Is the nerve a connective tissue

nerve

from Latin: nervus - tendon, nerve
Synonym: nerve
English: nerve

1 definition

As nerve is an anatomical structure that serves to conduct the excitation. A nerve consists of a multitude of bundled nerve fibers and the connective tissue that surrounds them.

2 anatomy

Nerves are usually systematically named after their main structure (e.g. ulnar nerve) or their supply area (e.g. medial cutaneous nerve, facial nerve), but sometimes also according to anatomical features (e.g. vagus nerve). As they run through the body, they branch out and release fiber bundles to neighboring structures, which are also addressed as a distinct nerve (nerve) or as a branch (ramus). Branches that create fiber connections between two neighboring nerves are called rami communicantes or nerve anastomoses.

In the area of ​​the origins of the extremities, nerves also exchange fibers to a greater extent, thereby forming plexuses (plexuses).

3 histology

Nerves can be further differentiated histologically. The connective tissue involved in the structure of the nerve is divided into 3 zones:

3.1 Endoneurium

The endoneurium is the loose connective tissue that surrounds the Schwann cells of the individual nerve fibers. It contains numerous small blood and lymph vessels that feed the Schwann cells and thus also the nerve fibers they encase. Free cells (e.g. macrophages) are also found occasionally.

3.2 Perineurium

The perineurium is a tight connective tissue that combines many individual nerve fibers into common bundles, the so-called fascicles. It supports and subdivides ("septate") the nerve - comparable to the plastic core of a multi-core cable. The connective tissue cells are in close, epithelial-like contact with one another and are connected to one another by so-called tight junctions.

3.3 Epineurium

The epineurium surrounds the nerve together with the larger vessels supplying it to the outside. It is a connective tissue with numerous collagen fibers, to which an additional "shifting layer" of loose connective tissue or fatty tissue, the so-called mesoneurium, can be attached.

4 classification

4.1 ... according to function

According to the function of the fiber qualities running in them, a distinction is made:

4.2 ... according to topography

A distinction is made according to their origin:

5 clinic

The inflammation of a nerve is called neuritis. Depending on the number of nerves affected, a distinction is made: