Rectum: Supply And Clinical

Question 1

Arterial supply

Answer 1

1. Superior rectal artery
2. Middle rectal arteries
3. Inferior rectal arteries

Question 2

Superior rectal artery

Answer 2

1. Inferior mesenteric artery continuation in front of left common iliac artery
2. Descends in medial limb of pelvic mesocolon root
3. Divides into right and left branches which descend behind rectum and pierce muscular coat to supply mucous membrane of rectum & anal canal upper ½
4. Anastomose with ascending branches of inferior rectal arteries

Question 3

Middle rectal arteries

Answer 3

1. From internal iliac artery anterior division (may be absent)
2. Right and left run medial supplying middle and lower rectum muscle layer
3. They form poor anastomoses with superior and inferior rectal arteries

Question 4

Inferior rectal arteries

Answer 4

1. From internal pudendal artery
2. Supply anal canal lower 1/2 anal sphincters and give ascending branches in submucosa which anastomoses with superior rectal artery

Question 5

Venous drainage

Answer 5

Correspond to arteries
1. Superior rectal vein:
Continues as inferior mesenteric vein ending in splenic vein (portal circulation)
2. Middle rectal vein:
Ends in internal iliac vein (systemic circulation)
3. Inferior rectal vein:
Ends in internal pudendal vein
(systemic circulation)

Question 6

Lymph drainage

Answer 6

1. Upper part: drains into pararectal and inferior mesenteric nodes
   Lymph vessels accompany superior rectal artery
2. Lower part: drains into internal iliac nodes
   Lymph vessels accompany middle rectal artery

Question 7

Nerve supply

Answer 7

1. Sympathetic fibers: from L1,2 via inferior mesenteric plexus
2. Parasympathetic fibers: from pelvic splanchnic nerve (S2,3,4)

Question 8

Per rectal examination male

Answer 8

Right index finger introduced through anal canal to feel:
1. External anal sphincter
2. Penis bulb
3. Prostate
4. 2 seminal vesicles
5. 2 vas deferentia
6. Urinary bladder base

Question 9

Per rectal examination female

Answer 9

Right index finger introduced through anal canal to feel:
1. External anal sphincter
2. Cervix
3. Vagina back

Question 10

Sigmoidscope

Answer 10

Anteroposterior flexures of rectum as it follows sacrum, coccyx curvature, and the 3 lateral flexures must be remembered when one is passing sigmoidoscope to avoid causing patient unnecessary discomfort

Question 11

Proctoscope

Answer 11

Internally illuminated tubular instrument introduced through anus enables physician to examine rectal mucosa greater part under vision