ch 12 (nervous tissue)

Question 1

what does the central nervous system (CNS) consist of?

Answer 1

the brain and spinal cord.
- the spinal cord is connected to the brain through the foramen magnum of the occipital bone

Question 2

what does the peripheral nervous system (PNS) consist of?

Answer 2

it consists of all nervous tissue outside the CNS: some components include
- nerves
- ganglia
- enteric plexuses
- sensory receptors

Question 3

nerve

Answer 3

a bundle of hundreds to thousands of axons, plus CT and blood vessels (outside the brain & spinal cord).

Question 4

ganglia

Answer 4

(= swelling or knot; singular is ganglion)
they are small masses of nervous tissue, consisting primarily of neuron cell bodies.
- (they are located outside the brain and spinal cord).

Question 5

how many cranial nerves emerge from the brain?

Answer 5

twelve pairs!

Question 6

how many pairs of spinal nerves emerge from the spinal cord?

Answer 6

thirty-one pairs!

Question 7

sensory receptor

Answer 7

refers to a structure of the nervous system that monitors changes in external and internal environments.
- examples: touch receptors; olfactory receptors; etc.

Question 8

what are the 3 subdivisions of the peripheral nervous system - PNS?

Answer 8

1.) somatic nervous system (SNS)
2.) autonomic nervous system (ANS)
3.) enteric nervous system (ENS)

Question 9

what does the somatic nervous system (SNS) consist of?

Answer 9

1.) sensory neurons that convey info to the CNS from somatic receptors in the head, body wall, limbs, and special senses.
2.) and motor neurons that conduct impulses from the CNS to skeletal muscles only.