Pelvis And Perineum

Question 1

Give a brief intro of the rectum

Answer 1

The rectum is the distal part of the hind gut. It has a length of 12cm.
It has no tenía colo, appendices epiploicae and has no mesentery.
It extends from the sigmoid colon above at the level of the 3rd sacral vertebrae and runs downward and backward as the anal canal 2- 3cm in front of the tip of coccyx

Question 2

What are the features of the rectum

Answer 2

1. Flexures
   - upper flexure which is convex to the ryt
   - lower flexure which is also convex to the ryt and
   - middle flexure which is convex to the Left.
2. Rectal folds: the rectal folds are sickle shaped transversed folds that correspond with the lateral curve seen externally.
3. Mesorectum: these are connective tissues and fat covering the rectum. They contain superior rectal artery and its branches, superior rectal vein and its tributaries and lymphatic vessels and nodes. It is covered by mesorectal fascia

Question 3

What are the relations of the rectum.

Answer 3

1. Peritoneal relations:
   - upper 3rd: it is covered by peritoneum at its front and sides
   - middle 3rd: it is covered by peritoneum at its front only
   - inferior 3rd: it isn’t covered by the peritoneum
2. Visceral relation:
   A. Anterior:
   I. Inferior 3rd
   - urinary bladder
   - vagina
   - prostate
   - seminal vesicles
   - ductus deferens
   - terminal part of the ureter
   II. Upper 3rd:
   - rectovesical or rectouterine pouch containing small intestine
   - sigmoid colon in men
3. Posterior relation:
   - sympathetic trunk
   - bones: lower 3 pieces of sacrum, coccyx and anococcygeal ligament
   - muscles: piriformis, coccygeus, levator Ani muscles
   - median sacral, superior rectal and lower lateral sacral vessels

Question 4

Arterial supply of rectum

Answer 4

1. Superior rectal artery
2. Inferior rectal artery
3. Median sacral vessel

Question 5

Venous drainage of the rectum

Answer 5

1. Internal venous plexus: in the submucosa
2. External venous plexus: outside the muscular wall.

Question 6

Lymph drainage of rectum

Answer 6

1. Para- aortic lymph nodes around the superior rectal arteries from inferior mesenteric plexus
2. Internal iliac group of lymph nodes along the middle rectal and inferior rectal arteries along the medial sacral artery

Question 7

Nerve supply of the rectum

Answer 7

1. Sympathetic supply: by fibres that accompany the inferior mesenteric and superior rectal arteries from inferior mesenteric plexus
2. parasympathetic supply: from S2-S4 by pelvic splanchnic nerve via hypogastric plexus

Question 8

Embryology of rectum

Answer 8

The rectum is derived from the anorectal canal and proctodeum at 4th week of IUL

Question 9

Histology of the rectum

Answer 9

1. Mucosa: simple columnar epithelium
2. Submucosa: vessels
3. Muscular layer: inner circular and outer longitudinal
4. Serosa/adventitia: the upper and middle 3rd contains serosa. While the lower 3rd is adventitia

Question 10

Clinicals of rectum

Answer 10

Rectal prolapse and cancer of rectum