BIOL 2420 Lecture Notes - Lecture 30: Hyperammonemia, Intestinal Parasite Infection, Waterborne Diseases
5 Apr 2017
School
Department
Course
Professor
Document Summary
Diarrhea is not a simple disease with a simple explanation. Multiple possible causes which may not be mutually exclusive. Refers to elevated ammonia levels in the circulatory system. In the brain ammonia causes: cell swelling (bursting) of astrocytes, prolonged activation of postsynaptic neurons by glutamate due to inhibition of re-uptake, activation of postsynaptic nmda receptors -> ca2+ in ux -> cell death. Hyperammonemia effects felt as low as 100um. Inborn liver failure (compromised ammonia detoxi cation by ornithine-urea cycle) Secondary acquired damage of liver (ex. excessive alcohol consumption, hepatitis c) Bacterial break-down of urea and amino acids in colon; leakage of gut ammonia into portal vein (250 mmol/d) Amino acids digest in small intestine by phosphate activated-glutaminase. To avoid massive in uxes of toxic ammonia the intestine must have a protective mechanism in place (not fully understood) Ranked #8 on the top 10 human parasites world-wide. Most common waterborne disease in north america.
