Knowra Peripheral nervous system Peripheral nervous system The peripheral nervous system comprises nerves and ganglia outside the brain and spinal cord. It carries sensory information to the central nervous system and motor commands to the body.
Cranial nerves : Twelve pairs of nerves that emerge directly from the brain or brainstem and serve the head, neck, and some internal organs. They connect the brain directly to sensory and motor targets, bypassing the spinal cord.
Autonomic nervous system : The nervous system division that regulates involuntary functions of organs, glands, and smooth and cardiac muscle. It carries peripheral commands that adjust organ activity without deliberate control.
Peripheral neuropathy : A condition in which disease or injury damages nerves outside the brain and spinal cord. It is a broad clinical consequence of dysfunction in the system.
Central nervous system : The brain and spinal cord, which integrate information and coordinate nervous system activity. It is the anatomical counterpart; the boundary between the two divisions lies at the brain and spinal cord.
Spinal nerves : Thirty-one pairs of nerves formed by the joining of sensory and motor roots from the spinal cord. They provide the principal nerve routes between the spinal cord, trunk, and limbs.
Sensory neuron : A neuron that carries information from sensory receptors toward the central nervous system. Sensory neurons relay signals from peripheral receptors into the brain and spinal cord.
Guillain–Barré syndrome : An acute immune-mediated disorder in which the immune system attacks peripheral nerves, often causing weakness and altered sensation. This syndrome shows how immune injury to peripheral nerves can rapidly impair movement.
Sympathetic nervous system : A division of the autonomic nervous system that mobilizes bodily resources during stress and activity. Its characteristic arousal responses distinguish one autonomic pathway within the system.
Ganglion : A cluster of neuronal cell bodies located outside the central nervous system. Ganglia house peripheral neuron cell bodies, including sensory and autonomic neurons.
Motor neuron : A neuron that carries commands from the central nervous system to muscles or glands. Motor neurons deliver central commands to peripheral effectors.
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