found in the urinary tract, characterized by an apical layer of cells that change shape in response to the presence of urine.

Transpulmonary pressure

Pressure difference between the intrapleural and intra-alveolar pressures.

tricuspid valves

term used most often in clinical settings for the right atrioventricular valve


The most common of the three basic classes of lipids and the main form fat takes in both diet and the human body. A triacylglycerol is made up of three molecules of fatty acids and one molecule of glycerol.


an infectious bacterial disease (usually caused by Mycobacterium tuberculosis bacteria) that generally affects the lungs, but can also affect other parts of the body

Tumor suppressor

Segment of DNA that codes for regulator proteins that prevent the cell from undergoing uncontrolled division.


abnormal and excessive growth of cells, creating a mass of tissue

tunica externa

(also, tunica adventitia) outermost layer or tunic of a vessel (except capillaries)

tunica intima

(also, tunica interna) innermost lining or tunic of a vessel

tunica media

middle layer or tunic of a vessel (except capillaries)


type of fluid flow in which fluid undergoes irregular fluctuations and mixing


sounds like a ringing akin to striking a typmani drum. indicative of a lot of air trapped in a hollow vessel

type I alveolar cells

Squamous epithelial cells that are the major cell type in the alveolar wall; highly permeable to gases.

type II alveolar cells

Cuboidal epithelial cells that are the minor cell type in the alveolar wall; secrete pulmonary surfactant.


Describes the condition of being committed to a single specialized cell type.


transports urine from the bladder to the outside environment


in the cardiovascular system, a specialized structure located within the heart or vessels that ensures one-way flow of blood

vasa vasorum

small blood vessels located within the walls or tunics of larger vessels that supply nourishment to and remove wastes from the cells of the vessels

vascular shunt

continuation of the metarteriole and thoroughfare channel that allows blood to bypass the capillary beds to flow directly from the arterial to the venous circulation

vascular tone

contractile state of smooth muscle in a blood vessel


constriction of the smooth muscle of a blood vessel, resulting in a decreased vascular diameter


relaxation of the smooth muscle in the wall of a blood vessel, resulting in an increased vascular diameter


irregular, pulsating flow of blood through capillaries and related structures


blood vessel that conducts blood toward the heart

Vena cava

large vein that brings deoxygenated blood from the organs in the body back to the heart

venous reserve

volume of blood contained within systemic veins in the integument, bone marrow, and liver that can be returned to the heart for circulation, if needed

ventral respiratory group (VRG)

Region of the medulla oblongata that stimulates the contraction of the accessory muscles involved in respiration to induce forced inspiration and expiration.


one of the primary pumping chambers of the heart located in the lower portion of the heart; the left ventricle is the major pumping chamber on the lower left side of the heart that ejects blood into the systemic circuit via the aorta and receives blood from the left atrium; the right ventricle is the major pumping chamber on the lower right side of the heart that ejects blood into the pulmonary circuit via the pulmonary trunk and receives blood from the right atrium


small vessel leading from the capillaries to veins

visceral pleura

innermost layer of the pleura that is superficial to the lungs and extends into the lung fissures


thickness of fluids that affects their ability to flow

Vital capacity (VC)

Sum of TV, ERV, and IRV, which is all the volumes that participate in gas exchange.


skin condition in which Melanocytes in certain areas lose the ability to produce melanin, possibly due an autoimmune reaction that leads to loss of color in patches.


vascular smooth muscle cells


continuous, coarse, whistling sound produced in a narrowed or obstructed airway causing an increase airflow velocity


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