VI- Small and Large Intestine

Question 1

anatomical features of sm intestine

Answer 1

transverse folds/pilicae circulares + villi + microvilli make relatively large surface area for absorption

NO villi in lg intest

Question 2

absorptive enterocytes

Answer 2

@crypts of lieberkuhn for digest and absorb nutrients via enzyme-ases

Question 3

goblet cells

Answer 3

@crypts of lieberkuhn to secrete mucus

Question 4

secretory enterocytes

Answer 4

@ crypts of lieberkuhn for absorption via water layer of H2O and electrolytes

Question 5

brunner’s glands

Answer 5

@ duodenum to secrete mucus and bicarb to protect mucosa from acid

Question 6

regulation of brunner’s glands

Answer 6

stim by : chyme, ENS, CCK, secretin,
inhibited by: symps

Question 7

secretory colonocytes

Answer 7

for secreting H20 and electrolytes for excretion

Question 8

absorptive colonocytes

Answer 8

for absorbing H2O and electrolytes

Question 9

small intestine movements

Answer 9

higher segmentation rate/mixing so high pressure
-contractions stim by mechanical aka distension

Question 10

large intestine movements

Answer 10

lower segmentation rate than small,
-haustral shuttling/segmental contractions inc rate as get closer to sigmoid colon aka motility slowed down but absorption inc
-mass peristalsis to move toward rectum

Question 11

ileal brake

Answer 11

nutrients and distension of ileum impair gastric emptying thru ileogastric reflex of ENS
-involves GLP1 and peptide YY

Question 12

GLP1 function

Answer 12

dec motility in stomach
-comes from distal small intestine to target pancreas, stomach, small intest

Question 13

motilin function

Answer 13

inc SM contractions of upper GI and reg MMC
-promotility protein
-from duodenum and jejunum

Question 14

peptide YY function

Answer 14

to dec motility and dec pancreas secretions
-from ileum and colon to target pancreas, small intestine, stomach

Question 15

gastroileal reflex

Answer 15

distension of stomach triggers peristalsis in ileum and opening of Is to empy small into large intestine

Question 16

defecation components

Answer 16

passive distension of rectum until ENS initiates peristalsis wave in descending colon
-parasymps relax IAS and inc tone of EAS

Question 17

factors for bacterial growth

Answer 17

1. GI secretions
2. mucosal immunity
3. intestinal motility
4. pharmacological agents

Question 18

key functions of microbiota

Answer 18

1. nutrient metabolism and salvage
2. xenobiotic and drug metabolism
3. antimicrobial protection to suppress pathogenic organisms
4. immunomodulation
5. dev of gut immune system