Transversus Abdominis Flashcards

Explore transversus abdominis anatomy, including its attachments, horizontal fibers, innervation, actions, fascial relations, and clinical importance.

Card 1 of 25Question

What is the transversus abdominis muscle?

The deepest of the three flat muscles of the anterolateral abdominal wall.

In This Section

1. What is the transversus abdominis muscle?

The deepest of the three flat muscles of the anterolateral abdominal wall.

2. Which abdominal wall muscle lies immediately superficial to the transversus abdominis?

The internal oblique muscle.

3. From which costal structures does the transversus abdominis originate?

The internal surfaces of the lower six costal cartilages.

4. Which posterior fascial structure provides an origin for the transversus abdominis?

The thoracolumbar fascia.

5. Which part of the iliac crest provides an origin for the transversus abdominis?

The inner lip of the iliac crest.

6. Which portion of the inguinal ligament provides an origin for the transversus abdominis?

The lateral third of the inguinal ligament.

7. Where does the transversus abdominis insert medially?

The linea alba through its broad aponeurosis.

8. Where do the inferior aponeurotic fibers of the transversus abdominis insert?

The pubic crest and pecten pubis, sometimes through a conjoint tendon.

9. What is the predominant fiber direction of the transversus abdominis?

Approximately horizontal, extending transversely around the abdominal wall.

10. Which nerves provide motor innervation to the transversus abdominis?

Thoracoabdominal nerves T7 to T11, the subcostal nerve T12, and the iliohypogastric and ilioinguinal nerves from L1.

11. What is the principal action of the transversus abdominis?

Compression of the abdominal contents.

12. How does the transversus abdominis contribute to trunk stability?

It tensions the abdominal wall and contributes to control of intra-abdominal pressure.

13. How does the transversus abdominis assist forced expiration?

It increases intra-abdominal pressure, helping displace the diaphragm superiorly.

14. Which activities use transversus abdominis contraction to increase intra-abdominal pressure?

Coughing, sneezing, vomiting, defecation, and childbirth.

15. Which fascial layer lies immediately deep to the transversus abdominis?

The transversalis fascia.

16. Between which muscles is the transversus abdominis plane located?

Between the internal oblique and transversus abdominis muscles.

17. What structures travel through the transversus abdominis plane?

Segmental nerves and vessels supplying the anterolateral abdominal wall.

18. What is the anatomical basis of a transversus abdominis plane block?

Local anesthetic is injected into the neurovascular plane to block abdominal wall nerves.

19. How does the transversus abdominis aponeurosis contribute to the rectus sheath above the arcuate line?

It contributes to the posterior layer of the rectus sheath.

20. How does the transversus abdominis aponeurosis pass relative to rectus abdominis below the arcuate line?

It passes anterior to the rectus abdominis.

21. What is the conjoint tendon?

A variable common aponeurotic insertion of the internal oblique and transversus abdominis near the pubis.

22. How do the inferior fibers of the transversus abdominis contribute to the inguinal canal?

They arch over the canal and contribute to its roof.

23. Why does the transversus abdominis not form a distinct covering of the spermatic cord?

Its inferior fibers arch above the deep inguinal ring rather than extending around the cord.

24. How does contraction of the transversus abdominis help protect against inguinal herniation?

Its arching fibers help compress the inguinal canal as part of the shutter mechanism.

25. What is the transversus abdominis release technique?

A posterior abdominal wall reconstruction technique that creates a retromuscular plane for mesh placement.