L21 - GI Tract Structure Flashcards
What is the GI system?
A network of organs and specialised cells - enable you to transform the food you eat into the energy and nutrients required for life
What are the different parts of the GI tract?
- mouth
- oesophagus
- stomach
- small intestine
- large intestine
- anus
What are the accessory organs in the GI tract?
- salivary glands
- liver
- gallblader
- pancreas
What is the mesentery?
Membranous tissue that surround organs of the GI tract
What does the mesentery do?
- holds intestines in place
- provides blood vessels and lymphatics
What are the different parts of the mouth?
- teeth
- tongue
- mucous membranes
- pharynx and epiglottis
What is the main function of the mouth?
To chew food
What is the pharyn and epiglottis and their function?
Muscular flaps in the throat
- prevents food travelling to the lungs
What is the oesophagus?
Tube like structure
What does the oesophagus do?
Involuntary movement of food bolus
- transports food bolus to the stomach
What does the stomach do?
- mixing
- protein digestion
- fat emulsification
What does the stomach contain?
- HCl
- pepsin
What are the different layers of the stomach wall?
- mucosa
- submucosa
- muscularis externa
- serosa
What are the different types of cell types in the stomach wall? And what do they secrete?
- mucous neck cell - mucus, protects lining
- parietal cells - HCl, intrinsic factor
- enterchromaffin-like cell - histamine
- chief cells - pepsin(ogen), gastric lipase
- D cells - somatostatin, inhibits acid
- G cells - gastrin, stimulates acid
What is the small intestine?
Longest part of the GI tract
- main site of absorption
- primary site of breakdown (CHO, proteins, fats)
What are the 3 section of the SI?
- duodenum
- jejunum
- illeum