peripheral nervous system
Nerves beyond brain
The peripheral nervous system is the network of nerves outside the brain and spinal cord.
It connects the central nervous system to the rest of the body—carrying sensory information inward and motor commands outward to muscles and glands.
The peripheral nervous system includes cranial nerves, spinal nerves, and the autonomic nervous system that regulates involuntary functions like heartbeat and digestion.
Masses of nerve tissue
- axonsNeuron output extensions
- dendritesNeuron's signal-receiving projections
- myelin sheathLipid layer around axons
- plexusInterwoven network of vessels
Damage to peripheral nerves
- neuralgiaSharp pain from irritated nerves
- carpal tunnelWrist's nerve passageway
- sciaticaLumbar nerve inflammation
- Guillain-BarréAutoimmune peripheral neuropathy
tingling · weakness · Bell's palsy · shingles · Charcot-Marie-Tooth · demyelination · paresthesia · radiculopathy
Perceiving through physical contact
- painBodily or emotional distress
- temperatureMeasured heat intensity
- pressureForce upon contact
- proprioceptionBody's spatial self-awareness
sensory receptors · vibration · itch · tingle · numbness · stimuli · Meissner corpuscles · Pacinian corpuscles
Contractile body tissue
- acetylcholineNeurotransmitter for muscles and memory
- muscle contractionFibers tensing and shortening
- coordinationOrganized cooperative movement
- locomotionAbility to travel independently
reflex arc · skeletal muscle · muscle tone · voluntary movement · stretch reflex
Feeling others' emotions
- parasympatheticNerve system promoting rest
- fight-or-flightAcute threat reaction
- adrenalineEmergency response hormone
- norepinephrineAlertness and stress hormone
heart rate · digestion · pupil dilation · vasoconstriction · bronchodilation · stress response · homeostasis · smooth muscle
ganglia
Masses of nerve tissue
- axonsNeuron output extensions
- dendritesNeuron's signal-receiving projections
- myelin sheathLipid layer around axons
plexus · neuroglia · interneurons · nodes of Ranvier · dermatome
neuropathy
Damage to peripheral nerves
- neuralgiaSharp pain from irritated nerves
- carpal tunnelWrist's nerve passageway
- sciaticaLumbar nerve inflammation
Guillain-Barré · tingling · weakness · Bell's palsy · shingles · Charcot-Marie-Tooth · demyelination · paresthesia · radiculopathy
touch
Perceiving through physical contact
- painBodily or emotional distress
- temperatureMeasured heat intensity
- pressureForce upon contact
proprioception · sensory receptors · vibration · itch · tingle · numbness · stimuli · Meissner corpuscles · Pacinian corpuscles · referred pain
muscles
Contractile body tissue
- acetylcholineNeurotransmitter for muscles and memory
- muscle contractionFibers tensing and shortening
- coordinationOrganized cooperative movement
locomotion · reflex arc · skeletal muscle · muscle tone · voluntary movement · stretch reflex
sympathetic
Feeling others' emotions
- parasympatheticNerve system promoting rest
- fight-or-flightAcute threat reaction
- adrenalineEmergency response hormone
norepinephrine · heart rate · digestion · pupil dilation · vasoconstriction · bronchodilation · stress response · homeostasis · smooth muscle · cardiac muscle
peripheral nervous systemcentral nervous system
Brain plus spinal cord
CNS · brain · spinal cord
peripheral, periphery, peripherally, peripherals, nervous, nerve, nerves, nervously, nervousness