Anatomy

Question 1

Retroperitoneal structures

Answer 1

Retroperitoneal structures include GI structures
that *lack a mesentery

SAD PUCKER:
Suprarenal (adrenal) glands 
Aorta and IVC
Duodenum (2nd through 4th parts)
Pancreas (except tail)
Ureters 
Colon (descending and ascending)
Kidneys
Esophagus (thoracic portion) 
Rectum (partially)

Question 2

Layers of gut wall

Answer 2

inside to outside—MSMS
-Mucosa—epithelium, *lamina propria, *muscularis mucosa
ƒ-Submucosa—includes Submucosal nerve plexus (Meissner), *Secretes fluid
ƒ-Muscularis externa—includes Myenteric nerve plexus (Auerbach), Motility
ƒ-Serosa (when intraperitoneal), adventitia (when retroperitoneal)

Question 3

Above pectinate line

Answer 3

internal hemorrhoids,
*adenocarcinoma

-Internal hemorrhoids receive *visceral innervation and are therefore *not painful

Arterial supply from *superior rectal artery (branch of IMA)

Venous drainage: superior rectal vein–>inferior
mesenteric vein–>portal system.

Lymphatic drainage to *internal iliac lymph nodes.

Question 4

Below pectinate line

Answer 4

external hemorrhoids,
anal fissures, *squamous cell carcinoma

External hemorrhoids receive somatic innervation (*inferior rectal branch of pudendal
nerve) and are therefore *painful if thrombosed

Arterial supply from *inferior rectal artery (branch of internal pudendal artery)

Venous drainage: inferior rectal vein–>internal
pudendal vein–>internal iliac vein–>common iliac vein–>IVC

Lymphatic drainage to *superficial inguinal nodes