Small Intestine

Question 1

the foregut receives arterial supply from the ____

Answer 1

celiac trunk

Question 2

the midgut receives arterial supply from the ____

Answer 2

superior mesenteric a

Question 3

the hindgut receives arterial supply from the ____

Answer 3

inferior mesenteric a

Question 4

the superior mesenteric artery arises from the abdominal aorta at the level of ____

Answer 4

L1

Question 5

name the organs supplied by the superior mesenteric artery

Answer 5

(midgut)
- jejunum
- ileum
- cecum
- appendix
- ascending colon
- transverse colon

Question 6

name the branches of the superior mesenteric artery

Answer 6

• inf pancreaticoduodenal a
• middle colic a
• right colic a
• ileocolic a
• appendicular a
• jejunal aa
• ileal aa

Question 7

the middle colic artery goes to the ____

Answer 7

transverse colon

Question 8

the right colic artery goes to the ____

Answer 8

ascending colon

Question 9

the ileocolic artery goes to the ____

Answer 9

cecum

Question 10

veins mirror arteries and drain into…

Answer 10

superior or inferior mesenteric vein

Question 11

how many branches do the superior mesenteric vessels have for the jejunum and ileum?

Answer 11

15-18

Question 12

jejunal and ileal arteries join to form loops called ____ that give rise to ____

Answer 12

arterial arcades
vasa recta

Question 13

what vessels form the portal vein?

Answer 13

superior mesenteric v + splenic v

Question 14

Superior mesenteric blood vessels are surrounded by ____

Answer 14

superior mesenteric plexus

Question 15

superior mesenteric plexus

Answer 15

• SNS from T8-T10 (greater & lesser splanchnic nn)
• PSNS from vagus n

Question 16

the small intestine is ____ m long, and is composed of more ____ than ____

Answer 16

6-7m
ileum > jejunum

Question 17

what mesentery covers the small intestine?

Answer 17

principle mesentery

Question 18

what attaches the small intestine to the posterior abdominal wall?

Answer 18

root of mesentery

Question 19

where does the root of the mesentery attach on the small intestine?

Answer 19

duodenojejunal junction (left side L2)
to ileocolic junction (right side SI jt)

Question 20

describe the differences in the pattern of arterial arcades in the jejunum and ileum

Answer 20

• jejunum: simple, not complex
• ileum: shorter, more complex/overlapping

Question 21

describe the differences in the vasa recta of the jejunum and ileum

Answer 21

• jejunum: long, straight
• ileum: shorter, more numerous

Question 22

describe the differences in plicae circulares (mucosal folds) of the jejunum and ileum

Answer 22

• jejunum: taller, more numerous
• ileum: shorter, less numerous (less absorption here)

Question 23

describe the differences in encroaching fat of the jejunum and ileum

Answer 23

• jejunum: not present
• ileum: present

Question 24

what are lacteals?

Answer 24

specialized lymphatic vessels in intestinal villi of the jejunum & ileum that absorb fat

Question 25

lacteals drain sequentially through…

Answer 25

juxta-intestinal, mesenteric, and superior central lymph nodes in principle mesentery

Question 26

mesenteric lymph nodes drain to ____

Answer 26

superior mesenteric nodes

Question 27

terminal ileal branches drain into ____ nodes along the ____

Answer 27

ileocolic
ileocolic a

Question 28

What are Peyer patches?

Answer 28

specialized ileum lymphoid tissue nodules

Question 29

sympathetic innervation of small intestines, ascending and transverse colon

Answer 29

• T8-T10 (v rami) via superior mesenteric plexus
• greater (T5-9), lesser (T10-11), and least splanchnic (T12) nn

Question 30

sympathetic nerves to the small intestines synapse on…

Answer 30

cell bodies of postsynaptic sympathetic neurons of celiac & superior mesenteric ganglia

Question 31

parasympathetic innervation of small intestines, ascending and transverse colon

Answer 31

posterior vagal trunks

Question 32

parasympathetic nerves to the small intestines synapse with…

Answer 32

postsynaptic neurons in intestinal wall