Anatomy of the neck Flashcards
Define the posterior triangle of the neck
Bounded by the posterior border of the sternocleidomastoid muscle, anterior border of the trapezius muscle and the middle third of the clavicle.
Define the anterior triangle of the neck
Bounded by the anterior border of the sternocleidomastoid muscle, the inferior border of the mandible and the midline of the neck.
What are the names of the triangles that the anterior triangle can be subdivided into?
- submandibular
- carotid
- muscular
- submental
What is the origin of the sternocleidomastoid muscle?
The sternal head originates from the manubrium
The clavicular head originates from the medial third of the clavicle
Where does the sternocleidomastoid muscle insert?
Into the mastoid process and lateral half of the superior nuchal line
Describe the innervation of the sternocleidomastoid muscle
The spinal root of cranial nerve XI and C2-3
Describe the main actions of the sternocleidomastoid muscle
Tilts head to one side i.e. laterally flexes and rotates the head so the face is turned superiorly toward the opposite side; acting together the muscles flex the neck
What is the origin of the posterior scalene muscle?
The posterior tubercles of the transverse processes of C4-C6
Where does the posterior scalene muscle insert?
2nd rib
What is the innervation of the posterior scalene muscle
C6-C8
What is the main action of the posterior scalene muscle
Flexes head laterally; elevates the second rib
What is the origin of the middle scalene muscle?
The posterior tubercles of transverse processes of C2-C7
Where does the middle scalene muscle insert?
the 1st rib
What is the main action of the middle scalene muscle
Flexes head laterally; elevates 1st rib
What is the origin of the anterior scalene muscle
Anterior tubercles of transverse processes of C3-C6
Where does the anterior scalene muscle insert?
1st rib
What is the innervation of the anterior scalene muscle
C5-C7
What is the innervation of the middle scalene muscle?
C3-C8
What is the main action of the anterior scalene muscle?
Flexes head laterally; elevates 1st rib
What is the origin of the digastric muscle?
The anterior belly originates from the digastric fossa of the mandible
The posterior belly originates from the mastoid notch
Where does the digastric muscle insert?
In the intermediate tendon to hyoid bone
What is the innervation of the digastric muscle?
The anterior belly is innervated by the mylohyoid nerve, a branch of the inferior alveolar nerve
The posterior belly is innervated by the facial nerve
What are the main actions of the digastric muscle
Depresses the mandible; raises the hyoid bone and steadies it during swallowing and speaking
What is the origin of the sternohyoid muscle?
the manubrium of the sternum and medial end of the clavicle