Biology 213 - 04-12-24 | Quizlet

Central nervous system

brain and spinal cord

Branches of the CNS

sympathetic, parasympathetic

Peripherical nervous system

Includes all of the neurons that are not in the central nervous system

Branches of the PNS

somatic and autonomic

Afferent

sensory, input

Efferent

motor, output

Myelin sheets

myelin sheets wrap around axons and provide an insulator that surrounds most of the nerve and greatly speeds up the messages

Nodes of ranvier

gaps in the myelin sheath

Interneuron

a neuron that carries nerve impulses from one neuron to another

Sensory neurons

conduct signals from receptors to the CNS

Motor neurons

conduct signals from the CNS to effectors such as muscles and glands

Action potential

a neural impulse; a brief electrical charge that travels down an axon

Axon hillock

the cone-shaped area on the cell body from which the axon originates

Sodium-potassium pump

a carrier protein that uses ATP to actively transport sodium ions out of a cell and potassium ions into the cell

Reuptake

endocytosis

Synaptic cleft

The narrow gap that separates the presynaptic neuron from the postsynaptic cell

Depolarization...

is the start of membrane potential and it summed at axon hillock

Refractory period

a period of inactivity after a neuron has fired