Neuroregeneration differs between the peripheralnervoussystem (PNS) and the central nervoussystem (CNS) by the functional mechanisms and especially by the extent and speed.
The nervoussystem is divided into two parts: the central nervoussystem, which consists of the brain and spinal cord, and the peripheralnervoussystem, which consists of cranial and spinal nerves along with their associated ganglia.
While the peripheralnervoussystem has an intrinsic ability for repair and regeneration, the central nervoussystem is, for the most part, incapable of self-repair and regeneration.
Neuroregeneration in the peripheralnervoussystem (PNS) occurs to a significant degree.
Unlike peripheralnervoussystem injury, injury to the central nervoussystem is not followed by extensive regeneration.
The peripheralnervoussystem is able to repair and regenerate itself, but the central nervoussystem is incapable of doing so.
In vertebrates, the first sign of the nervoussystem is the appearance of a thin strip of cells along the center of the back, called the neural plate.
The inner portion of the neural plate (along the midline) is destined to become the central nervoussystem (CNS), the outer portion the peripheralnervoussystem (PNS).
Neural crest cells are a transient, multipotent, migratory cell population unique to vertebrates that gives rise to a diverse cell lineage including melanocytes, craniofacial cartilage and bone, smooth muscle, peripheral and enteric neurons and glia.
Subsequently, neural crest cells from the roof plate of the neural tube undergo an epithelial to mesenchymal transition, delaminating from the neuroepithelium and migrating through the periphery where they differentiate into varied cell types, including pigment cells and the cells of the peripheralnervoussystem.
The peripheralnervoussystem develops from two strips of tissue called the neural crest, running lengthwise above the neural tube.
ANS The autonomic nervoussystem (ANS or visceral nervoussystem or involuntary nervoussystem) is the part of the peripheralnervoussystem that acts as a control system functioning largely below the level of consciousness and controls visceral functions .
It is classically divided into two subsystems: the parasympathetic nervoussystem (PSNS) and sympathetic nervoussystem (SNS).
The enteric nervoussystem is sometimes considered part of the autonomic nervoussystem, and sometimes considered an independent system.
Regulation of Enteric Function The effect of parasympathetic stimulation is to increase activity in the entire enteric nervoussystem The proximal half of the nervoussystem is innervated from the cranial parasympathetic nerve fibers via the vagal nerve.
Stimulation of the enteric nerves by the sympathetic system inhibits GI activity.
The autonomic nervoussystem is a part of the peripheralnervoussystem that controls visceral functions such as heart rate and digestion.
The peripheralnervoussystem (PNS) consists of the nerves and ganglia outside of the brain and spinal cord .
The main function of the PNS is to connect the central nervoussystem (CNS) to the limbs and organs.
The peripheralnervoussystem is divided into the somatic nervoussystem and the autonomic nervoussystem.
The peripheralnervoussystem includes 12 cranial nerves and 31 pairs of spinal nerves, which provide communication from the CNS to the rest of the body by nerve impulses that regulate the functions of the human body.
The optic nerve is the second of twelve paired cranial nerves but it is considered by physiologists to be part of the central nervoussystem, as it is derived from an outpouching of the diencephalon during embryonic development.
As a consequence, the fibres are covered with myelin produced by oligodendrocytes, rather than Schwann cells, which are found in the peripheralnervoussystem.
The optic nerve is ensheathed in all three meningeal layers (dura, arachnoid, and pia mater) rather than the epineurium, perineurium, and endoneurium found in the peripheral nerves.
Fibre tracks of the mammalian central nervoussystem are incapable of regeneration.
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