Nervous System Basics

Question 1

What structures compose the CNS?

Answer 1

The brain and spinal cord

Question 2

What structures compose the PNS?

Answer 2

The PNS consists of nerve fibers and cell bodies outside the CNS that conduct nerve impulses to and from the CNS

Question 3

Describe the somatic nervous system (SNS)

Answer 3

The somatic nervous system is the voluntary nervous system. It carries sensation like pain from the skin and position sense from the joints. It also supplies skeletal muscle

Question 4

Describe the autonomic nervous system

Answer 4

The autonomic nervous system is automatic, involuntary, or visceral. It supplies the smooth muscle, glands, and viscera in the body cavities

Question 5

If a patient cannot move their leg when they think about moving their leg, what nervous system is affected?

Answer 5

Somatic nervous system in the peripheral system

Question 6

If a patient cannot vasodilate their blood vessels, what nervous system may be malfunctioning?

Answer 6

The autonomic system

Question 7

What is a neuron?

Answer 7

Neurons are the basic functional and structural unit of the nervous system. They are designed for rapid communication.

Question 8

What is myelin made up of and what does it do?

Answer 8

Layers of lipids and proteins. It forms a sheath around some neurons and increases the speed of impulse conduction.

Question 9

What are neuroglia?

Answer 9

Neuroglia are like the caregivers of neurons. They support, nourish, and insulate the neurons. They are five times as abundant as neurons and are nonneuronal, nonexcitable cells. Neuroglia are like the scaffolding of nervous tissue.

Question 10

What are the principle roles of the CNS?

Answer 10

The CNS integrates information and performs higher mental functions like thinking and learning. It integrates incoming information and coordinates the incoming and outgoing neural signals.

Question 11

What is a collection of nerve cell bodies in the CNS called?

Answer 11

A nucleus

Question 12

What is a tract?

Answer 12

A bundle of nerve fibers (axons) connecting neighboring or distant nuclei of the CNS. Interconnecting fiber tracts make up the white matter.

Question 13

What makes up the gray matter of the CNS?

Answer 13

Nerve cell bodies. They lie deeper within.

Question 14

What are the three meninges of the CNS?

Answer 14

Pia mater, arachnoid mater, and dura mater

Question 15

What surrounds and protects the CNS?

Answer 15

The meninges and cerebrospinal fluid

Question 16

What do peripheral nerves consist of?

Answer 16

Bundles of nerve fibers, their connective tissue covering, and blood vessels (the vasa nervorum)

Question 17

What cells does the PNS consist of?

Answer 17

Nerve cell bodies and nerve fibers

Question 18

What is a neurolemma?

Answer 18

The cell membranes of Schwann cells that immediately surround the axon, separating it from other axons

Question 19

What does a nerve fiber consist of?

Answer 19

An axon, its neurolemma, and its endoneurium (a connective sheath)

Question 20

What are the four regions of the spinal cord?

Answer 20

Cervical, thoracic, lumbar, and sacral

It extends from the foramen magnum to spinal level L1-L2

Question 21

How much of the nervous system does the spinal cord constitute?

Answer 21

Only about 2% of the whole nervous system.

Question 22

Where do nerve roots emerge?

Answer 22

Nerve roots emerge bilaterally through the intervertebral foramen.
Each spinal nerve segment has a pair of dorsal roots and a pair of ventral roots.
These nerve roots from 31 pairs of spinal nerves.

Question 23

How many dermatomes does each pair of spinal nerves monitor?

Answer 23

One

Question 24

How many pairs of cranial nerves are there?

Answer 24

12

Question 25

How many cervical nerves?

Answer 25

8

Question 26

How many thoracic nerves do you have?

Answer 26

12

Question 27

How many lumbar nerves do you have?

Answer 27

5

Question 28

How many sacral nerves do you have?

Answer 28

5

Question 29

How many coccygeal nerves do you have?

Answer 29

1

Question 30

What are the two general function of the PNS?

Answer 30

Sensory: gathers info about changes in the body and outside the body such as temp, touch, O2 levels etc. Then sends info to the CNS for processing
Motor: sends signals from the CNS to muscles or glands to elicit a response

Question 31

What are the two subdivisions of the autonomic nervous system and what do they do?

Answer 31

Parasympathetic:
“Rest and digest”. Decreases heart rate, bronchiole dilation, blood glucose, blood to skeletal muscle. Increases digestion, pupil size, urinary output.
Sympathetic:
“Fight or flight”. Decreases digestion, pupil size urinary output. Increases heart rate, bronchiole dilation, blood glucose, blood to skeletal muscle.

Question 32

What are the four large plexuses of the body?

Answer 32

Cervical plexus
Brachial plexus
Lumbar plexus
Sacral plexus