No Results Found!
538 Related Articles

Nervous system

neuralnervousneurogenic
The peripheral nervous system (PNS) is one of two components that make up the nervous system of bilateral animals, with the other part being the central nervous system (CNS).
In vertebrates it consists of two main parts, the central nervous system (CNS) and the peripheral nervous system (PNS).

Nerve

nervesinnervationinnervated
The PNS consists of the nerves and ganglia outside the brain and spinal cord.
A nerve is an enclosed, cable-like bundle of nerve fibres called axons, in the peripheral nervous system.

Central nervous system

CNScentralcentral nervous system (CNS)
The peripheral nervous system (PNS) is one of two components that make up the nervous system of bilateral animals, with the other part being the central nervous system (CNS).
Microscopically, there are differences between the neurons and tissue of the CNS and the peripheral nervous system (PNS).

Somatic nervous system

somaticsomatomotorvoluntary
The peripheral nervous system is divided into the somatic nervous system and the autonomic nervous system.
The somatic nervous system (SNS or voluntary nervous system) is the part of the peripheral nervous system associated with the voluntary control of body movements via skeletal muscles.

Autonomic nervous system

autonomicautonomous nervous systemautonomic functions
The peripheral nervous system is divided into the somatic nervous system and the autonomic nervous system.
The autonomic nervous system (ANS), formerly the vegetative nervous system, is a division of the peripheral nervous system that supplies smooth muscle and glands, and thus influences the function of internal organs.

Spinal cord

medulla spinalisspinethoracic segment
The PNS consists of the nerves and ganglia outside the brain and spinal cord.
The spinal cord is the main pathway for information connecting the brain and peripheral nervous system.

Cranial nerves

cranial nervecranialCN
In the somatic nervous system, the cranial nerves are part of the PNS with the exception of the optic nerve (cranial nerve II), along with the retina.
The cranial nerves are considered components of the peripheral nervous system (PNS), although on a structural level the olfactory (I), optic (II), and trigeminal (V) nerves are more accurately considered part of the central nervous system (CNS).

Axon

axonsnerve fiberaxonal
However, the remaining ten cranial nerve axons extend beyond the brain and are therefore considered part of the PNS.
In certain sensory neurons (pseudounipolar neurons), such as those for touch and warmth, the axons are called afferent nerve fibers and the electrical impulse travels along these from the periphery to the cell body, and from the cell body to the spinal cord along another branch of the same axon.

Ganglion

gangliaganglion cellspreganglionic neurons
The PNS consists of the nerves and ganglia outside the brain and spinal cord.
Ganglia provide relay points and intermediary connections between different neurological structures in the body, such as the peripheral and central nervous systems.

Vertebral column

spinespinal columnspinal
Unlike the CNS, the PNS is not protected by the vertebral column and skull, or by the blood–brain barrier, which leaves it exposed to toxins and mechanical injuries.
The spinal cord is part of the central nervous system that supplies nerves and receives information from the peripheral nervous system within the body.

Optic nerve

optic nervesoptical nerveoptic
In the somatic nervous system, the cranial nerves are part of the PNS with the exception of the optic nerve (cranial nerve II), along with the retina.
The optic nerve has been classified as the second of twelve paired cranial nerves but it is technically part of the central nervous system, rather than the peripheral nervous system because it is derived from an out-pouching of the diencephalon (optic stalks) during embryonic development.

Muscle

musclesmuscularmusculature
The somatic nervous system is under voluntary control, and transmits signals from the brain to end organs such as muscle s. The sensory nervous system is part of the somatic nervous system and transmits signals from senses such as taste and touch (including fine touch and gross touch) to the spinal cord and brain.
The efferent leg of the peripheral nervous system is responsible for conveying commands to the muscles and glands, and is ultimately responsible for voluntary movement.

Blood–brain barrier

blood-brain barrierblood brain barrierblood-brain-barrier
Unlike the CNS, the PNS is not protected by the vertebral column and skull, or by the blood–brain barrier, which leaves it exposed to toxins and mechanical injuries.
Multiple sclerosis (MS) is considered to be an auto-immune and neurodegenerative disorder in which the immune system attacks the myelin that protects and electrically insulates the neurons of the central and peripheral nervous systems.

Spinal nerve

spinal nervescervical nervessacral nerves
For the rest of the body, spinal nerves are responsible for somatosensory information.
The spinal nerves are part of the peripheral nervous system.

Sensory nervous system

sensory systemsensorysensory organ
The somatic nervous system is under voluntary control, and transmits signals from the brain to end organs such as muscle s. The sensory nervous system is part of the somatic nervous system and transmits signals from senses such as taste and touch (including fine touch and gross touch) to the spinal cord and brain.
Unique to the olfactory and gustatory systems, at least in mammals, is the implementation of both peripheral and central mechanisms of action.

Parasympathetic nervous system

parasympatheticparasympathetic nerveparasympathetic nerves
The connection between CNS and organs allows the system to be in two different functional states: sympathetic and parasympathetic. Primarily using the neurotransmitter acetylcholine (ACh) as a mediator, the parasympathetic system allows the body to function in a “rest and digest” state.
The parasympathetic nervous system (PSNS) is one of the two divisions of the autonomic nervous system (a division of the peripheral nervous system (PNS)), the other being the sympathetic nervous system.

Anatomical terms of location

ventraldorsalanterior
Examples of the application of the terms are the distinction between central- and peripheral nervous systems, and between peripheral blood vessels and the central circulatory organs, such as the heart and major vessels.

Brachial plexus injury

brachial neuritisBackpack palsybrachial plexopathy
See brachial plexus injuries.
The brachial plexus is made up of spinal nerves that are part of the peripheral nervous system.

Classification of peripheral nerves

The classification of peripheral nerves in the peripheral nervous system (PNS) groups the nerves into two main groups, the somatic and the autonomic nervous systems.

Acetylcholine

cholinergicAChacetylcholine (ACh)
Primarily using the neurotransmitter acetylcholine (ACh) as a mediator, the parasympathetic system allows the body to function in a “rest and digest” state.
Acetylcholine functions in both the central nervous system (CNS) and the peripheral nervous system (PNS).

Nervous tissue

neural tissuenerve tissueConnective tissue in the peripheral nervous system
The nervous system regulates and controls bodily functions and activity and consists of two parts: the central nervous system (CNS) comprising the brain and spinal cord, and the peripheral nervous system (PNS) comprising the branching peripheral nerves.

Preferential motor reinnervation

Preferential motor reinnervation (PMR) refers to the tendency of a regenerating axon in the peripheral nervous system (PNS) to reinnervate a motor pathway as opposed to a somatosensory pathway.

Bilateria

bilaterianbilateriansbilateral animals
The peripheral nervous system (PNS) is one of two components that make up the nervous system of bilateral animals, with the other part being the central nervous system (CNS).

Brain

brain functionmammalian braincerebral
The PNS consists of the nerves and ganglia outside the brain and spinal cord.

Organ (anatomy)

organorgansviscera
The main function of the PNS is to connect the CNS to the limbs and organs, essentially serving as a relay between the brain and spinal cord and the rest of the body.