5. The Digestive System Flashcards
how long is the GI tract
4.5 metres long
what are the 4 basic processes of the digestive system:
- digestion- breakdown of food
- absorption- transport of food into bloodstream
- motility- peristaltic activity of muscle propelling food along GI tract
- secretion- transport of digestive fluids into GI tract
name the accessory glands of the digestive system
pancreas
liver
gall bladder
salivary gland
what are the 5 components of the lumen
mucosa, submucosa, muscularis, serosa, nerve plexus
what does the submucosa consist of
connective tissue
blood
lymphatic vessels
what does the serosa consist of
connective tissue
protective layer
what does exocrine mean
secretion of enzymes into a duct directed at a target
what does endocrine mean
secretion of hormones into the bloodstream
how often is the mucus membrane replaced in an adult
every 5 days
what nervous system stimulates saliva response
the autonomic nervous system
what enzymes are found in saliva
salivary alpha-amylase and lingual lipase
name 3 other functions of saliva
lubrication
antibiotic action (lysozyme)
cleans teeth
what does the oesophagus connect
the pharynx to the stomach
how does heartburn occur
Backflow of upper and lower esophageal sphincters
what types of muscle are found in the oesophagus
upper 1/3 skeletal muscle
lower 2/3 smooth muscle
what is the function of parietal cells
secrete hydrochloric acid
what is the function of chief cells
secrete pepsinogen
what is pepsinogen
a zymogen of pepsin
parietal cells also secrete intrinsic factor, what is this
a glycoprotein required for the absorption of vitamin b12 in the ileum
what is the function of rennin
coagulates milk
what are the 4 regions of the stomach
fundus
body
antrum
pyloris
stomach is lined with gastric pits containing what cells
neck cells
chief cells
parietal cells
what is the function of neck cells
produce mucus, found at the top of the mucus pit
what hormone triggers the release of pepsinogen and HCL
gastrin
