BIOL 1080 Study Guide - Midterm Guide: Chylomicron, Hydrophile, Lactase
Document Summary
The gi tract represents a vast surface are of the body that is exposed to the external environment. Sees not only our food, but potentially toxic substances and infectious agents. Mechanisms unique to deal with this: sense and expel noxious substances vomit, diarrhea, pe(cid:272)ialized populatio(cid:374) of t (cid:272)ells lo(cid:272)alized to i(cid:374)testi(cid:374)al (cid:373)u(cid:272)osa (cid:894)e. g. peye(cid:396)(cid:859)s. Sphincters keep the food from glowing backwards. Oral cavity esophagus stomach small intestine colon (large intestine) rectum. About 28ft long folded a lot in the abdominal cavity. Has large luminal surface area of between 200-400 square meters due to lots of villi/microvilli. Highly variable transit time for an ingested meal with a marker (total 20-80 hrs: 5-8hrs in the stomach and small intestine, the rest in the colon. Houses resident gut microbiome (bacteria) and protects against pathogenic microbes that enter/reside in the tract. Has its own intrinsic nervous system to control and coordinate all its functioning. Secretion saliva, mucous, antibodies, digestive enzymes, bile, bicarbonate.
