Cervical Plexus | Formation, Branches, Communicating Branches | Ansa Cervicalis| скачать в хорошем качестве

Cervical Plexus | Formation, Branches, Communicating Branches | Ansa Cervicalis|

FORMATION The cervical plexus is formed by the ventral rami of the upper four cervical nerves.The rami emerge between the anterior and posterior tubercles of the cervical transverse processes, grooving the costotransverse bars. The four roots are connected with one another to form three loops Position and Relations of the Plexus The plexus is related: 1. Posteriorly, to the muscles which arise from the posterior tubercles of the transverse processes, i.e. the levator scapulae and the scalenus medius. 2. Anteriorly, to the prevertebral fascia, the internal jugular vein and the sternocleidomastoid. Branches Superficial or cutaneous branches 1. Lesser occipital (C2) 2. Great auricular (C2, C3) 3. Transverse (anterior) cutaneous nerve of the neck (c2, c3) 4. Supraclavicular (C3, C4) Deep Branches 1. Grey rami pass from the superior cervical ganglion to the roots of C1-C4 nerves. 2. A branch from C1 joins the hypoglossal nerve and carries fibres for supply of the thyrohyoid and geniohyoid muscles (directly) and the superior belly of the omohyoid through the ansa cervicalis. 3. A branch from C2 to the sternocleidomastoid and branches from C3 and C4 to the trapezius communicate with the accessory nerve Muscular Branches Muscles supplied solely by cervical plexus: 1. Rectus capitis anterior from C1. 2. Rectus capitis lateralis from C1, C2. 3. Longus capitis from C1- C3. 4. Lower root of ansa cervicalis (descendens cervicalis) from C2, C3 (to sternohyoid, sternothyroid andinferior belly of omohyoid. Muscles supplied by cervical plexus along with the brachial plexus or the spinal accessory nerve: a. Sternocleidomastoid from C2 along with accessory nerve. b. Trapezius from C3, C4 along with accessory nerve. c. Levator scapulae from C3, C4 with C5 (dorsal scapular nerve). d. Phrenic nerve from C3, C4, C5. e. Longus colli from C3-C8. f. Scalenus medius from C3-C8. g. Scalenus anterior from C4-C6. h. Scalenus posterior from C6-C8. Ansa Cervicalis This is a thin nerve loop that lies embedded in the anterior wall of the carotid sheath over the lower part of the larynx. It supplies the infrahyoid muscles Formation It is formed by a superior and an inferior root. The superior root is the continuation of the descending branch of the hypoglossal nerve. Its fibres are derived from the first cervical nerve. This root descends over the internal carotid artery and the common carotid artery. The inferior root or descending cervical nerve is derived from second and third cervical spinal nerves. As this root descends, it winds round the internal jugular vein, and then continues anteroinferiorly to join the superior root in front of the common carotid artery Distribution Superior root: To the superior belly of the omohyoid. Ansa cervicalis: To the sternohyoid, the sternothyroid and the inferior belly of the omohyoid. Note that the thyrohyoid and geniohyoid are supplied by separate branches from the first cervical nerve through the hypoglossal nerve ---------------------------------------------------------------------------------------------------------------- My website - https://human-anatomy-lessons.busines... ---------------------------------------------------------------------------------------------------------------- Follow me in blogspot - https://human-anatomylessons.blogspot... _________________________________________________________________________________________________________________ Visit my blogs - https://humananatomyonline.in/ Contact me @ https://t.me/humananatomylessons