intro to lower GI tract W4

Question 1

what is defined as the lower GI tract

Answer 1

GI tract beyond the pylorus

Question 2

3 sections of the small intestine?

Answer 2

duodenum
jejunum
ileum

Question 3

where does the ileum join the large intestine (colon)?

Answer 3

right iliac fossa
ileo-caecal valve

Question 4

4 sections of the duodenum?

Answer 4

straight, descending, horizontal, ascending

Question 5

what section of the duodenum does the pancreas exit from?

Answer 5

descending (second part)

Question 6

where does the duodenum and jejunum meet

Answer 6

duodenojejunal flexure (beyond sharp turn)

Question 7

jejunum and ileum transition?

Answer 7

seamless transition

Question 8

purpose of small intestine

Answer 8

absorb nutrients and water from diet

Question 9

small intestine mucosa features

Answer 9

folded into millions of villi
increased surface area for absorption
‘carpet-like’ appearance

Question 10

what does each villus in the small intestine contain

Answer 10

blood vessels and a lymph vessel

Question 11

name of surface cells in small intestine? features?

Answer 11

enterocytes
microvilli form brush border

Question 12

small intestine cells?

Answer 12

enterocytes (surface)
goblet cells (secrete mucus)
enteroendocrine cells (secrete hormones)
stem cells (crypts adjacent to villi)

Question 13

sections of the large intestine?

Answer 13

caecum
colon (ascending, transverse, descending, sigmoid)
rectum
anal canal

Question 14

features of the rectum

Answer 14

repository for stool
ends at anal canal (transition to squamous mucosa)
anal sphincter - internal (smooth) and external (striated)

Question 15

features of the colon wall

Answer 15

mucus secreting glands
no villi but crypts

Question 16

features of the colon wall muscles

Answer 16

grouped into dense strips (taeniae coli) and rings. these are shorter than the bowel and mean pouches (haustra) are formed.

Question 17

appendix features

Answer 17

variable position
may have a role in gut microflora

Question 18

what is the peritoneum?

Answer 18

continuous membrane covering most abdominal organs
two layers - visceral and parietal

Question 19

visceral layer of peritoneum?

Answer 19

lines organs, is their serosa

Question 20

parietal layer of peritoneum?

Answer 20

lines walls of abdominal cavity

Question 21

retroperitoneal meaning? which organs are found here?

Answer 21

extraperitoneal and behind the peritoneum
pancreas, kidneys, adrenals, urinary tract, parts of duodenum, colon and rectum

Question 22

mesentery features?

Answer 22

large fold of parietal peritoneum that is attached to the small intestine and prevents it knotting up (also blood supply)

Question 23

omentum features?

Answer 23

continuation of the serosa of the stomach. apron which hangs over the intestines. if perforation/inflammation, it can wrap around the segment and seal it off.