12.13.1 The Central and Peripheral Nervous Systems and the Neuron

Question 1

The Central and Peripheral Nervous Systems and the Neuron

Answer 1

• The nervous system is composed of two main parts:
 1. The central nervous system (including the brain and the spinal cord)
 2. The peripheral nervous system
 A. Sensory (input)
 B. Motor (output)
• The components of a neuron include:
 · cell body
 · dendrites
 · axon
 · myelin sheath
 · terminal branches
 · synaptic branches

Question 2

major components of nervous system

Answer 2

• The two major components of the nervous system are:
  · the central nervous system
  · the peripheral nervous system
• The central nervous system consists of the brain and the spinal cord.
• The peripheral nervous system consists of sensory and motor nerves. Sensory nerves receive sensory input; motor nerves deliver motor output.

Question 3

neuron

Answer 3

• Specialized cells called neurons are the functional units of the nervous system. Neurons contain all of the organelles found in a typical eukaryotic cell. They are specialized to conduct sensory information in the form of electrical impulses. The unique structure of neurons allows them to function as conductors of electricity.
• Neurons consist of the following components:
  · cell body
  · dendrites
  · axon
  · myelin sheath
  · terminal branches

Question 4

note

Answer 4

• The cell body contains the nucleus and most of the cell’s organelles. Dendrites are projections that bring information from other neurons or sensory cells to the neuron’s cell body. A long projection that is covered in myelin is called the axon. The myelin sheath is material formed from Schwann cells that insulates the axon, helping to speed up the transmission of a nerve impulse. The axon ends with terminal branches

Question 5

Label the parts of the neuron illustrated below.

Answer 5

i. dendrite
ii. nucleus
iii. axon
iv. synaptic terminal

Question 6

A network of nerves forming the peripheral nervous system carries information from __________ receptors to the central nervous system and __________ receptors from the central nervous system to target glands or organs.

Answer 6

• sensory, motor

Question 7

True or false?

The central nervous system includes the brain, spinal cord, and sensory and motor neurons.

Answer 7

• false

Question 8

The functional unit of the nervous system is the

Answer 8

• neuron

Question 9

The axons of the neuron are encircled by specialized cells called __________, which produce a __________.

Answer 9

• Schwann cells, myelin sheath

Question 10

Which of the following is not true about peripheral nervous system neurons?

Answer 10

• The synaptic terminals of the neuron physically connect to the dendrites of the adjoining neuron.