Abdominal Wall
- Describe the muscles of anterior abdominal wall and their actions
The anterior abdominal wall is composed of external oblique, internal oblique, and transversus abdominis muscles.
-
External oblique muscle:
- Origin: Ribs 5-12 and iliac crest
- Insertion: Iliac crest, pubic bone, and linea alba
- Action: Flexion, lateral rotation, and compression of abdomen
-
Internal oblique muscle:
- Origin: Iliac crest and pubic bone
- Insertion: Ribs 10-12, xiphoid process, and linea alba
- Action: Extension, lateral rotation, and compression of abdomen
-
Transversus abdominis muscle:
- Origin: Ribs 7-12 and xiphoid process
- Insertion: Linea alba and pubic bone
- Action: Compresses abdomen
- Describe the boundaries and contents of inguinal canal
Boundaries:
- Anterior wall: External oblique aponeurosis
- Posterior wall: Transversalis fascia and psoas major muscle
- Floor: Transversalis fascia and inguinal ligament
- Roof: Internal oblique and transversus abdominis muscles
Contents:
- Ilioinguinal nerve
- Ilioinguinal and illiopubic nerves
- Superficial and deep inguinal lymph nodes
- Precordinal fat
- Spermatic cord (in males)
- Round ligament of uterus (in females)
- Explain the applied anatomy of inguinal canal
Inguinal canal is a passage in the anterior abdominal wall that allows for the transmission of spermatic cord in males and round ligament of uterus in females. It is also a point of potential weakness in the abdominal wall, making it prone to herniation.
Developmental pathway:
- In males: Testicular descent → Processus vaginalis → Inguinal canal
- In females: Testes do not descend, but the processus vaginalis remains patent, allowing for the passage of the round ligament of uterus.
Applied anatomy:
- The inguinal canal is a common site for inguinal hernias, which occur when the abdominal contents protrude through the weakened canal.
- Knowledge of the inguinal canal's boundaries and contents is essential for hernia repair and surgical procedures in the region.