Purpose of the Gut Flashcards
What are the broad functions of the mouth?
- Physically break down food
- Release initial digstive enzymes (amylase + lipase)
- Infection control
What are the broad functions of the oesophagus?
- Rapid transport of food through thorax
- Upper Oesophagus Sphincter prevents air entering GI tract
- Lower Oesophagus Sphincter helps prevent reflux into oesophagus
What are the broad functions of the stomach?
- Storage facility
- Produces chyme
- Infection control
- Secretes intrinsic factor (to activate Vit B12
What is chyme?
A fluid from the stomach that contains gastric secretions and partially digested food
How many muscular layers does the stomach have?
3
What are the broad fucntions of the duodenum?
- start of small intestine
- neutralises acidic chyme by HCO3 rich secretions
- Digestion
What is the broad function of the Jejunum/ Ileum?
- final digestion
- nutrient absorption
- water/ electrolyte absorption
- Bile recirculation
- B12 absorption
What are the broad functions of the large bowel?
- Final water absorption
- Temporary storage
- Final electrolyte absorption
Which part of the bowel absorbs the greatest overall water volume?
The small bowel
What is the main function of the rectum/anus?
Defaecation
How is the gut controlled?
- Autonomic nervous system
- Enteric nervous system
Which part of the autonomic nervous sytem controls the gut? Which nerves are involved?
- Parasympathetic
- Vagus Nerve
- Pelvic Spanchic nerves (S2-4)
How does the sympathetic nervous system control the gut?
- Sympathetic turns OFF digestion
- Innervates gut T5-L2
- Forms abdominopelvic presynaptic splanchnic nerves
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What are the 3 divisions of the presynaptic splanchinic nerves?
- Greater ( T5-9)
- Lesser (T10-11)
- Least (T12)
What is the enteric nervous system?
A division of the nervous system that extends oesophagus → anus
