Functions of LI Flashcards
What type of cell produce the mechanical digestion in the LI?
Smooth muscle
What are the 3 types of peristaltic waves in the LI?
Haustral chruning
Gastroilial reflex
Gastrocolic reflex
What is haustral churning?
Relaxed pouched filled from below by muscular contraction
What is the gastroiliac reflex?
When the stomach is full gastrin hormone causes the ileocecal sphincter to relax and the SI to empty and make room
What is the gastrocolic reflex?
When the stomach fails strong peristaltic waves move contents of transverse colon into the rectum
What hormone controls the gastroiliac reflex?
Gastrin
What enzymes are released in the LI for chemical digestion?
No enzymes just mucous
What is the effect of bacteria fermentation on undigested carbohydrates in the LI?
Breaks them down into CO2 and CH4
What is the effect of bacteria fermentation on undigested proteins in the LI?
Breaks them down into simpler proteins this produces an odour
What is the effect of bacteria fermentation on bilirubin?
Breaks it down into simpler proteins producing a colour
What electrolytes are absorbed by the LI?
Na+ and Cl-
After 3-10 hours 90% of water substance is removed from chyme, leading to the faeces being semisolid in the transverse colon?
Water
What is faeces made of?
Dead epithelial cells, undigested food (cellulose), bacteria (live and dead)
What relfex assist defection?
Gastrocolic
After the gastrocolic reflex moves the faeces into the rectum what occurs?
Stretch receptors signal and parasympathetic impulses cause muscles of the rectum to contract and the internal anal sphincter to relax.
