1 - Inguinal Region

Question 1

Objectives: Define the borders, muscle, and fascia components of the inguinal canal

Start, Roof, End

Answer 1

• Borders:
• Composition: External Oblique Aponeurosis forms the inguinal ligament
  
  • ​Lacunar Ligament - medial extension
  • Pectineal Ligament - Thickening of periosteum continuous with lacunar ligament at pectineal line
• Start: Deep Inguinal Ring (Internal) - Lateral to Inf. Epigastric Vessels
• Roof: Internal Oblique Muscle / Transversus Abdominus (apon)
• End: Superficial Inguinal Ring (External) - opening in External Oblique Muscle

Question 2

Objectives: Define the borders, muscle, and fascia components of the inguinal canal

Borders

Answer 2

• Anterior Wall:
  
  • Apon. of External Oblique M. (entire canal)
  • Apon. of Internal Oblique M. (lat 1/3)
• Posterior Wall:
  
  • Transversalis Fascia (entire canal)
  • Conjoint Tendon (medial 1/3)
• Roof (Superior Wall):
  
  • Mm Fibers/Apon. of Internal Oblique M.
  • Apon. of Transversus Abdominus M.
• Floor (Inferior Wall):
  
  • Inguinal Ligament (entire canal)
  • Lacunar Ligament (medial 1/3)

Question 3

Objectives: Identify structures transmitted through inguinal canal in males and females

Answer 3

• Male: Spermatic Cord (larger)
• Female: Round Ligament of Uterus
• Both:
  
  • ilioinguinal N. (enters lateral)
  • Genital Br. of Genitofemoral N.

Question 4

Objectives: Understand formation of inguinal canal and testicular descent as it relates to coverings of spermatic cord and testis

Processus Vaginalis

Gubernaculum

Answer 4

• Processus Vaginalis: Initial evagination of periotneum into ventral abdominal wall; occurs ind. of testes descent
  
  • Persists as covering of testis as tunica vaginalis
• Gubernaculum: Band that extends from gonad through inguinal canal to labioscrotal swelling
  
  • ​Males: Connects gonad to scrotum
  • Females: Round Lig. of Uterus
• As testes “push” through inguinal canal, they take layers with them (except tranversus abdominus)

Question 5

Objectives: Know contents of spermatic cord and corresponding layers of abdominal wll and testes/spermatic cord

Answer 5

• Layers:
  
  • External Oblique M. = (1) External Spermatic Fascia
  • Internal Oblique M. = (2) Cremasteric Fascia
  • Transversalis Fascia = (3) Internal Spermatic Fascia
• Components:
  
  • ​Testicular Artery (from aorta)
  • Ductus Deferens and Artery
  • Pampiniform Plexus of Testicular Vein
  • Genital branch of Genitofemoral Nerve (L1, L2)
  • Lymphatics, Autonomics, Cermasteric A.
• Note: Transversus Abdominis does not contribute a layer

Question 6

Objectives: Know types of hernias that occur in inguinal region and understand difference between direct vs. indirect inguinal hernia and femoral hernia

Answer 6

• Indirect Hernia:
  
  • Most Common, Congenital
  • Lateral to Inferior Epigastric
  • Through Deep Ring
• Direct Hernia:
  
  • Acquired
  • Medial to Inferior Epigastric
  • Hesselbach’s Triangle (peritoneum / transversalis fascia)
• Femoral:
  
  • Femoral Ring
  • Below, Lateral to Pubic Tubercle
  • Irreducible Hernia

Question 7

Clinical: Cryptorchidism

Answer 7

Incomplete testes descent such that one or both testes remain in body cavity or inguinal canal

Question 8

Explain the layers of the scrotum and its contents

Answer 8

• Layers:
  
  • Skin
  • Dartos Layer - Continuation of Camper’s Fascia (no fat), contraction reduces surface area
• Contents:
  
  • Testis - Sperm and androgen production
    
    • Layers:
      
      • Tunica Albuginea - White fibrous capsule
      • Tunica Vaginalis - Derived from parietal peritoneum (Processus Vaginalis)
        
        • Shiny Visceral layer
        • Parietal layer