Large intestine Flashcards
1
Q
ileoceacal valve
A
ileal distension–> open
caecal distension –> close
2
Q
Motility
A
most intrinsic control via ENS
3
Q
Presence of undigested lipid
A
–> peptideYY release –> slow gastric emptying and peristalsis} ileal brake
4
Q
Salt absorption
A
ENaC channels; stimulated by aldosterone
5
Q
Chloride secretion
A
cAMP (chlorea and ecoli toxins increase) and Ca2+ (C.dif increases) –> Cl- in –> Na+ in -> H20 in
6
Q
K+ secretion
A
Lumen often negative due to Cl- –> passive K+
Balance determined by plasma K+, aldosterone and cAMP
7
Q
Defecation
A
faeces –> rectum –> ^ pressure –> reflex relaxation internal anal sphincter–> urge defecate –> anal sampling –> external sphincter contracts –> sit/squat ^ rectosigmoid angle –> relax external sphincter and pelvic floor muscles
