Goals: -Vitamins! -Role of accessory organs -Urinary system anatomy
Vitamin absorption in the intestinal tract Modified from Said, Vitamins are small molecules that cannot be synthesized by humans, required for physiological properties -Water soluble vitamins are commonly absorbed via transport proteins -Vitamin C - Na+ mediated carrier protein interacts with SVCT-1(sodium dependent vitamin c transporter) protein which absorbs ascorbic acid -Vitamin C members act as cofactors with enzymes that mediate collagen synthesis, tyrosine metabolism, and reduction of metal ions -Fat soluble vitamins (A, D, E, K) absorption mechanisms are less well known, may be carrier protein mediated or may be via diffusion (Harrison, 2005)
Hormones coordinate digestion - produced by the duodenum Gastrin Secretin Gastric inhibitory peptide Chollcysto kinin Vasoactive intestinal peptide
Cephalic phase of digestion
Gastric phase of digestion
Intestinal phase of digestion
The liver and pancreas produce bile and enzymes that neutralize stomach acid and digest food
The liver is very large, involved in 200+ functions
Bile is produced by the liver, stored in the bile duct, digests fats
The pancreas has an exocrine function, producing digestive enzymes and buffers to neutralize stomach acid
Acini pancreatic cells are exocrine cells
Mechanisms of hunger/appetite - CH 22
Urinary system Kidneys Functions to: -Adjust blood volume/pressure -Regulate salt concentrations -Stabalize pH -Conserve valuable nutrients -Eliminate wastes
The kidneys are retroperotineal organs
Internal anatomy of the kidney
Nephrons are the functional units of the kidney -Tubes of epithelium -Are selectively permeable to various substances -Concentrate wastes in blood, recover valuable components (such as glucose)
Anatomy of the bladder -Predominantly smooth muscle -Collects urine from the kidneys (via the ureters) -Stores urine until release
The urinary system is sexually dimorphic - Urethra is longer in men, passes prostate gland