Anterior Triangle Of The Neck Flashcards
Anterior boundary of the anterior triangle of the neck
Midline of neck
Posterior border of the anterior triangle of the neck
Anterior border of sternocleidomastoid
Superior border of the anterior triangle of the neck
Inferior border of the body of mandible
What are the muscle groups of the anterior triangle of the neck?
- infrahyoid muscles
- suprahyoid muscles
- anterior vertebral muscles
Infrahyoid muscles
Thin, strap-like muscles
- sternohyoid
- sternothyroid
- thyrohyoid
- omohyoid
Where is the sternohyoid located?
Supercially, medial to superior belly of omohyoid
Origin of sternohyoid
Posterior surfaces of manubirum of sternum and eternal end of clavicle
Insertion of sternohyoid
Body of hyoid
Nerve supply of sternohyoid
Ansa cervicalis (C1-C3)
Action of sternohyoid
Depresses hyoid bone
Where is sternothyroid located?
Deep to sternohyoid
Origin of sternothyroid
Posterior surface of manubrium of sternum
Insertion of sternothyroid
Oblique line of thyroid cartilage
Nerve supply of sternothyroid
Ansa cervicalis (C1-C3)
Action of sternothyroid
Depresses larynx
Thyrohyoid
Upward continuation of sternothyroid
Origin of thyrohyoid
Oblique line of thyroid cartilage
Insertion of thyrohyoid
Runs superiorly over thyrohyoid membrane, inserts into greater horn and body of hyoid
Nerve supply for thyrohyoid
C1 fibers via hypoglossal nerve
Action of thyrohyoid
Depresses hyoid bone or elevates larynx
Ansa Cervicalis
-nerve loop that contains fibers from ventral rami of C1 to C3 spinal nerves
Lower root of ansa cervicalis
Direct branch of cervical plexus
- contains fibers from ventral rami of C2 and C3
- passes superficial (or deep) to internal vein
- joins upper root to form ansa
Upper root of ansa cervicalis
- appears to originate from hypoglossal nerve, but contains no hypoglossal fibers
- consists of C1 fibers that join CN XII and travel with it for a distance
- separate from CN XII and form upper root of ansa cervicalis
- joins lower root to form ansa
What does ansa cervicalis give branches to?
Sternohyoid
Sternothyroid
Both bellies of omohyoid