The Nervous System

Question 1

describe the divisions of the of the nervous system

Answer 1

brain, spinal cord and peripheral nervous system

Question 2

Divisions of the nervous system

Answer 2

1. CNS
   a. brain (cerebellum, cerebrum, diencephalon, brainstem - midbrain pons medulla)
   b. spinal cord = ganglions, nerves, etc.
2. PNS
   a. 12 pairs cranial nerves - which exit the skull
   b. 31 pairs spinal nerves
   - peripheral nerves

Question 3

Functional division of NS

Answer 3

1. SNS - somatic
2. ANS - autonomic - sympathetic/parasympathetic
3. ENS - enteric

Question 4

sympathetic nervous system is

Answer 4

voluntary. connected to skeletal muscles.

Question 5

autonomic nervous system is

Answer 5

involuntary. connected to cardiac and smooth muscles, and glands.

Question 6

enteric nervous system is

Answer 6

involuntary. connected to smooth muscles, endocrine cells of GI tract.

Question 7

Basic functions of the NS

Answer 7

Stimulus (input) –> sensory division (AP from the periphery to the CNS) –> CNS processes –> Motor division (AP to periphery) –> SNS and ANS –> Response (output)

Question 8

Typical spinal nerves - state the numbers and names in order

Answer 8

Cervical 8
Thoracic 12
Lumbar 5
Sacral 5
Coccygeal 1

Question 9

Spinal nerves initially arise from the spinal cord as _____1______; the rootlets converge to from two nerve roots which are:
_______2_____ and _______3_______

Answer 9

1. rootlets
2. anterior (ventral nerve root) - motor efferent fibres
3. posterior (dorsal) nerve root - sensory afferent fibres

Question 10

Neurons main functions are:

Answer 10

Receive stimuli and transmit action potential.

Question 11

Have three basic components:

Answer 11

The cell body (soma) is the primary site of protein synthesis.

Dendrites are short, branched cytoplasmic extensions of the cell body that usually conduct electric signals toward the cell body.

An axon is a cytoplasmic extension of the cell body that transmits action potentials to other cells.

Question 12

CNS Neuroglia: 4 main cells

Answer 12

1) Astrocytes (Protoplasmic and Fibrous)
a) Provide Support (microfilaments structure)
b) Maintain BBB
c) In embryo regulates growth, migration & Interconnection of neurons
d) Maintain environment in generation of nerve impulses (controlling K+ and NT concentration)

2) Oligodendrocytes : myelin sheath formation
3) Microglia : Phagocytes of the CNS
4) Ependymal cells : monitor CSF circulation

Question 13

PNS neuroglia: 2 types of cells

Answer 13

1. Schwann cells = myelination

2. Satellite cells = structral support and exchange