PHS 4300 Lecture Notes - Lecture 8: Indigestion, Gastrin, Tachypnea
Document Summary
Process of taking food into the digestive tract. Mechanical movement of food through the gi tract. Peristalsis involuntary, alternate waves of contraction and relaxation of muscles. Chewing, mixing with saliva using the tongue, churning food in the stomach. Due to the action of secreted enzymes; begins in the mouth, completed in the small intestines. Expulsion of indigestible material (feces) or lymph; primarily in the small intestine: basic functional concepts. Lu(cid:373)e(cid:374) o gi tra(cid:272)t is (cid:858)outside(cid:859) the (cid:271)ody conditions in lumen for digestion. There are as many neurons in the gut as there are in the spinal cord. Job to respond to stimulation in the gut (enteric nervous system) Mechanoreceptors and chemoreceptors located in the wall of the gi tract organs. Short reflexes local (enteric) response to gi tract stimuli. Long reflexes cns centers and extrinsic autonomic nerves. Stimuli can come from within or from outside the gi tract.