Thoracodorsal nerve

Anatomy

Origin

The thoracodorsal nerve arises from the posterior cord of the brachial plexus. It is derived from their ventral rami (in spite of the fact that the latissimus dorsi is found in the back) of cervical nerves C6-C8. It is derived from fibres of the posterior divisions of all three trunks of the brachial plexus.

Course

It passes inferior-ward anterior to the subscapularis muscle and subscapular vessels. It penetrates into the substance of the latissimus dorsi muscle near the lateral border of scapula.

It follows the course of the subscapular artery, along the posterior wall of the axilla to the latissimus dorsi muscle, in which it may be traced as far as the lower border of the muscle.

Distribution

The thoracodorsal nerve innervates the latissimus dorsi muscle on its deep surface.

Clinical significance

The latissimus dorsi is occasionally used for transplantation, and for augmentation of systole in cardiac failure. In these cases, the nerve supply is preserved, and transplanted with the muscle (for example, with facial reanimation).

Posterior cord lesions can result in the loss of adduction of the shoulder joint, as innervation to latissimus dorsi is lost.

Additional images

References

1. Nicole Bentley, J.. (2015-01-01). "Chapter 42 - Anatomy of the Posterior Cord and Its Branches". Academic Press.
2. Katirji, Bashar. (2007-01-01). "Case 11". Mosby.
3. Preston, David C.. (2013-01-01). "30 - Brachial Plexopathy". W.B. Saunders.
4. Bertorini, Tulio E.. (2008-01-01). "1 - Neuromuscular Anatomy and Function". Butterworth-Heinemann.
5. "thoracodorsal nerve - Dictionnaire médical de l'Académie de Médecine".
6. Rea, Paul. (2015-01-01). "Chapter 2 - Upper Limb Nerve Supply". Academic Press.