07-04 GIT Gx Large Intestine (Colon) and Anurectum (Colorectal & Anus)

Question 1

blood supply of LARGE INTESTINE is from two sources:

Answer 1

1) the superior mesenteric artery
through the middle, right, and ileocolic branches, and

2) the inferior mesenteric artery
through the left colic, sigmoid, and superior hemorrhoidal branches.

Question 2

The right colon is related posteriorly to

Answer 2

right

ureter, gonadal vessels, duodenum, and kidney


Question 3

also called ‘meandering mesenteric artery’

Answer 3

Arc of Riolan

Question 4

MOST SUSCEPTIBLE TO ISCHEMIA IN CLOSED-LOOP LARGE BOWEL OBSTRUCTION (LBO) because of the direct relationship between wall tension and radius as defined by Laplace’s law:
T ≈ PR
Where T is wall tension, P is pressure, and R is radius

Answer 4

Cecum

Question 5

separates canal from margin

Answer 5

DENTATE LINE

Question 6

lies superior to dentate line

Answer 6

anal canal

Question 7

inferior to dentate line

Answer 7

anal margin

Question 8

“surgical” anal canal extends from anal verge up to the …

Answer 8

anorectal ring

Question 9

innervation above dentate line

Answer 9

autonomic

Question 10

innervation below dentate line

Answer 10

somatic

Question 11

first part of the large intestine

Answer 11

cecum

Question 12

appendix etymology

Answer 12

veriform appencix; Latin vermis, wormilike

Question 13

arterial supply of the cecum

Answer 13

“ileocolic artery”, the terminal branch of SMA

Question 14

arterial supply of the appendix

Answer 14

“appendicular artery”, a branch of the ileocolic artery

Question 15

venous drainage of cecum and appendix

Answer 15

“ileocolic vein”, a tributary of the SMV

Question 16

lymph drainage of the cecum and appendix

Answer 16

passes to lymph nodes in the meso-appendix and to the ileocolic lymph nodes that lie along the ileocolic artery. efferent vessels pass to the SUPERIOR MESENTERY LYMPH NODES

Question 17

nerve supply to the cecum and appendix

Answer 17

sympathetic and parasympathetic nerves from the SUPERIOR MESENTERIC PLEXUS

Question 18

parasympathetic nerve fibers of cecum and appendix

Answer 18

vagus nerves

Question 19

4 parts of the colon

Answer 19

ascending,
transverse,
dedscending
sigmoid

Question 20

second part of the large intestine

Answer 20

ascending colon

Question 21

ascending colon turns left at the …

Answer 21

right colic flexure (hepatic flexure)

Question 22

arterial supply of the ascending colon

Answer 22

(branches of the SMA)

ILEOCOLIC and RIGHT COLIC arteries

Question 23

venous drainage from the ascending colon

Answer 23

(tributaries of the SMV)

ILEOCOLIC and RIGHT COLIC veins

Question 24

lymphatic drainage of the ascending colon

Answer 24

EPICOLIC and PARACOLIC LYMPH NODES -> ILEOCOLIC and intermediate RIGHT COLIC LYMPH NODES -> SUPERIOR MESENTERIC LYMPH NODES

Question 25

nerve supply of ascending colon

Answer 25

SUPERIOR MESENTERIC NERVE PLEXUS

Question 26

3rd, longest, and most mobile part of the large intestine

Answer 26

transverse colon

Question 27

crosses from the right colic flexure to the left colic flexure

Answer 27

transverse colon

Question 28

usually more superior, more acute, and less mobile. right or left colic flexure

Answer 28

left

Question 29

left colic flexure attaches to the diaphragm through the....

Answer 29

phrenicocolic ligament

Question 30

arterial supply of the transverse colon mainly from

Answer 30

MIDDLE COLIC ARTERY, a branch of SMA. However, it may also receive arterial blood from the right and left colic arteries via anastomoses ---- marginal artery (juxtacolic artery)

Question 31

a series of anastomotic arcades that is continued by the left colic and sigmoid arteries to form a continuous arterial channel.

Answer 31

marginal artery (juxtacolic artery)

Question 32

venous drainage of the transverse colon

Answer 32

SMV

Question 33

lymphatic drainage of the transverse colon

Answer 33

middle colic lymph nodes -> superior mesenteric lymph nodes

Question 34

nerve supply of the transverse colon

Answer 34

superior mesenteric nerve plexus

Question 35

S-shaped loop of variable length; links the descending colon to the rectum

Answer 35

sigmoid colon

Question 36

sigmoid colon extends from the iliac fossa to the

Answer 36

third sacral (S3) vertebra

Question 37

termination of the teniae coli, app. 15 cm from the anus, indicates the...

Answer 37

rectosigmoid junction

Question 38

sacculations or pouches of the colon between the teniae

Answer 38

haustra

Question 39

can be identified when 3 taenia coli join proximally

Answer 39

appendix

Question 40

location of ascending and descending colon

Answer 40

retroperitoneal

Question 41

true or false: transverse colon's splenic flexure is directly or indirectly supplied by branches of SMA

Answer 41

false.

Question 42

most common position of appendix

Answer 42

retrocecal

Question 43

most common site of colonic rupture

Answer 43

cecum

Question 44

arterial supply of the descending and sigmoid colon

Answer 44

LEFT COLIC and SIGMOID ARTERIES | branches of inferior mesenteric artery

Question 45

venous drainage of the descending and sigmoid colon

Answer 45

INFERIOR MESENTERIC VEIN -> splenic vein -> hepatic portal vein

Question 46

lymphatic drainage of the descending and sigmoid colon

Answer 46

EPICOLIC and PARACOLIC NODES -> INTERMEDIATE COLIC LYMPH NODES lymph from these nodes passes to the inferior mesenteric lymph nodes. lymph from the left colic flexure may also drain to the superior mesenteric lymph nodes.

Question 47

sympathetic nerve supply of the descending and sigmoid colon

Answer 47

via lumbar (abdominopelvic) splanchnic nerves, the superior mesenteric plexus, and the, peri-arterial plexuses

Question 48

parasympathetic nerve supply of the descending and sigmoid colon

Answer 48

pelvic splanchnic nerves via the inferior hypogastric (pelvic) plexuses

Question 49

the fixed, terminal part of the large intestine

Answer 49

rectum

Question 50

continuous with the sigmoid colon at the

Answer 50

level of S3 vertebra

Question 51

rectum is continuous inferiorly with the

Answer 51

anal canal

Question 52

the RECTOSIGMOID JUNCTION lies anterior to the

Answer 52

S3 vertebra.

Question 53

at level of S3 vertebra, the teniae coli of the sigmoid colon sprea to form a continuous outer longitudinal layer of smooth muscle, and the faty omental appendices are

Answer 53

discontinued

Question 54

rectum etymology

Answer 54

Latin. "rectus", straight.

Question 55

rectum follows the curve of the sacrum and coccyx forming the

Answer 55

sacral flexure of the rectum

Question 56

dilated terminal part of the rectum, lying directly superior to and supported by the pelvic diaphragm (levator ani) and anococcygeal ligament

Answer 56

ampulla of the rectum

Question 57

peritoneum covers the anterior and lateral surfaces of the superior third of the rectum, only the anterior surface of the middle third, and _____ of the inferior third because it is subperitoneal

Answer 57

no surface

Question 58

blood supply of the proximal part of the rectum

Answer 58

"superior rectal artery", | continuation of the abdominal inferior mesenteric artery

Question 59

blood supply of the middle and inferior parts of the rectum

Answer 59

"right and left middle rectal arteries", | anterior division of the internal iliac arteries

Question 60

blood supply of the anorectal junction and anal canal

Answer 60

"inferior rectal arteries", arising from the internal pudental arteries

Question 61

venous drainage of the rectum

Answer 61

superior, middle, and inferior rectal veins. superior rectal veins drains into the portal venous system middle and inferior rectal veins drain into the systemic system. anastomoses occur between the portal and systemic veins in the wall of the anal canal.

Question 62

sympathetic nerve supply of the rectum

Answer 62

via lumbar splanchnic nerves and the | hypogastric/pelvic plexuses

Question 63

parasympathetic nerve supply of the rectum

Answer 63

via the pelvic splanchnic nerves and the | left and right inferior hypogastric plexuses to the rectal (pelvic) plexuses

Question 64

The lymphatic drainage of the anorectal region below the dentate line is through the

Answer 64

inguinal lymph nodes

Question 65

involuntary control [internal or external sphincter?]

Answer 65

internal anal sphincter

Question 66

voluntary control [internal or external sphincter?]

Answer 66

external anal sphincter

Question 67

sooth muscle [internal or external sphincter?]

Answer 67

internal anal sphincter

Question 68

skeletal muscle [internal or external sphincter?]

Answer 68

external anal sphincter

Question 69

includes the puborectalis [internal or external sphincter?]

Answer 69

external anal sphincter