BIOL204 Lecture 6: Gastrointestinal System
Document Summary
Why do we eat: energy/cellular processes (converted in to atp, building blocks, growth and development, tissues repair. Digestive tract or elementary canal: digestive tract also called gastrointestinal (gi) tract or alimentary canal. Is a muscular tube: extends from oral cavity to anus, passes through pharynx, oesophagus, stomach, and small and large intestines. H2o absorption (very little chemical absorption: ascending, transverse and descending colon, sigmoid colon frames the small intestine, rectum: Is straight portion ending at anal canal: storage of faeces before passing out: anus, faeces leave the body (defecation). Need to know the function, label, loacation and how they work. Accessory structures: aid digestion, have other functions as well, liver produces plasma proteins & bile, pancreas secretes hormones & digestive enzymes, gall bladder concentrates & stores bile. Oral cavity saliva: 99. 4% water, 0. 6% includes, electrolytes (na+, cl-, and hco3-, buffers, glycoproteins (mucins, antibodies, enzymes, waste products.
