Week 11 - Abdominal Wall & Inguinal Region

Question 1

Name the superior, inferior, anterior, and posterior boundaries of the inguinal canal.

Answer 1

Superior: Arching fibres of internal oblique and transversus abdominis

Inferior: Infolded inguinal ligament

Anterior: External oblique aponeurosis (reinforced laterally by internal oblique)

Posterior: Transversalis fascia (and conjoint tendon medially)

Question 2

Consider the contents of the inguinal canal in the male. Which of the following structures passes through the inguinal canal, but does not enter it via the deep inguinal ring?

• a) Ilioinguinal nerve
• b) Genital branch of the genitofemoral nerve
• c) Ductus deferens
• d) Lymphatic vessels
• e) Testicular artery

Answer 2

• a) Ilioinguinal nerve
• b) Genital branch of the genitofemoral nerve
• c) Ductus deferens
• d) Lymphatic vessels
• e) Testicular artery

Question 3

What is the difference between the mid-inguinal point and the mid-point of the inguinal ligament?

What is the significance of each of these points?

Answer 3

• Mid-inguinal point: Halfway between the pubic symphysis and the ASIS
  
  • Significance: The femoral pulse may be palpated here
• Mid-point of the inguinal ligament: Halfway between the pubic tubercle and the ASIS
  
  • Significance: This is the location of the deep inguinal ring

Question 4

You are the general surgeon at a rural hospital, and you are performing an open appendicectomy. This requires you to make an oblique incision in the right iliac fossa at McBurney’s point (known as McBurney’s incision). Which layers of the abdominal wall will your scalpel dissect to open the abdominal cavity? List the layers from superficial to deep.

Answer 4

Layers of anterior abdominal wall

1. Skin
2. Superficial fascia - superficial fatty layer (Camper’s fascia) and a deeper membranous layer (Scarpa’s fascia)
3. Abdominal muscles: three flat muscles and 2 vertical muscles
4. Transversalis fascia
5. Extraperitoneal fat
6. Parietal peritoneum

McBurney’s point - Classically used as a guide to the location of the base of the appendix, determined by pain elicited by the pressure of a single digit at the point (McBurney’s sign).

Question 5

What is the significance of Hesselbach’s triangle and what are its borders?

Answer 5

This is an area of weakness of the abdominal wall through which direct inguinal hernias protrude.

Laterally - inferior epigastric vessels

Medially - lateral border of rectus abdominus

Inferiorly - inguinal ligament

Question 6

Answer 6