Pectinate line

Question 1

Embryologically

Answer 1

Where endoderm meets ectoderm

Question 2

Above pectinate line:

Pathology

Answer 2

1) internal hemorrhoids
2) adenocarcinoma

Above means Adeno

Question 3

Above pectinate line:

Arterial supply

Answer 3

Superior rectal artery (branch of IMA)

Question 4

Above pectinate line:

Venous drainage

Answer 4

Superior rectal vein =>
Inferior mesenteric vein =>
Portal system

Question 5

Above pectinate line:

Pain and lymph drainage

Answer 5

Internal hemorrhoids receive visceral innervation and are therefore not painful.

Lymphatic drainage to deep nodes

Question 6

Below pectinate line:

Pathology

Answer 6

1) external hemorrhoids

2) squamous cell carcinoma (vs. adeno above)

Question 7

Below pectinate line:

Arterial supply

Answer 7

Inferior rectal artery (branch of internal pudendal artery)

Question 8

Below pectinate line:

Venous drainage

Answer 8

Inferior rectal vein =>
Internal pudendal vein =>
Internal iliac vein =>
IVC

Question 9

Below pectinate line:

Pain and lymph drainage

Answer 9

External hemorrhoids from somatic innervation so painful

Lymph drainage to superficial inguinal nodes.