Chapter 9 Anatomy Study Guide
Terms in this set (22)
Branchlike parts of a neuron that are specialized to receive information.
a nerve cell; the basic building block of the nervous system
Cone shaped region of an axon where it joins the cell body.
a neural impulse; a brief electrical charge that travels down an axon
All or Nothing Process
the action potential either fires completely or not at all
the extension of a neuron, ending in branching terminal fibers, through which messages pass to other neurons or to muscles or glands
knoblike structures that branch out from an axon
tiny spaces between neurons
a fatty substance that helps insulate neurons and speeds the transmission of nerve impulses
Nodes of Ranvier
gaps in the myelin sheath
many extensions from the cell body
A neuron that has only two projections (one axon/one dendrite) from the cell body
have a short single process leaving the cell body
Neurons and nerve cells are the same.
All neurons only have one axon.
False; they can have 0 or 1
All neurons only have one dendrite
Neurons touch each other.
Axons are very short and not long at all.
Explain what characteristic an axon must have to speed up an impulse.
The presence of myelin which insulates the electrical potential and the diameter of the axon. The greater the diameter the faster the rate of impulse conduction.
Explain the difference between electrical and chemical impulses.
In a chemical synapse, the nerve impulse passes chemically through neurotransmitters. In an electrical synapse, the nerve impulse passes through through channel proteins