Anterior abdominal wall and inguinal region

Regional classification

• Abdominal cavity can be divided into the abdominal proper and pelvic cavity by a plane which lies at the superior aperture or brim of the bony pelvis.
• 

Superficial anatomy of anterior abdominal wall

• Umbilicus
• Linea transversae: mark position of underlying tendinous intersections of reclusive abdominis muscle.
• Linea semilunares (outer)
• Linea alba (midline)

Layers of anterior abdominal wall

• Camper’s fascia
• Scarpa’s fascia
• Muscles and muscular fascia
• Transversalis fascia
• Extra peritoneal fat
• Peritoneum

Muscles and muscular fascia

Rectus Sheath

• 
• Legenda: Composition:the rectus abdominis muscle is enclosed in a sheath consisting of anterior and posterior laminae. A cresent-shaped arcuate line is formed when an abrupt trasition is made from a posterior lamina consisting of aponeurotic tissue to simple transveralis fascia.

Blood supply and innervation

• Arteries
• Segmentally arranged (lower posterior intercostals, subcostal, lumbar arteries).
• longitudinal channel
• superior epigastric (terminal branch of internal thoracic artery)
• inferior epigastric (branch of the external iliac artery)
• the above two arteries form am important anastamosis which connects the subclavian artery above to the external iliac artery below.
• Nerves
• innervated by intercostal and subcostal nerves (T7-T12), iliohypogastric nerve (L1) and ilioinguinal nerve (L1)
• Dermatomes
• epigastric region (T6, T7, T8)
• Umbilicus (T10)*****
• Above pubis (T12)
• Inguinal Region (L1)

Inguinal Region

• Inguinal ligament
• This is the inferior edge of the external oblique aponerurosis extending from the anterior superior iliac spine to the pubic tubercle.
• Superficial inguinal ring
• medial crus
• lateral crus
• intercrural fibers
• Concept of inguinal canal and deep inguinal ring
• 3 board model
• 

inguinal hernia

• direct vs. indirect inguinal hernia
• in an indirect inguinal hernia, the hernia passes througt deep inguinal ring, lateral to the inferior epigastric vessels
• in a direct inguinal hernia, the hernia passes medial to the inferior epigastric vessles, "directly" throught the posterior wall of the inguinal canal.