What causes myelinated nerve fiber layer?

Published by Charlie Davidson on

What causes myelinated nerve fiber layer?

Myelinated nerve fiber layer (mNFL) is a benign clinical entity that results from an embryologic developmental anomaly whereby focal areas of the retinal nerve fiber layer fail to lose their myelin sheath. Clinically, mNFL appears as distinct white patches on the inner retinal surface.

What nerve fibers types are myelinated?

Nerve fibers are classed into three types – group A nerve fibers, group B nerve fibers, and group C nerve fibers. Groups A and B are myelinated, and group C are unmyelinated. These groups include both sensory fibers and motor fibers.

When nerve fibers are myelinated they appear?

Myelinated retinal nerve fibres (MRNF) are rare congenital anomalies that appear as grey-white opaque lesions on the retina with feathery edges that obscure retina details. They may be located on the disc or elsewhere on the retina. However, few reports of acquired cases have been documented.

What do myelinated fibers consist of?

The peripheral myelinated nerve fiber (Fig. 3-8) consists of a single continuous neuronal process, the axon, and a set of Schwann cells arranged serially along the outside of the axon.

What does the nerve Fibre layer do?

The sparing of this layer is important in the treatment of the disease as it is the basis for connecting retinal prostheses to the optic nerve, or implanting stem cells that could regenerate the lost photoreceptors. RNFL is a sensitive structure. Some process can excites its natural apoptosis.

What color is myelinated nerve fibers?

Myelin gives the white matter its color. It also protects the nerve fibers from injury. Also, it improves the speed and transmission of electrical nerve signals along extensions of the nerve cells called axons. By comparison, gray matter is tissue found on the surface of the brain (cortical).

Where are Unmyelinated nerve fibers found?

Unmyelinated fibers, being widely distributed, are found in both hairy and glabrous skin. Mechanoafferent C tactile fibers are found in hairy skin, associated with hair follicles. These are also present in the glabrous skin of the glans penis and glans clitoris.

What do you call Unmyelinated fibers?

Unmyelinated, also called type C, fibers include both nonpeptidergic (for mechanical sensitivity) and peptidergic (for heat/cold sensitivity) C-fiber axons. They lack the myelin envelope completely, with Schwann cells surrounding them forming the Remak fibers in bundles within peripheral nerves.

What is normal nerve fiber layer thickness?

Mean RNFL thickness (360° measurement) ranged from 40 to 105 µm in OHT eyes, from 46 to 106 µm in normal eyes, and from 4 to 85 µm in glaucomatous eyes.

Categories: Helpful tips