Nervous System and Neurons

In a man, if abducens nerve is injured, then movement of the eyeball is affected as it controls the movement of a single muscle, the lateral rectus muscle of the eye.

It encircles the gray matter of spinal cord. It bears nerve processes ascending and descending the spinal cord. The white colour comes from fatty myelin sheath.

It is the space between the arachnoid and the pia mater. It accomodates the cerebrospinal fluid and spider web-like filaments.

It is a longitudinal midline fissure situated on the ventral surface of the spinal cord. The anterior spinal artery is found in this fissure.

The spinal nerves C1 - T1  together form a branch of the nervous system called the brachial plexus. This plexus infuses the muscles of the upper extremity including, all superficial muscles of the back, the entire arm and forearm and hand for that matter.

This ligament lies in the vertebral column. It is broader at the intervertebral discs and narrow at the vertebral bodies. It is not penetrated by the needle during spinal tap.

Neurotrophins are small proteins secreted in the nervous system at extremely low concentration. Low levels of a neurotrophin are needed to keep nerve cells alive. However, in some cases, presence of a neurotrophin can have the opposite effect by initiating cell death. During the development of nervous system, the levels of neurotrophins can control the unwanted nerve cells.

Fatigue is a state of awareness describing a range of afflictions usually associated with physical and/or mental weakness though varying from a general state of lethargy to a specific work induced burning sensation within one's muscles.

The white matter on each side of the spinal cord is organised into three large areas or funiculi. Each funiculus of the spinal cord is comprised of bundles of fibers that run together and subserve the same function.

It is the supportive tissue of the nervous system including the network of branched cells in the central nervous system (astrocytes, microglia, and oligodendrocytes) and the supporting cells of the peripheral nervous system (neurilemma and satellite cells).

The primary lipid of myelin is a glycolipid called galactocerebroside. A galactocerebroside or galactosylceramide is a type of cerebroside consisting a ceramide with a galactose residue at the 1-hydroxyl moiety. Galactocerebroside is a marker for oligodendrocytes in the brain whether or not they form myelin.

Interneuron is a nerve cell found entirely within the central nervous system that acts as a link between sensory neurons and motor neurons.

Glial cells sometimes called neuroglia are non neuronal cells that maintain homeostasis, form myelin, and provide support and protection for neurons in the brain.

Schwann cells are the peripheral nervous system's analogues of the central nervous system's oligodendrocytes.

Nerve fibres vary in size from 0.5 to 20µm in diameter, the smallest unmyelinated fibre being the slowest conducting and the largest myelinated fibres the fastest conducting.