Template:SN: Difference between revisions
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==Pathophysiology== | ==Pathophysiology== | ||
Vitamin B12 is an essential vitamin for humans and animals because we cannot synthesise it on our own. B12 is a cofactor in DNA synthesis and other important biochemical reactions. Vitamin B12 deficiency manifests as anaemia because hematopoetic stem cells in the bone marrow which are rapidly dividing need B12 for division and DNA production. This process is impaired leading to ineffective hematopoeisis. Vitamin B12 is also necessary for production of myelin which is an important component in the covering sheath of nerves. Deficiency results in improper nerve conduction due to nerve destabilisation. | |||
=== Physiology === | === Physiology === | ||
Vitamin B12 is also called cobalamin because it contains cobalt at the core of its structure. Dietary sources of vitamin B12 include meat, fish and eggs. When consumed through its dietary source, B12 is bound to protein till it enters the stomach. In the stomach, B12 is uncoupled from its carrier protein due to the presence of hydrochloric acid. It is then bound to gastric R binder, a glycoprotein secreted by the salivary glands till it reaches the duodenum. In the duodenum and jejunum, the pancreatic enzymes digest the gastric R binder and cobalamin is bound to | |||
=== Pathogenesis === | === Pathogenesis === | ||
Revision as of 16:01, 22 June 2020
"sandbox:SN"
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief:
Overview
Pernicious anaemia (also called Addison's anemia) is a type of red blood cell disorder caused by impaired vitamin B12 metabolism. Vitamin B12 is primarily absorbed by the small intestine, after being bound to intrinsic factor secreted by parietal cells of gastric mucosa. When this process is disrupted by conditions like atrophic gastritis, celiac disease, small bowel resection etc, B12 deficiency ensues. Historically, this type of anaemia was called "pernicious" because it was harder to treat and most often resulted in death. Red blood cells in this type of anaemia are abnormally large, thus earning the name megaloblastic anaemia. Pernicious anaemia might be caused due to insufficient intake or poor absorption.
Pathophysiology
Vitamin B12 is an essential vitamin for humans and animals because we cannot synthesise it on our own. B12 is a cofactor in DNA synthesis and other important biochemical reactions. Vitamin B12 deficiency manifests as anaemia because hematopoetic stem cells in the bone marrow which are rapidly dividing need B12 for division and DNA production. This process is impaired leading to ineffective hematopoeisis. Vitamin B12 is also necessary for production of myelin which is an important component in the covering sheath of nerves. Deficiency results in improper nerve conduction due to nerve destabilisation.
Physiology
Vitamin B12 is also called cobalamin because it contains cobalt at the core of its structure. Dietary sources of vitamin B12 include meat, fish and eggs. When consumed through its dietary source, B12 is bound to protein till it enters the stomach. In the stomach, B12 is uncoupled from its carrier protein due to the presence of hydrochloric acid. It is then bound to gastric R binder, a glycoprotein secreted by the salivary glands till it reaches the duodenum. In the duodenum and jejunum, the pancreatic enzymes digest the gastric R binder and cobalamin is bound to