Rectus Abdominis Flashcards

Study rectus abdominis anatomy, including its attachments, tendinous intersections, nerve supply, actions, and rectus sheath relationships.

Card 1 of 26Question

What is the rectus abdominis muscle?

A paired, vertically oriented strap muscle forming part of the anterior abdominal wall.

In This Section

1. What is the rectus abdominis muscle?

A paired, vertically oriented strap muscle forming part of the anterior abdominal wall.

2. Where is the rectus abdominis located relative to the linea alba?

On either side of the linea alba.

3. What is the origin of the rectus abdominis muscle?

The pubic symphysis and pubic crest.

4. Where does the rectus abdominis muscle insert?

The xiphoid process and costal cartilages of ribs 5 to 7.

5. What is the primary action of bilateral rectus abdominis contraction?

Flexion of the trunk and lumbar vertebral column.

6. How does the rectus abdominis act on the pelvis?

It produces posterior pelvic tilt when the thorax is fixed.

7. How does the rectus abdominis contribute to forced expiration?

It compresses abdominal contents and helps depress the rib cage.

8. Which nerves provide motor innervation to the rectus abdominis?

The thoracoabdominal nerves from T7 to T11 and the subcostal nerve from T12.

9. Which major arteries supply the rectus abdominis?

The superior and inferior epigastric arteries.

10. From which artery does the superior epigastric artery originate?

The internal thoracic artery.

11. From which artery does the inferior epigastric artery originate?

The external iliac artery.

12. Where do the superior and inferior epigastric arteries anastomose?

Within the rectus sheath, deep to the rectus abdominis muscle.

13. What are the tendinous intersections of the rectus abdominis?

Transverse fibrous bands that partially divide the muscle into segments.

14. How many tendinous intersections are commonly present in the rectus abdominis?

Usually three, although the number varies.

15. To which part of the rectus sheath are the tendinous intersections firmly attached?

The anterior layer of the rectus sheath.

16. What forms the rectus sheath surrounding the rectus abdominis?

The aponeuroses of the external oblique, internal oblique, and transversus abdominis muscles.

17. Which aponeuroses form the anterior rectus sheath above the arcuate line?

The external oblique aponeurosis and anterior lamina of the internal oblique aponeurosis.

18. Which aponeuroses form the posterior rectus sheath above the arcuate line?

The posterior lamina of the internal oblique aponeurosis and the transversus abdominis aponeurosis.

19. How does the rectus sheath arrangement change below the arcuate line?

All three flat muscle aponeuroses pass anterior to the rectus abdominis.

20. Which layers lie directly posterior to the rectus abdominis below the arcuate line?

Transversalis fascia, extraperitoneal connective tissue, and parietal peritoneum.

21. What anatomical structure marks the lateral border of the rectus abdominis?

The linea semilunaris.

22. Which small muscle may lie anterior to the inferior rectus abdominis?

The pyramidalis muscle.

23. What is diastasis recti?

Widening of the linea alba with increased separation of the rectus abdominis muscles without a true fascial defect.

24. What is a rectus sheath hematoma?

A collection of blood within the rectus sheath caused by vascular injury or muscle tearing.

25. Why can rectus sheath hematomas extend more extensively below the arcuate line?

The posterior aponeurotic sheath is absent, allowing blood to spread through less confined tissue planes.

26. What is the anatomical basis of the rectus sheath block?

Local anesthetic is placed between the rectus abdominis and posterior rectus sheath to block anterior cutaneous nerve branches.