BIOLOGY 2A03 Lecture Notes - Lecture 59: Cerebral Cortex, Ketone Bodies, Lipoprotein Lipase
Document Summary
Large amounts of water needs to be secreted into gi tract for efficient nutrient digestions: water comes in the form of gastric/pancreatic juice, or bile. Volume of secreted water more than that of ingested water: most of it absorbed in small intestine; some in colon, very small volumes of water lost in feces so still have overall gain from ingested water. Stimuli = presence of food controls digestion via psns, sns, and enteric nervous system + gi hormones secreted by stomach and small intestine. Enteric nervous system: a semi-autonomic nervous system that has its own sensory neurons, interneurons, and motor neurons which innervate effector cells such as smooth muscle, endocrine cells, or exocrine cells (release substances to lumen) Cephalic phase control: conscious control of gi tract in response to smell/thought of food: influenced by consciousness: cerebral cortex. Enterogastrones: 4 gi hromones that are released by gi endocrine cells into blood.