CERVICAL plexus

Question 1

location

Answer 1

1. The cervical plexus lies anteromedial to the levator scapulae and middle scalene muscles and deep to the
   SCM
2. It is located in the posterior triangle of the neck, halfway up the sternocleidomastoid muscle, and within the prevertebral layer of cervical fascia. The plexus is formed by the anterior rami (divisions) of cervical spinal nerves C1-C4.

Question 2

Each nerve then divides into anterior and posterior nerve fibers. The cervical plexus begins as the anterior fibers of the spinal nerves C1, C2, C3, and C4.

Answer 2

true

Question 3

After arising from the cervical plexus, the muscular branches tend to travel initially in an anteromedial direction. This is in contrast to the cutaneous branches, which travel posteriorly

Answer 3

true

Question 4

Muscular Branches-phrenic nerve

Answer 4

The phrenic nerves originate chiefly from the C4 nerve but receive contributions from the C3 and C5
nerves. The phrenic nerves contain motor, sensory, and sympathetic nerve fibres. These nerves provide the
sole motor supply to the diaphragm as well as sensation to its central part.

Question 5

Muscular Branches-nerves to Geniohyoid and Thyrohyroid

Answer 5

The C1 spinal nerve gives rise to nerves to the geniohyoid (moves the hyoid bone anteriorly and upwards, expanding the airway) and the thyrohyoid (which depresses the hyoid bone and elevates the larynx).

These nerves travel with the hypoglossal nerve to reach their respective muscles.

Question 6

Muscular Branches-Ansa Cervicalis

Answer 6

The ansa cervicalis is a loop of nerves, formed by nerve roots C1-C3. It gives off four muscular branches:

Superior belly of the omohyoid muscle
Inferior belly of the omohyoid muscle
Sternohyoid
Sternothyroid
These muscles (the infrahyoid) act to depress the hyoid bone; an important function for swallowing and speech.

Question 7

The fourth infrahyoid muscle, the thyrohyoid, receives C1 fibers, which descend
independently from the hypoglossal nerve

Answer 7

true

Question 8

Sensory Branches- greater auricular nerve

Answer 8

The greater auricular nerve is formed by fibres from C2 and C3 roots. It provides sensation to the external ear and the skin over the parotid gland. It is the largest ascending branch of the plexus.

The nerve also communicates with the auricular branch of the vagus nerve and the posterior auricular branch of the facial nerve (which innervates some small muscles around the ear).

Question 9

Sensory Branches- lesser occipital nerve

Answer 9

1. Supplies the skin of the neck and scalp posterosuperior to the auricle
2. The lesser occipital nerve is derived from the C2 root, with a contribution from C3 in some individuals. It supplies cutaneous sensation to the posterosuperior scalp, and commonly communicates with the posterior branch of the greater auricular nerve.

After its formation, the nerve curves around the accessory nerve, and passes superiorly, close to the posterior border of the sternocleidomastoid.

Question 10

Sensory Branches- transverse cervical nerve

Answer 10

1. (C2 and C3): supplies the skin covering the anterior cervical region
2. The nerve then pierces the deep cervical fascia and then gives branches that pass superiorly and inferiorly to supply the anterolateral skin of the neck and upper sternum

Question 11

Sensory Branches-sternoclavicular nerve

Answer 11

1. Supraclavicular nerves (C3 and C4): Supplies the skin over the shoulder
2. and provide sensation to the skin overlying the supraclavicular fossa and upper thoracic region and sternoclavicular joint

Question 12

where do the sensory branches of the cervical plexus enter the skin?

Answer 12

middle of the posterior border of the sternocleidomastoid muscle