node of Ranvier
Axonal insulation break
A node of Ranvier is a gap in the myelin sheath surrounding a nerve fiber, where the axon membrane is exposed.
These regularly spaced nodes allow nerve impulses to jump from gap to gap rather than traveling continuously, dramatically speeding signal transmission.
Named for French anatomist Louis-Antoine Ranvier.
Impulse jumping between myelin gaps
- action potentialNeuron's rapid electrical discharge
- depolarizationLoss of electrical gradient
- repolarizationMembrane voltage reset
- nerve impulseElectrical signal through neurons
electrical transmission · current flow · threshold potential · excitability
Lipid layer around axons
- demyelinationNerve sheath degradation
- insulationThermal transfer prevention
Autoimmune demyelinating neurological disease
- Charcot-Marie-ToothInherited motor-sensory neuropathy
- nerve damageInjured neural tissue
- neuropathyDamage to peripheral nerves
- lesionArea of pathological change
saltatory conduction
Impulse jumping between myelin gaps
- action potentialNeuron's rapid electrical discharge
- depolarizationLoss of electrical gradient
- repolarizationMembrane voltage reset
nerve impulse · electrical transmission · current flow · threshold potential · excitability
myelin sheath
Lipid layer around axons
- demyelinationNerve sheath degradation
- insulationThermal transfer prevention
multiple sclerosis
Autoimmune demyelinating neurological disease
- Charcot-Marie-ToothInherited motor-sensory neuropathy
- nerve damageInjured neural tissue
- neuropathyDamage to peripheral nerves
potassium channels
Membrane proteins selective for K⁺
internode
Stem section between nodes
- segmentationDivision into sections
- neuroscienceneuron, MRI, brain, neurons, synapses
- Neurophysiologyneuron, action potential, neurotransmitter, nerve impulse, presynaptic
- brain anatomybrain, cerebrum, cerebellum, brainstem, cortex
- gliaastrocyte, astrocytes, microglia, neuroglia, radial glia