Nervous system

Coccygeal plexus

The coccygeal plexus (plexus coccygeus) is formed by the fibers of the anterior branches of the fourth and fifth sacral (SIV-V) and the anterior branch of the coccygeal (CoI) spinal nerves.

The intercostal nerves (nn. intercostales) are directed laterally and forward in the intercostal spaces, the subcostal nerve - under the 12th rib. Each intercostal nerve passes at the lower edge of the corresponding rib under the artery and vein of the same name.

Radial nerve

The radial nerve (n. radialis) is a continuation of the posterior cord of the brachial plexus. It consists of fibers of the anterior branches of the fifth cervical - first thoracic (CV-ThI) spinal nerves. In terms of thickness, the radial nerve is the largest branch of the brachial plexus.

The ulnar nerve

The ulnar nerve (n. ulnaris) originates from the medial cord of the brachial plexus. It consists of fibers of the anterior branches of the eighth cervical - first thoracic (CVIII-ThI) spinal nerves.

Median nerve

The median nerve (n. medianus) originates from the junction of the lateral and medial bundles of the brachial plexus formed by the fibers of the anterior branches of the sixth to eighth cervical and first thoracic (CVI-ThI) spinal nerves.

Brachial plexus

The brachial plexus (plexus brachialis) is formed by the anterior branches of the four lower cervical (CV-CVIII) spinal nerves. The plexus is divided by topographic features into supraclavicular and infraclavicular parts (pars supraclavicularis et pars infraclavicularis).

Cervical plexus

The cervical plexus (plexus cervicales) is formed by the anterior branches of the four upper cervical (CI-CIV) spinal nerves.

Spinal nerves

Spinal nerves (n. spinales) are paired, metamerically located nerve trunks. A person has 31-33 pairs of spinal nerves: 8 pairs of cervical, 12 pairs of thoracic, 5 pairs of lumbar, 5 pairs of sacral and 1-3 pairs of coccygeal, corresponding to 31-33 segments of the spinal cord.

Hyoid nerve

The hypoglossal nerve (n. hypoglossus), formed by fibers of the motor nucleus, innervates the muscles of the tongue and some muscles of the neck. The nerve leaves the brain in the groove between the pyramid and the olive, and is directed forward and laterally into the hypoglossal canal of the occipital bone.

Accessory nerve

The accessory nerve (n. accessories), or nerve of Willis, is formed by the processes of the motor nuclei located in the tegmentum of the medulla oblongata and in the spinal cord.

Health