Nervous Overview 6.1.14 Flashcards
CNS =
brain and spinal cord
PNS=
- nerves- carry signals to and from CNS
- ganglia– collection of nerve cell bodies
- sense organs- eye, inner ear,
neuron
nerve cell, has membrane that can conduct electrical impulses
dendrites
input signals
axon
output signals
glia (glue) cells
neurons are surrounded by supporting cells called glia, provide nutrients, some produce myelin
synapse
site of transmission of electrical impulses from nerve cells to other nerve cells, muscle and secretory cells, impulses transmission often occurs by release of chemicals called neurotransmitters at synapse output synapses found at axon terminal
axon terminal
output synapses found here
naming spinal nerves
cervical- above corresponding vertebrae
all others are below
somatic nervous system
considered voluntary, conscious part of nervous system
somatic efferents
control skeletal muscle, voluntary activity
somatic afferents
sensory neurons that innervate skin, joints; provide precise conscious sensation of touch, pressure, pain to skin
also provide sense of body position
dorsal (posterior) horn
(H that goes out)
area that receives signals from sensory axons (somatic and visceral)
Anterior ventral horn
contains neurons that innervate skeletal muscle; these types of neurons are called somatic motor neurons or somatic efferents; axons leave via ventral rootlets.
Lateral Horn
found in thoracic and upper lumbar regions
contains neurons that innervate smooth muscle glands and internal organs. called visceral motor neurons or visceral efferents.
dorsal root
contains afferent sensory axons
dorsal root ganglion
cell bodies of all sensory neurons
ventral root
contains efferent (motor) axons
dermatome
area of skin innervated by single spinal nerve
ended on slide 21
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