{"id":4864,"date":"2025-11-22T17:31:46","date_gmt":"2025-11-22T22:31:46","guid":{"rendered":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/?post_type=chapter&p=4864"},"modified":"2025-12-07T23:10:52","modified_gmt":"2025-12-08T04:10:52","slug":"kidney-function","status":"web-only","type":"chapter","link":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/chapter\/kidney-function\/","title":{"raw":"8p2 Kidney Function","rendered":"8p2 Kidney Function"},"content":{"raw":"

Kidney's Roles include:<\/strong><\/h1>\r\nFiltering Blood and constantly maintaining Salt-Water Balance and pH of the Blood:<\/strong>\r\n

Physiology Overview:<\/h1>\r\n
    \r\n \t
  1. Blood enters via the afferent arteriole<\/strong>\u00a0into the\u00a0glomerulus<\/strong>\u2014a network of\u00a0leaky capillaries<\/strong>.<\/li>\r\n \t
  2. Filtrate is collected in the\u00a0Bowman\u2019s capsule<\/strong>; normally, about\u00a0142 liters\/day<\/strong>\u00a0of filtrate is produced, but only\u00a02 liters\/day<\/strong>\u00a0is normally excreted as urine.<\/li>\r\n \t
  3. The kidneys\u00a0reabsorb most of the filtrate<\/strong>, removing waste<\/strong> while conserving water, nutrients,<\/strong> and electrolytes.<\/strong><\/li>\r\n<\/ol>\r\n

    Detailed Steps of Nephron Function:<\/h1>\r\n
      \r\n \t
    1. The renal artery<\/strong> brings oxygenated blood, dividing into arterioles to distributes blood throughout the kidney.<\/li>\r\n \t
    2. Each afferent arteriole<\/strong> brings blood into a glomerular capillary<\/strong> clustered inside a Bowman\u2019s (renal) corpuscle<\/strong>.<\/li>\r\n \t
    3. The hydrostatic pressure of afferent arterioles<\/strong> is high (~55mmHg), and the glomerular capillaries<\/strong> are very leaky (sinusoid capillaries), meaning that blood filtration occurs at each glomerulus.<\/li>\r\n \t
    4. The Bowman\u2019s capsule<\/strong> captures the filtrate<\/strong>, which consists of water and small solutes that filter out leaving blood plasma.<\/li>\r\n \t
    5. The solutes contain nitrogenous wastes<\/strong> (urea, uric acid and creatinine) as well as excess salts (e.g. NaCl), excess H+ (acid). This allows the kidney to perform its main role of constantly maintaining water-salt<\/strong> balance<\/strong> and pH<\/strong> of the blood<\/strong>.<\/li>\r\n \t
    6. The filtrate<\/strong> continues through nephron tubule and much of the water<\/strong> as well as small nutrients<\/strong> (e.g., amino<\/strong> acids<\/strong>, glucose<\/strong>) are reabsorbed back into the bloodstream of the surrounding peritubular capillaries.<\/li>\r\n \t
    7. The filtrate passes down the collecting duct of the nephron into the minor calyces, the major calyces, the renal pelvis and down the ureters to the bladder.\u00a0 Urine contains nitrogenous wastes (urea, uric acid, creatinine), excess salt, excess acid (H+), drug & hormone breakdown products, and excess water.<\/li>\r\n<\/ol>\r\n
        \r\n \t
      1. \r\n
          \r\n \t
        1. \r\n\r\n[caption id=\"attachment_1823\" align=\"alignnone\" width=\"1975\"]\"\"<\/a> Internal Structures of the Left Kidney[\/caption]<\/li>\r\n \t
        2. \r\n\r\n[caption id=\"attachment_1825\" align=\"alignnone\" width=\"1971\"]\"\"<\/a> Blood Flow in the Kidney[\/caption]<\/li>\r\n \t
        3. \"\"<\/a><\/li>\r\n<\/ol>\r\n<\/li>\r\n<\/ol>","rendered":"

          Kidney’s Roles include:<\/strong><\/h1>\n

          Filtering Blood and constantly maintaining Salt-Water Balance and pH of the Blood:<\/strong><\/p>\n

          Physiology Overview:<\/h1>\n
            \n
          1. Blood enters via the afferent arteriole<\/strong>\u00a0into the\u00a0glomerulus<\/strong>\u2014a network of\u00a0leaky capillaries<\/strong>.<\/li>\n
          2. Filtrate is collected in the\u00a0Bowman\u2019s capsule<\/strong>; normally, about\u00a0142 liters\/day<\/strong>\u00a0of filtrate is produced, but only\u00a02 liters\/day<\/strong>\u00a0is normally excreted as urine.<\/li>\n
          3. The kidneys\u00a0reabsorb most of the filtrate<\/strong>, removing waste<\/strong> while conserving water, nutrients,<\/strong> and electrolytes.<\/strong><\/li>\n<\/ol>\n

            Detailed Steps of Nephron Function:<\/h1>\n
              \n
            1. The renal artery<\/strong> brings oxygenated blood, dividing into arterioles to distributes blood throughout the kidney.<\/li>\n
            2. Each afferent arteriole<\/strong> brings blood into a glomerular capillary<\/strong> clustered inside a Bowman\u2019s (renal) corpuscle<\/strong>.<\/li>\n
            3. The hydrostatic pressure of afferent arterioles<\/strong> is high (~55mmHg), and the glomerular capillaries<\/strong> are very leaky (sinusoid capillaries), meaning that blood filtration occurs at each glomerulus.<\/li>\n
            4. The Bowman\u2019s capsule<\/strong> captures the filtrate<\/strong>, which consists of water and small solutes that filter out leaving blood plasma.<\/li>\n
            5. The solutes contain nitrogenous wastes<\/strong> (urea, uric acid and creatinine) as well as excess salts (e.g. NaCl), excess H+ (acid). This allows the kidney to perform its main role of constantly maintaining water-salt<\/strong> balance<\/strong> and pH<\/strong> of the blood<\/strong>.<\/li>\n
            6. The filtrate<\/strong> continues through nephron tubule and much of the water<\/strong> as well as small nutrients<\/strong> (e.g., amino<\/strong> acids<\/strong>, glucose<\/strong>) are reabsorbed back into the bloodstream of the surrounding peritubular capillaries.<\/li>\n
            7. The filtrate passes down the collecting duct of the nephron into the minor calyces, the major calyces, the renal pelvis and down the ureters to the bladder.\u00a0 Urine contains nitrogenous wastes (urea, uric acid, creatinine), excess salt, excess acid (H+), drug & hormone breakdown products, and excess water.<\/li>\n<\/ol>\n
                \n
              1. \n
                  \n
                1. \n
                  \"\"<\/a>
                  Internal Structures of the Left Kidney<\/figcaption><\/figure>\n<\/li>\n
                2. \n
                  \"\"<\/a>
                  Blood Flow in the Kidney<\/figcaption><\/figure>\n<\/li>\n
                3. \"\"<\/a><\/li>\n<\/ol>\n<\/li>\n<\/ol>\n","protected":false},"author":1370,"menu_order":5,"template":"","meta":{"pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":["zoe-soon"],"pb_section_license":"cc-by-nc-sa"},"chapter-type":[],"contributor":[60],"license":[57],"class_list":["post-4864","chapter","type-chapter","status-web-only","hentry","contributor-zoe-soon","license-cc-by-nc-sa"],"part":59,"_links":{"self":[{"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/pressbooks\/v2\/chapters\/4864","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/wp\/v2\/users\/1370"}],"version-history":[{"count":4,"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/pressbooks\/v2\/chapters\/4864\/revisions"}],"predecessor-version":[{"id":5262,"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/pressbooks\/v2\/chapters\/4864\/revisions\/5262"}],"part":[{"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/pressbooks\/v2\/parts\/59"}],"metadata":[{"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/pressbooks\/v2\/chapters\/4864\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/wp\/v2\/media?parent=4864"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/pressbooks\/v2\/chapter-type?post=4864"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/wp\/v2\/contributor?post=4864"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/wp\/v2\/license?post=4864"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}