SOLUTIONS TO EXERCISES, LESSON 12
The neuron is also called a nerve cell. It is the conducting unit of the nervous
system. It is specialized to be irritable and transmit signals, or impulses. (para 12-1)
The three major subdivisions of the human nervous system are the central
nervous system, the peripheral nervous system, and the autonomic nervous system.
A neuron is the nerve cell body plus all of its processes and coverings.
A nerve is a collection of neuron processes together and outside of the CNS.
A fiber tract is a collection of neuron processes together and within the CNS.
A ganglion is a collection of nerve cell bodies together and outside of the CNS.
A nucleus is a collection of nerve cell bodies together and within the CNS.
The human nervous system is supplied with special junctions called synapses.
In general terms, the human nervous system can be compared to a computer.
Sensory information is the input, which is collated along with previously stored
information. Once a decision has been reached by the central portion, there is an
output of commands to the effector organs (muscles and/or glands). (para 12-4b)
The brainstem is a primary coordinating center of the human nervous system.
The cerebellum is the primary coordinating center for muscle actions. Here,
patterns of movement are properly integrated. Also, the cerebellum is very much
The newest development of the brain is the cerebrum. (para 12-6)
The autonomic nervous system (ANS) is that portion of the nervous system
concerned with commands for smooth muscle tissue, cardiac muscle tissue, and
For most of us, the control of the visceral organs is automatic, that is, without