This document describes the anatomy of the anterior abdominal wall. It lists and describes the layers of muscles that make up the abdominal wall (external oblique, internal oblique, transversus abdominis), as well as the rectus sheath, inguinal canal, superficial and deep inguinal rings. It provides details on the nerve supply, direction of fibers, and actions of the muscles. It also describes the formation and contents of the anterior and posterior walls of the rectus sheath.

1. Identification Mention
Rectus Abdominis Muscle (RA)
Directions of fibers, Nerve supply, Actions
External Oblique Muscle (EO)
Internal Oblique Muscle (IO)
Transversus Abdominis Muscle (TA)
Anterior Wall of Rectus Sheath
Formation of the wall at different levels, Contents
Posterior Wall of Rectus Sheath
Arcuate Line -
Superficial Inguinal Ring In which layer (origin), Contents passing through
Deep Inguinal Ring In which layer (origin)
Inguinal Canal Nature, Length, Direction, Structures passing through, Boundaries
Linea Alba Muscles formed it
ANTERIOR ABDOMINAL WALL
Prepared By AbdulRahman AlTokhy Reviewed By Dr. Muhammad Ramadan

2. External Oblique Muscle
Internal Oblique Muscle
Transversus Abdominis Muscle
Posterior Wall of Rectus Sheath
Arcuate Line
Anterior Wall of Rectus Sheath
Linea Alba
Rectus Abdominis Muscle
Anterior Posterior

3. External Oblique Muscle
Internal Oblique Muscle
Transversus Abdominis Muscle
Posterior Wall of Rectus Sheath
Arcuate Line
Anterior Wall of Rectus Sheath
Linea Alba
Rectus Abdominis Muscle
Anterior Posterior

4. Anterior Posterior
External Oblique Muscle
Internal Oblique Muscle
Transversus Abdominis Muscle
Posterior Wall of Rectus Sheath
Arcuate Line
Anterior Wall of Rectus Sheath
Linea Alba
Rectus Abdominis Muscle

5. Posterior Posterior
Deep Inguinal Ring
Inguinal Canal
Superficial Inguinal Ring

6. Muscle Directions of fibers Nerve supply Actions
Rectus Abdominis Muscle Vertical
- T7 – T12
- Subcostal
- Ilioinguinal
1- Keeping abdominal viscera in position.
2- Muscles of expiration.
3- Straining.
4- Rectus Abdominis Muscle, help in lateral flexion.
5- Oblique and Transversus Muscles help in lateral
rotation.
External Oblique Muscle Down, forward & medially
Internal Oblique Muscle Upward, forward & medially
Transversus Abdominis Muscle Transverse
External Oblique Muscle
Internal Oblique Muscle Forming Linea Alba
Transversus Abdominis Muscle

7. Contents of the rectus sheath:
2 Muscles 2 Vessels 2 Nerves
1-Rectus abdominis muscle 3-Superior epigastric vessels 5-Terminal parts of T7 - T11 nerves
2-Pyramidalis muscle 4-Inferior epigastric vessels 6-Terminal part of T12 nerve
Formation of Anterior wall of the rectus sheath:
Above Costal margin: by the aponeurosis of EO.
Between Costal margin and Arcuate line: by the aponeurosis of EO. & the anterior lamella of aponeurosis of IO.
Below Arcuate line: by the aponeurosis of EO, IO & TA.
Formation of Posterior wall of the rectus sheath:
Above Costal margin: by the 5th, 6th & 7th costal cartilages.
Between Costal margin and Arcuate line: by the posterior lamella of the aponeurosis of IO and TA.
Below Arcuate line: by the fascia transversalis.

8. The Inguinal Canal
Nature
An oblique space in the lower part of anterior abdominal wall extending from the deep inguinal
ring to the superficial inguinal ring.
Length 4 cm long.
Direction Downwards forwards and medially.
Structures passing through Ilioinguinal nerve Spermatic cord in males Round ligament of the uterus in females
Boundaries
Anterior wall Posterior wall Roof Floor
External abdominal
oblique aponeurosis
Fascia transversalis Arched fibers of the
internal oblique and
transversus abdominis
Concave upper surface
of the inguinal ligament.Internal abdominal
oblique
Conjoint tendon
Superficial Inguinal Ring
Origin: Aponeurosis of External oblique.
Contents passing through Inguinal Canal
Ilioinguinal nerve Spermatic cord in males Round ligament of uterus in females
Deep Inguinal Ring
Origin: Fascia Transversalis.