LARGE INTESTINE

Question 1

what is the general function of the large intestine?

Answer 1

water is absorbed from the chyme forming semi solid faeces

Question 2

what does it consist of

Answer 2

cecum, appendix, ascending, transverse and descending colon, rectum, anal canal

Question 3

four ways to distingiush it from small intestine

Answer 3

epiploic appendages, teniae coli, haustra, diameter

Question 4

where is the cecum located?

Answer 4

iliac fossa of the right lower quadrant - when enlarged it can be palpated through the anterolateral abdominal wall

Question 5

is the cecum mobile?

Answer 5

has no mesentary but usually held into place by a fold of peritoneun

Question 6

how does the ileum enter the cecum?

Answer 6

obliquely and it invaginates in

Question 7

where is the appendix and what does it contain

Answer 7

arises from the posteriomedial aspect of the cecum. contains masses of lymphoid tissue

Question 8

does the appendix have a mesentary?

Answer 8

mesoappendix is derived from the posterior ileal mesentary

Question 9

blood supply to the cecum and appendix

Answer 9

both are midgut derivatves so are from SMA which gives off ileocolic branch from which an appendicular branch arises. they are drained by the ileocolic vein

Question 10

where does the ascending colon run from

Answer 10

cecum to the right lobe of the liver at the hepatic colic flexure

Question 11

is the ascending colon retroperitoneal?

Answer 11

secondarily retroperitoneal - covered with peritoneum on it’s anterior and sides

Question 12

what seperates the ascending colon from the anterior abdominal wall?

Answer 12

the greater omentum

Question 13

describe the position of the right paracolic gutter

Answer 13

deep vertical groove lined with parietal peritoneum between the lateral aspect of the ascending colon and the adjacent abdominal wall

Question 14

where does the transverse colon run from?

Answer 14

the right to the left colic flexures

Question 15

where is the phrenocolic ligament?

Answer 15

where the transverse colon attaches to the diaphragm at the splenic flexure

Question 16

where is the transverse mesocolon?

Answer 16

mesentary of the transverse colon loops down to the level of the iliac crests and is fused to the posterior wall of the omental bursa

Question 17

is the TC mobile?

Answer 17

freely moving - can hang down to the level of the iliac crests in tall, thin people.

Question 18

which parts of the descending colon are covered with peritoneum?

Answer 18

anterior and lateral

Question 19

is the DC retroperitoneal?

Answer 19

• it is bound to the posterior abdominal wall

Question 20

does the descending colon have a mesentary?

Answer 20

has a short mesentary in 33% of people

Question 21

describe the position of the left paracolic gutter

Answer 21

deep vertical groove lined with parital peritoneum between the lateral aspect of the descending colon and the adjacent abdonminal wall

Question 22

where does the sigmoid colon lie?

Answer 22

in the left iliac fossa

Question 23

where do the teniae coli terminate?

Answer 23

15cm from the anus at the rectosigmoid junction

Question 24

does the sigmoid colon have a mesentary?

Answer 24

it has a long mesentary called the sigmoid mesocolon which is considerably mobile and could lead to a volvulous

Question 25

where is the sigmoid colon in relation to the left ureter and division of the left common iliac

Answer 25

they lie retroperitoneally, posterior to the apex of the root of the sigmoid mesocolon.

Question 26

what is the blood supply to the ascending colon and right colic flexure?

Answer 26

ileocolic and right colic from the SMA anastomose with eachother and with the right branch of the middle colic to form a series of arcades running continuously round the large intestine called the marginal artery

Question 27

blood supply to the transverse colon?

Answer 27

mid and hundgut - mainly from the SMA but a small amount from the IMA . right colic from the SMA and left colic from the IMA. may also receive a small amount from the marginal

Question 28

venous drainage of the large intestine up to the transverse colon

Answer 28

middle colic vein which drains into the SMV and then into the HPV -joins with splenic behind the head of the pancreas

Question 29

blood supply to the descending and sigmoid colon

Answer 29

hindgut so both from the IMA
Left colic and sigmoid from the IMA
venous drainage is left colic and sigmoid veins from IMV