Ansa cervicalis

The ansa cervicalis is a loop of nerves in the neck that supplies most of the infrahyoid (strap) muscles.

Formation-

It is formed by two roots:

1. Superior root (descendens hypoglossi)

• Fibers from C1 spinal nerve

• Travel briefly with the hypoglossal nerve (CN XII)

2. Inferior root (descendens cervicalis)

• Fibers from C2 and C3 spinal nerves

These two roots join to form a loop called the ansa cervicalis.

Location-

• Lies in the carotid triangle

• Embedded in the carotid sheath (anterior/lateral to it)

Innervation-

• It supplies all infrahyoid muscles except one:

Function-

• Depresses the hyoid bone and larynx

• Important in swallowing and speech