Anterior Abdominal Wall

Question 1

What are the landmarks on the ilium related to the abdominal wall?

Answer 1

• Iliac crest

- Anterior superior iliac spine (ASIS)

Question 2

What are the landmarks on the pubis related to the abdominal wall?

Answer 2

• Pubic symphysis at midline (where two pubic bones meet)

- Pubic tubercles (prominences lateral to pubic symphysis)

Question 3

Where does the umbilicus lie?

Answer 3

~L4 vertebral level (midway between xiphoid process and pubic symphysis)

Question 4

Name the layers of the abdominal fascia.

Answer 4

• Camper fascia
• Scarpa fascia: Limits the spread of abdominal wall infections inferiorly into the thigh as it is firmly attached to the iliac crest, inguinal ligament, and pubic symphysis
• Deep (investing) fascia: Surrounds the muscles of the abdominal wall
• Transversalis fascia

Question 5

What are the three main layers of abdominal muscle (superficial to deep)?

Answer 5

• External oblique and aponeurosis
• Internal oblique and aponeurosis
• Transversus abdominis and aponeurosis

Question 6

What causes the “6-pack” lines?

Answer 6

Tendinous intersections

Question 7

What is the difference superiorly and inferiorly to the arcuate line?

Answer 7

• Superior to arcuate line aponeurosis of internal oblique splits to enclose the rectus abdominis
• Inferior to arcuate line: all three aponeurotic layers (external, internal, transversus) pass anterior to the rectus abdominis, leaving only the transversalis fascia deep to the rectus abdominis

Question 8

The scrotum is an extension of the ______

Answer 8

Anterior abdominal wall

Question 9

What is in the deep layer of the scrotum made of?

Answer 9

• Dartos fascia: Contains no fat. Dartos fascia is continuous with the membranous (Scarpa) layer of superficial fascia of the abdominal wall; due to this connection, infections/fluid from the abdominal wall can collect in the scrotum
• Dartos muscle (smooth muscle fibers): contracts in response to cold, giving the skin of the scrotum a wrinkled appearance and helping reduce heat loss by reducing surface area

Question 10

What are the dermatomes of the abdominal wall?

Answer 10

• Superior to umbilicus: T7-T9
• At umbilicus: T10
• Inferior to umbilicus: T11-L1

Question 11

What are the Arteries of the Abdominal Wall?

Answer 11

• Posterior intercostal arteries (10th and 11th)
• Subcostal arteries
• Superior epigastric arteries
• Inferior epigastric arteries: Anastomose with superior epigastric arteries within rectus sheath
• Superficial epigastric arteries

Question 12

What are the Nerves of the Abdominal Wall?

Answer 12

Skin and muscles innervated by ventral rami of
o	T7-T11 (continuation of intercostal nerves)
o	T12 (subcostal nerve)
o	L1 (iliohypogastric and ilioinguinal nerves)

Question 13

What What happens if the IVC is blocked?

Answer 13

-Superior and inferior epigastric vv. (caval-caval anastomosis)
If blood flow through the inferior vena cava is blocked, venous blood within the inferior epigastric veins can be shunted to the superior epigastric veins, and from there to the superior vena cava (via numerous tributaries)

Question 14

What What happens if the liver is blocked?

Answer 14

-Paraumbilical and superficial epigastric vv. (portal-caval anastomosis)
If blood flow through the liver is blocked (portal system blockage), venous blood within the paraumbilical veins (part of the portal system) can be shunted to the superficial epigastric veins. As a result, the veins radiating from the umbilicus dilate; creating a caput medusae

Question 15

Discuss the different Superficial Lymphatic Drainages of the Abdominal Wall

Answer 15

• Superior to the umbilicus: lymph drains to the axillary lymph nodes
• Inferior to the umbilicus: lymph drains to the superficial inguinal lymph nodes

Question 16

What is the gubernaculum?

Answer 16

A ligamentous cord, attaches the inferior pole of the testis to the developing scrotum

Question 17

As the testes descend, what fascial coverings derived from layers of the anterior abdominal wall will get dragged down?

Answer 17

• External spermatic fascia: Derived from external oblique aponeurosis
• Cremaster muscle and fascia: Derived from internal oblique muscle and aponeurosis
• Internal spermatic fascia: Derived from transversalis fascia

Question 18

What does the gubernaculum connect in females?

Answer 18

• Connects the ovary and uterus to the developing labium majus (plural: labia majora)
• Ovarian ligament between ovary and uterus
• Round ligament of the uterus between uterus and labium majus

Question 19

What does the ovarian ligament and round ligament connect, in women?

Answer 19

• Ovarian ligament between ovary and uterus

- Round ligament of the uterus between uterus and labium majus (Its basically like the spermatic cord)

Question 20

Describe the two Inguinal Hernias.

Answer 20

• Indirect (congenital) inguinal hernia: Common. Mass enters the deep inguinal ring, lateral to the inferior epigastric vessels, and traverses the inguinal canal
• Direct (acquired) inguinal hernia: Involves area of weakness (inguinal triangle)