Cervical plexus

The cervical plexus ("neck plexus ") is an aggregation of the anterior branches of the first to fourth spinal cord nerves of the neck . As with the other somatic plexuses ( brachial plexus , lumbosacral plexus ), the fibers of the individual spinal nerve segments are exchanged in the cervical plexus . The cervical plexus lies in front of the origins of the scalenus medius muscle and the levator scapulae muscle . He has connections to the hypoglossal nerve , the accessory nerve and sympathetic trunk .

The cervical plexus is divided into superficial sensitive and deep motor branches.

Sensitive part ( Radix sensoria )

The sensitive branches are:

• Lesser occipital nerve
• Magnus auricular nerve
• Transversus colli nerve
• Supraclavicular nerve

The sensitive supply area of ​​these nerves includes the back of the head and the neck. They pierce the neck fascia at the punctum nervosum ( Erb point ). The Erb point lies backwards (dorsal), halfway along the sternocleidomastoid muscle . The nerve fibers fan out after emerging on the fascia (epifascial) cephalad (cranially), forward (anterior) and caudal (caudal) on.

Motor component ( radix motoria )

The nerve branches supplying the skeletal muscles are:

• Phrenic nerve (C3-C5): As the most important branch of the plexus, it innervates the diaphragm . If both sides fail, the diaphragm is elevated, and deep inspiration is then no longer possible.
• Ramus musculi sternocleidomastoidei , supplies the musculus sternocleidomastoideus
• Ramus musculi trapezii , supplies the trapezius muscle
• Ansa cervicalis (often with the addition profunda ) = "neck loop"; Radix superior from C1 and Radix inferior from C2 and C3: It supplies the sub-hyoid muscles. The upper root of the ansa cervicalis lies in its initial part of the XII. Cranial nerves ( hypoglossal nerve ).

The plexus innervates directly with the other rami musculares :

• Musculus levator scapulae (double innervation with the nervus dorsalis scapulae from the plexus brachialis)
• Scalen muscles
• Geniohyoid muscle
• Sub-hyoid muscles (via ansa cervicalis profunda )
• ( prevertebral ) muscles in front of the cervical spine ( Musculus longus colli , Musculus longus capitis and Musculus rectus capitis anterior )

See also

• Dermatome
• Myotome

literature

• Waldeyer: Waldeyer anatomy of man . Walter de Gruyter, 17th ed. 2003, ISBN 9783110165616 , pp. 266-269.