BIO 211 Lecture Notes - Lecture 27: Gastric Acid, Muscular Layer, Gastric Glands
1 Dec 2020
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Document Summary
Gastric juice has a high concentration of hydrochloric acid. Parietal cells produce hcl and contain carbonic anhydrase (cah) Co2 + h2o h2co3 hco3. H+ is pumped into gastric gland lumen by h+- k+ atpase pump. Antiporter uses atp to pump h+ out and k+ in. Exchanged for cl- (chloride shift) from blood plasma. Cl- (chloride ion) pumped into the lumen of gastric gland to join h+ forming hcl. Gastric lipase and lingual lipase play a minor role in digesting dietary fats. Digests 10%-15% of dietary fats in the stomach. Intrinsic factor a glycoprotein secreted by parietal cells. Essential to absorption of vitamin b12 by the small intestine. Binds vitamin b12 and intestinal cells absorb this complex by receptor-mediated endocytosis. Vitamin b12 is needed to synthesize rbcs/hemoglobin and involved in dna synthesis in cells. Prevents pernicious anemia (production of large immature non functioning rbcs) Secretion of intrinsic factor is the only indispensable function of the stomach.
