{"id":5389,"date":"2025-12-08T23:10:06","date_gmt":"2025-12-09T04:10:06","guid":{"rendered":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/?post_type=chapter&#038;p=5389"},"modified":"2026-01-12T18:38:38","modified_gmt":"2026-01-12T23:38:38","slug":"liver-function-in-hemoglobin-breakdown-and-bilirubin-metabolism","status":"web-only","type":"chapter","link":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/chapter\/liver-function-in-hemoglobin-breakdown-and-bilirubin-metabolism\/","title":{"raw":"10p15  Liver Function in Hemoglobin Breakdown and Bilirubin Metabolism","rendered":"10p15  Liver Function in Hemoglobin Breakdown and Bilirubin Metabolism"},"content":{"raw":"<h1><strong>Review:\u00a0 Red Blood Cell (RBC) Lifecycle<\/strong><\/h1>\r\n<ul>\r\n \t<li>RBCs last about\u00a0<strong>120 days<\/strong>.<\/li>\r\n \t<li>Macrophages\u00a0<strong>phagocytose<\/strong>\u00a0(engulf and destroy) old RBCs.<\/li>\r\n \t<li>The process of recycling approximately\u00a0<strong>1 to 3 million RBCs per second<\/strong>.<\/li>\r\n<\/ul>\r\n<h1><strong>Review:\u00a0 Hemoglobin Structure<\/strong><\/h1>\r\n<ul>\r\n \t<li>RBCs contain\u00a0<strong>hemoglobin<\/strong>, which lacks organelles and a nucleus.<\/li>\r\n \t<li>Hemoglobin is composed of:\r\n<ul>\r\n \t<li><strong>Four polypeptides<\/strong>:\r\n<ul>\r\n \t<li><strong>2 alpha chains<\/strong>.<\/li>\r\n \t<li><strong>2 beta chains<\/strong>.<\/li>\r\n<\/ul>\r\n<\/li>\r\n \t<li><strong>Four heme groups<\/strong>:\r\n<ul>\r\n \t<li>Each heme contains an\u00a0<strong>iron atom<\/strong>.<\/li>\r\n \t<li>Iron gives blood its characteristic\u00a0<strong>reddish hue<\/strong>.<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n<h1><strong>1.\u00a0 Recycling of Hemoglobin<\/strong><\/h1>\r\n<strong>Breakdown<\/strong>\r\n<ul>\r\n \t<li><strong>Globins<\/strong> (the protein part) are degraded into <strong>amino acids<\/strong>.<\/li>\r\n \t<li><strong>Heme<\/strong>:\r\n<ul>\r\n \t<li><strong>Iron<\/strong>:\r\n<ul>\r\n \t<li>Removed from heme.<\/li>\r\n \t<li>Stored or reused to make new hemoglobin.<\/li>\r\n<\/ul>\r\n<\/li>\r\n \t<li><strong>Remaining heme<\/strong>:\r\n<ul>\r\n \t<li>Converted to\u00a0<strong>bilirubin<\/strong>.<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n<h1><strong>2.\u00a0 Bilirubin Formation<\/strong><\/h1>\r\n<ul>\r\n \t<li>Bilirubin initially appears as <strong>unconjugated bilirubin<\/strong>:\r\n<ul>\r\n \t<li><strong>Not water-soluble<\/strong>.<\/li>\r\n \t<li>Toxic if accumulated in blood.<\/li>\r\n<\/ul>\r\n<\/li>\r\n \t<li>Liver cells <strong>conjugate<\/strong> bilirubin:\r\n<ul>\r\n \t<li>Make it\u00a0<strong>water-soluble<\/strong>.<\/li>\r\n \t<li>Facilitate excretion into the\u00a0<strong>bile<\/strong>.<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n<h2><strong>3.\u00a0 Excretion<\/strong><\/h2>\r\n<ul>\r\n \t<li>Bilirubin is secreted into\u00a0<strong>bile<\/strong>, enters the\u00a0<strong>intestine<\/strong>, and aids\u00a0<strong>fat emulsification<\/strong>.<\/li>\r\n \t<li>In the intestine, bilirubin is processed and eventually excreted via\u00a0<strong>feces<\/strong>.<\/li>\r\n<\/ul>\r\n<h1><strong>Impaired Bilirubin Processing and Jaundice<\/strong><\/h1>\r\n<ul>\r\n \t<li>Excessive\u00a0<strong>hemolysis<\/strong>\u00a0(destruction of RBCs) produces more bilirubin than the liver can handle.<\/li>\r\n \t<li>Elevated bilirubin\u00a0<strong>builds up in blood<\/strong>, leading to\u00a0<strong>jaundice<\/strong>:\r\n<ul>\r\n \t<li>Yellowish discoloration of\u00a0<strong>skin<\/strong>\u00a0and\u00a0<strong>sclera<\/strong>\u00a0(white part of eyes).<\/li>\r\n<\/ul>\r\n<\/li>\r\n \t<li>This condition indicates\u00a0<strong>liver dysfunction<\/strong>\u00a0or\u00a0<strong>excessive RBC breakdown<\/strong>.<\/li>\r\n<\/ul>\r\n<h1><strong>Summary<\/strong><\/h1>\r\n<ul>\r\n \t<li>Normal RBC breakdown involves hemoglobin recycling and bilirubin excretion.<\/li>\r\n \t<li>Disruptions lead to\u00a0<strong>jaundice<\/strong>, signaling potential liver or hematologic issues.<\/li>\r\n \t<li>The liver plays a crucial role in processing waste products from blood.<\/li>\r\n<\/ul>","rendered":"<h1><strong>Review:\u00a0 Red Blood Cell (RBC) Lifecycle<\/strong><\/h1>\n<ul>\n<li>RBCs last about\u00a0<strong>120 days<\/strong>.<\/li>\n<li>Macrophages\u00a0<strong>phagocytose<\/strong>\u00a0(engulf and destroy) old RBCs.<\/li>\n<li>The process of recycling approximately\u00a0<strong>1 to 3 million RBCs per second<\/strong>.<\/li>\n<\/ul>\n<h1><strong>Review:\u00a0 Hemoglobin Structure<\/strong><\/h1>\n<ul>\n<li>RBCs contain\u00a0<strong>hemoglobin<\/strong>, which lacks organelles and a nucleus.<\/li>\n<li>Hemoglobin is composed of:\n<ul>\n<li><strong>Four polypeptides<\/strong>:\n<ul>\n<li><strong>2 alpha chains<\/strong>.<\/li>\n<li><strong>2 beta chains<\/strong>.<\/li>\n<\/ul>\n<\/li>\n<li><strong>Four heme groups<\/strong>:\n<ul>\n<li>Each heme contains an\u00a0<strong>iron atom<\/strong>.<\/li>\n<li>Iron gives blood its characteristic\u00a0<strong>reddish hue<\/strong>.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h1><strong>1.\u00a0 Recycling of Hemoglobin<\/strong><\/h1>\n<p><strong>Breakdown<\/strong><\/p>\n<ul>\n<li><strong>Globins<\/strong> (the protein part) are degraded into <strong>amino acids<\/strong>.<\/li>\n<li><strong>Heme<\/strong>:\n<ul>\n<li><strong>Iron<\/strong>:\n<ul>\n<li>Removed from heme.<\/li>\n<li>Stored or reused to make new hemoglobin.<\/li>\n<\/ul>\n<\/li>\n<li><strong>Remaining heme<\/strong>:\n<ul>\n<li>Converted to\u00a0<strong>bilirubin<\/strong>.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h1><strong>2.\u00a0 Bilirubin Formation<\/strong><\/h1>\n<ul>\n<li>Bilirubin initially appears as <strong>unconjugated bilirubin<\/strong>:\n<ul>\n<li><strong>Not water-soluble<\/strong>.<\/li>\n<li>Toxic if accumulated in blood.<\/li>\n<\/ul>\n<\/li>\n<li>Liver cells <strong>conjugate<\/strong> bilirubin:\n<ul>\n<li>Make it\u00a0<strong>water-soluble<\/strong>.<\/li>\n<li>Facilitate excretion into the\u00a0<strong>bile<\/strong>.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h2><strong>3.\u00a0 Excretion<\/strong><\/h2>\n<ul>\n<li>Bilirubin is secreted into\u00a0<strong>bile<\/strong>, enters the\u00a0<strong>intestine<\/strong>, and aids\u00a0<strong>fat emulsification<\/strong>.<\/li>\n<li>In the intestine, bilirubin is processed and eventually excreted via\u00a0<strong>feces<\/strong>.<\/li>\n<\/ul>\n<h1><strong>Impaired Bilirubin Processing and Jaundice<\/strong><\/h1>\n<ul>\n<li>Excessive\u00a0<strong>hemolysis<\/strong>\u00a0(destruction of RBCs) produces more bilirubin than the liver can handle.<\/li>\n<li>Elevated bilirubin\u00a0<strong>builds up in blood<\/strong>, leading to\u00a0<strong>jaundice<\/strong>:\n<ul>\n<li>Yellowish discoloration of\u00a0<strong>skin<\/strong>\u00a0and\u00a0<strong>sclera<\/strong>\u00a0(white part of eyes).<\/li>\n<\/ul>\n<\/li>\n<li>This condition indicates\u00a0<strong>liver dysfunction<\/strong>\u00a0or\u00a0<strong>excessive RBC breakdown<\/strong>.<\/li>\n<\/ul>\n<h1><strong>Summary<\/strong><\/h1>\n<ul>\n<li>Normal RBC breakdown involves hemoglobin recycling and bilirubin excretion.<\/li>\n<li>Disruptions lead to\u00a0<strong>jaundice<\/strong>, signaling potential liver or hematologic issues.<\/li>\n<li>The liver plays a crucial role in processing waste products from blood.<\/li>\n<\/ul>\n","protected":false},"author":1370,"menu_order":18,"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-5389","chapter","type-chapter","status-web-only","hentry","contributor-zoe-soon","license-cc-by-nc-sa"],"part":67,"_links":{"self":[{"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/pressbooks\/v2\/chapters\/5389","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":3,"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/pressbooks\/v2\/chapters\/5389\/revisions"}],"predecessor-version":[{"id":5392,"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/pressbooks\/v2\/chapters\/5389\/revisions\/5392"}],"part":[{"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/pressbooks\/v2\/parts\/67"}],"metadata":[{"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/pressbooks\/v2\/chapters\/5389\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/wp\/v2\/media?parent=5389"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/pressbooks\/v2\/chapter-type?post=5389"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/wp\/v2\/contributor?post=5389"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/wp\/v2\/license?post=5389"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}