Lecture 22 - Anterior Abdominal Wall

Question 1

What planes divide the abdomen into its 9 regions?

L22 S7

Answer 1

Vertical planes:
-left and right lateral planes (bisect the clavicle)

Horizontal planes:

• transpyloric plane (midway between jugular notch and pubic symphysis)
• intertubercular plane (through turbulence of iliac crest at level of L5)

Question 2

What are the 9 abdominal regions?

L22 S8

Answer 2

Left and right hypochondriac

Epigastric

Left and right lateral (lumbar)

Umbilical

Left and right inguinal

Hypogastric

Question 3

What vertebral levels create the abdominal dermatomes?
What landmarks are associated with what dermatomes?

L22 S12

Answer 3

T7-L1

T7 is at the level of the xiphoid process

T10 is at the level of the umbilicus

L1 is just above the pubic symphysis

Question 4

What are the fascial layers of the abdominal wall?

L22 S15

Answer 4

Subcutaneous fascia:

• superficial (Camper’s fascia) (fatty layer)
• deep superficial (Scarpa’a layer) (membranous layer)

Deep fascia:
-covers anterior abdominal muscles

Transversalis fascia:
-deep to transverse abdominus

Peritoneum:
-serous membrane

Question 5

What is the arterial supply of the abdomen above the umbilicus?

L22 S16

Answer 5

• posterior intercostal artieres (10-11)
• subcostal artery
• lumbar arteries (1-4)
• branches of internal throacic

Question 6

What is the arterial supply of the abdomen below the umbilicus?

L22 S16

Answer 6

External iliac arteries:

• deep epigastric arteries
• deep circumflex arteries

Femoral arteries:

• superficial epigastric arteries
• superficial circumflex iliac arteries
• superficial external pudendal artieries

Question 7

What is the venous drainage of the abdomen?

L22 S18

Answer 7

Deep:
-paired with arteries

Superficial:
-above the umbilicus
—drain to internal thoracic
-below the umbilicus
—drain to femoral veins or external iliac veins

Question 8

What is the lymphatic drainage of the abdomen?

L22 S18

Answer 8

Above the umbilicus:
-drain into axillary and sternal nodes

Below the umbilicus:
-drain into the superficial inguinal nodes

Question 9

What is the proximal attachment of the external oblique?

L22 S26

Answer 9

-external surfaces of ribs 5-12

Question 10

What is the distal attachment of the external oblique?

L22 S26

Answer 10

• linea alba
• pubic tubercle
• anterior iliac crest

Question 11

What is the innervation of the external oblique?

L22 S26

Answer 11

-T7-11, subcostal nerve

Question 12

What is the action of the external oblique?

Answer 12

• compresses and supports abdominal viscera

- flexes and rotates the trunk

Question 13

What is the proximal attachment of the internal oblique?

L22 S26

Answer 13

• thoracolumbar fascia
• anterior 2/3s of iliac crest
• lateral half of iliac ligament

Question 14

What is the distal attachment of the internal oblique?

L22 S26

Answer 14

• linea alba
• pubic crest
• pubis

Question 15

What is the innervation of the internal oblique?

L22 S26

Answer 15

• T7-11
• subcostal nerve
• L1

Question 16

What is the action of the internal oblique?

Answer 16

• compresses and supports abdominal viscera

- flexes and rotates the trunk