Chapter 7 mega review 2 Flashcards
The cellular unit of the nervous system is the neuron. What is the major function of this type of cell
Neurons are highly specialized to transmit messages (nerve impulses) from one part of the body to another
Central nervous system
the brain and spinal cord collectively
Synapse
junction or point of close contact between neurons
Ganglion
a bundle of nerve processes outside the central nervous system
Association neuron (interneuron)
neuron connecting sensory and motor neurons
PNS
spinal and cranial nerves and ganglia
Nuclei
collections of nerve cell bodies inside the CNS
Efferent neurons
neuron that conducts impulses away from the CNS to muscles and glands
Afferent neuron
neuron that conducts impulses toward the CNS from the body periphery
Neurotransmitter
chemicals released by axon terminals
Which part of the neuron is the axon?
An axon is a long, tail-like structure which joins the cell body at a specialized junction called the axon hillock. Many axons are insulated with a fatty substance called myelin. Myelin helps axons to conduct an electrical signal. Neurons generally have one main axon.
Where is the nucleus of an axon located?
The nucleus is in the cell body (soma)
What are the gaps between Schwann cells called?
Nodes of ranvier
What is the function of the axon terminal?
Axons branch profusely at their terminal end, forming hundreds to thousands of axon terminals; contain hundreds of vesicles that contain neurotransmitters
What is the function of the dendrite?
Dendrites are neuron processes that convey impulses toward the cell body
What is the function of the schwann cell?
Schwann cells envelop part of an axon, deposits myelin around small segments of the nerve fiber
What is the metabolic center of the neuron?
Cell body
What is a reflex?
A reflex is a rapid, predictable, and involuntary response to stimuli
Name the 5 essential components to the reflex arc.
Sensory receptor
Effector organ
Sensory neuron
Motor neuron
Synapse between the sensory and motor neurons : CNS integration center
In general, what is the importance of reflex testing in a routine physical examination?
To determine the general health of the motor portion of the nervous system
What is irritability?
The ability to respond to a stimulus
What is conductivity?
The ability to transmit an electrical impulse