lecture 13 - large intestine Flashcards
what are the primaruy activities in the large intestine?
- active transport of sodium coupled with osmotic absorption of water
- microbes here are active int he production of vitamin K
progression of semi solid …. is …..
chyme is slow (5-10cm/hour)
what does parasympathetic activity do to the large intestine?
increases activity
mass movement occurs ….. a day in the form of ….
1-3 times per day in the form of peristaltic waves
what can the colon absorb?
amino acids, fatty acids, peptides
what is the main secretant in the large intestine and what is its function?
mucas which is a protectant and adherent
what happens when the colic wall is irritated?
water and electrolytes can be secreted which can cause diarrhoea
the digestion of some ….. such as …. occurrs in the large intestine
complex carbs such as cellulose
how does the digestion of complex carbs happen in the large intestine?
- fermentation by bacteria beta short chain fatty acids
- produce some vitamin K and vitamin B12
what is flatus and how much is produced a day?
- gas produced from fermentation by bacteria
- make 0.7-1 L a day and 400-700 ml is released per day
miicroorganisms convert …. to ….
waster to faeces
what does faeces consist of ?
- 75 % water
- 25 % bacteria, bacterial waste, roughage, bile pigments
The rectum is usually ….
empty
what passes matter back to the sigmoid colon
segmental contractions
what fills the rectum?
mass movement
