Cells that serve as the functional units of the nervous system
neurons - they are the nerve cells.
Three basic parts of the neuron
cell body, dendrites, and axoms
what do dendrites do
they receive and relay the nerve impulses TOWARD the cell body.
Which art of the neuron contains the nucleus and cytoplasmic organelles
What do the axoms do
they carry impulses AWAY from the cell body.
longest portion of neuron
axoms of neurons are covered by lipid layer called a
special cells that produce the myelin sheath
Neurons do not touch each other. Junction b/ two neurons that keeps them from touching is...
space b/ axon terminal and neuron is called
electrochemical pulse that moves along the membrane of the neuron
The nerve impulse must cross synaptic cleft by using what...
3 types of neurons
sensory, interneurons, motor neurons
involuntary response to a stimulus...
Explain reflex arc
Sensory neuron in skin is stimulated and impulse is carried to central nervous system. There sensory neuron forms synapse w one or more interneurons. Interneuron passes impulse on to motor neuron which carries impulse to the muscle and a body movement happens. At same time, interneurons send impulse to barin, telling of the stimulus it received. Muscle usually reacts before brain gets the message. So reflex arcs are involuntary.
Brain and spinal cord are covered by three protective coverings called
three type of protective coverings are...
dura mater, arachnoid and pia mater.
describe dura mater
thick tough membrane containing blood vessels
thin, delicate cobweb like membrane
describe pia mater
thin membrane on surface of spinal cord and brain. contains small blood vessels.
fluid b/ pia mater and arachnoid membrane is called
What does the cerebrospinal fluid do
Fills spaces around brain and spinal cord. it nourishes and cushions.
Brain receives how much blood pumped to the heart
Color of brain
Cell bodies and dendrites make up which matter of the brain...white or gray matter
axons and myelin sheaths make up which matter of the brain...white or gray matter