GI 1 Flashcards
what Primary function of digestive system
absorption of nutrients, water and electrolytes from the external environment into the body’s internal environment
what is the digestive system central to
regulation and integration of metabolic processes throughout body
what is proper functioning of digestive system necessary for
whole-body homeostasis
what % of health care costs related to GI system
10%
where does digestive system extend from
mouth -> large intestine
15ft in live person
what is the GI tract
long tube with muscular walls lined by transporting and secretory epithelial (esophagus to end)
order of the digestive system
mouth - pharynx - esophagus - stomach - small int - large int - external environment
stomach to anus
the gut
digestion
mechanical and chemical breakdown of food primarily occurs in gut
what contributes to digestion
secretions from accessory glandular organs
salivary glands, liver, gallbladder, pancreas
GI tract is technically what
a continuation of external environment
where does digestion begin
in mouth with mastification and addition of saliva
what are three salivary glands in mouth
parotid, sublingual, submandibular
what are the 4 functions of salivary glands
- moisten and lubricate food
- salivary amylase partially digests polysaccharides
- dissolve some food molecules (taste)
- lysozyme kills bacteria
esophagus
passageway from mouth to stomach
what is the esophagus made of
top 1/3 skeletal muscle (voluntary) bottom 2/3 smooth muscle
what sphincter are connected to esophagus
upper and lower esophageal sphincters
what does the esophagus do
moves food via perstaltic waves (just motility no digestion)
where does digestion continue after esophagus
stomach
what happens in stomach
mixes food with acid and enzymes to create chyme (lots of mechanical)