Anterior Abdominal Wall

Question 1

What are the two factors that are required for development of a hernia

Answer 1

1) Structural weakness (can be normal anatomical weakness or abnormal weakness, eg, congenital diaphragmatic hernia or surgical scars)
2) Increased pressure (Repeated bouts of increased intra-abdominal pressure)

Question 2

What are are the lines of rectus abdominis

Answer 2

Linea alba - Midline (from xiphoid process to pubic symphysis)

Linea semilunaris - Lateral boarder of rectus abdominis

Question 3

What are the muscles are in the anterior abdominal

Answer 3

Rectus Abdominis, External oblique, internal oblique, Transversus Abdominis

Question 4

Describe the layers of the lateral abdominal wall

Answer 4

• Skin,
• Subcutaneous tissue (Fatty layer = Camper’s fascia and a membranous layer = Scarpa’s),
• Abdominal muscles with investing fasciae,
• Transversalis fascia,
• Extraperitoneal fat,
• Parietal Peritoneum.

Question 5

Describe how the fascia of the abdominal wall continues with the perineum

Answer 5

• Camper’s fascia is continuous with the subcutaneous tissue of the perineum.
• Scarpa’s fascia is continuous with colles’ fascia

Question 6

Name the functions of abdominal wall muscles

Answer 6

They support abdominal contents, raise intra-abdominal pressure, withstand pressure from descent of the diaphragm, respiration, support vertebral column, flex, laterally flex and rotate the trunk.

Question 7

Describe the direction of the anterolateral abdominal wall muscle fibres

Answer 7

• External Oblique - Anteroinferior direction (hands in pocket).
• Internal oblique - Anterosuperior direction (hands on chest)
• Transversus abdominis - Horizontal

Question 8

Describe what forms the anterior and posterior rectus sheath above the arcuate line

Answer 8

Anteriorly - External oblique aponeurosis and internal oblique aponeurosis.

Posteriorly - Transversus abdominis aponeurosis, internal oblique aponeurosis, transversalis fascia, parietal peritoneum

Question 9

Describe what forms the anterior and posterior rectus sheath below the arcuate line

Answer 9

Anteriorly - External oblique aponeurosis, internal oblique aponeurosis and transversus abdominis.

Posteriorly - Transversalis fascia and parietal peritoneum

Question 10

Describe the nerve supply to the anterolateral abdominal wall

Answer 10

• 7th to 11th IC nerves become thoracoabdominal nerves,
• Subcostal (T12),
• Iliohypogastric (L1),
• Ilioinguinal (L1),

Question 11

Describe the blood supply to the anterior abdominal wall

Answer 11

Superior epigastric arteries which are a continuation of the internal thoracic

Inferior epigastric arteries - branch of external iliac artery.

Question 12

Describe the blood supply to the lateral abdominal wall

Answer 12

Intercostal and subcostal arteries which are continuation of posterior intercostal arteries

Question 13

Describe the contents of inguinal canal?

Answer 13

• Spermatic cord (males),
• Round ligament of the uterus (female)
• Blood and lymphatic vessels,
• Ilioinguinal nerve

Question 14

Describe the formation of the inguinal canal

Answer 14

Testis develop on the posterior abdominal wall then descend during foetal development and puberty. During descent of the testis it pulls layers of the abdominal wall along with it which contribute to the layers of the spermatic cord

Question 15

What is the anterior wall of the inguinal canal

Answer 15

External oblique aponeurosis (total), internal oblique muscle (laterally)

Question 16

What is the posterior wall of the inguinal canal made up of?

Answer 16

Transversalis fascia (laterally) and Conjoint tendon (medially)

Question 17

What is the roof of the inguinal canal made out of?

Answer 17

Transversalis fascia (laterally), Arches of internal oblique and transversus abdominis aponeurosis (centrally), External oblique aponeurosis (medially)

Question 18

What is the floor of the inguinal canal

Answer 18

Gutter of infolded inguinal ligament

Question 19

Name the boarders of the Hesselbach’s Tringle

Answer 19

Medially - Lateral boarder of retus abdominis.

Inferolateral - Inguinal ligament.

Superolateral boarder - Inferior epigastric artery

Question 20

What is the clinical significance of Hesselbach’s Triangle

Answer 20

Site of direct inguinal herniation

Question 21

Describe what is a direct inguinal hernia

Answer 21

When is directly through abdominal wall structures. It is MEDIAL to inferior epigastric artery. It passes through Hesselbach’s triangle to superficial ring. It is parallel to spermatic cord

Question 22

Describe what an Indirect Inguinal hernia is?

Answer 22

It uses inguinal canal and deep inguinal ring. It passes LATERAL to the inferior epigastric artery. It is within spermatic cord or layers of abdominal wall

Question 23

What is the myopectineal orifice

Answer 23

It is an area of innate weakness.

Question 24

Where is the deep inguinal ring and the superfical inguinal ring

Answer 24

Deep - Superior to the half wat point along the inguinal ligament

Superficial - Just superior and lateral to the pubic tubercle