The human body consists of two nervous systems: Central Nervous System (CNS) and Peripheral Nervous System (PNS). The CNS consists of the brain and the spinal cord, whereas, the PNS consists of nerves outside the brain and spinal cord. The PNS connects the rest of the body to the CNS. The PNS are grouped into two categories, sensory (afferent) nerves and motor (efferent) nerves. Sensory nerves convey information from receptors to the CNS. Motor nerves convey information from the CNS to the muscles and the rest of the body. The motor (efferent) nerves are further divided into two; somatic system (voluntary control) and autonomic system (involuntary control). (Fig. 1: Microscopic images of nerve cells and axons.)
Nerves convey messages …show more content…
Damage to the spinal for, for example is far more serious and difficult to treat than an injury in the radial nerve. Axons in the PNS readily and automatically regenerate which means that entire function recovery is possible after the severing of the nerve. This is due to the presence of “(…) both growth-promoting factors in the PNS and growth-inhibiting factors in the CNS.” (Huebner, Strittmatter, 2009). Following the severing or crushing of a nerve in the PNS, the nerve will begin to undergo Wallerian Degeneration, which is the process where the nerve ending that is separated from the system begins to degenerate. Once the injury has occurred, it takes around 24 hours in the PNS to begin Wallerian Degeneration. First, the axonal skeleton and membrane disintegrate. Following this, the myelin sheath is disintegrated and macrophages and Schwann cells (glial cells which support neurons) enter the neurolemma, which remains as a hollow tube following the disintegration of the …show more content…
4: Wallerian Degeneration process.)
Following the severing or cutting of the nerve, the PNS neurons begin to increase the production of “(…) numerous regeneration-associated genes.” These genes encourage the nerve fibre to reform within the hollow neurolemma, which is a process that could take anywhere from several months to years.
Recently, University of Texas Professor George Bittner has discovered a new method for non-surgical nerve regeneration. Previously, it was assumed that the regeneration of the selective-barrier around the axolemma was necessary for the nerve regeneration process to begin however, Bittner, through testing on earthworms and crayfish, found that by covering the ends of the severed axons in a calcium free solution, the nerve repair process in terminated and the selective barrier is not constructed around the axons. Following this, the axons are brought close together and after removing the water from the membranes, the plasma membranes are merged.
Nerves convey messages …show more content…
Damage to the spinal for, for example is far more serious and difficult to treat than an injury in the radial nerve. Axons in the PNS readily and automatically regenerate which means that entire function recovery is possible after the severing of the nerve. This is due to the presence of “(…) both growth-promoting factors in the PNS and growth-inhibiting factors in the CNS.” (Huebner, Strittmatter, 2009). Following the severing or crushing of a nerve in the PNS, the nerve will begin to undergo Wallerian Degeneration, which is the process where the nerve ending that is separated from the system begins to degenerate. Once the injury has occurred, it takes around 24 hours in the PNS to begin Wallerian Degeneration. First, the axonal skeleton and membrane disintegrate. Following this, the myelin sheath is disintegrated and macrophages and Schwann cells (glial cells which support neurons) enter the neurolemma, which remains as a hollow tube following the disintegration of the …show more content…
4: Wallerian Degeneration process.)
Following the severing or cutting of the nerve, the PNS neurons begin to increase the production of “(…) numerous regeneration-associated genes.” These genes encourage the nerve fibre to reform within the hollow neurolemma, which is a process that could take anywhere from several months to years.
Recently, University of Texas Professor George Bittner has discovered a new method for non-surgical nerve regeneration. Previously, it was assumed that the regeneration of the selective-barrier around the axolemma was necessary for the nerve regeneration process to begin however, Bittner, through testing on earthworms and crayfish, found that by covering the ends of the severed axons in a calcium free solution, the nerve repair process in terminated and the selective barrier is not constructed around the axons. Following this, the axons are brought close together and after removing the water from the membranes, the plasma membranes are merged.