Rectus Sheath

Original Editor - lucinda hampton

Top Contributors - Lucinda hampton and Kim Jackson  

Introduction[edit | edit source]

Rectus abdominis sheath.jpeg

The Rectus Sheath is a multilayered aponeurosis, being a durable, resilient, fibrous compartment that contains both the rectus abdominis muscle and the pyramidalis muscle. [1]

It covers the anterior and posterior surfaces of the upper three-quarters of the rectus abdominis muscle, and the lower quarter of its anterior surface. The lower quarter of the posterior surface of the rectus abdominis muscle isn’t covered with rectus sheath at all, but rather lays directly on the transversalis fascia.[2]

Image 1: Dissection of a human Rectus abdominis sheath

Key Facts[edit | edit source]

Definition Multilayered aponeurosis that encloses the rectus abdominis and pyramidalis muscles
Walls of upper three-quarters Anterior wall: Aponeurosis of external abdominal oblique muscle and aponeurosis of internal abdominal oblique muscle

Posterior wall: Aponeurosis of internal abdominal oblique muscle and aponeurosis of transversus abdominis muscle

Walls of lower quarter Anterior wall: As above

Posterior wall: Absent

Function Protection of anterior abdominal muscles and vessels.

Provides maximal compression and support of abdominal organs.

Contents[edit | edit source]

  1. Rectus abdominis and Pyramidalis muscles
  2. Lower 6 thoracic nerves and accompanying branches of the posterior intercostal vessels
  3. Superior and inferior epigastric vessels[3]

Image 3: Figure 2: Rectus sheath (Gray's illustrations)

References[edit | edit source]

  1. Sevensma KE, Leavitt L, Pihl KD. Anatomy, Abdomen and Pelvis, Rectus Sheath.Available: (accessed 19.12.2021)
  2. Ken hub Rectus Sheath Available: (accessed 19.12.2021)
  3. Radiopedia Available: 19.12.2021)