Nerve Cell A&P Pt.2

Question 1

What are the 3 parts of the PNS?

Answer 1

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

Question 2

What does the sensory portion of the PNS transmit messages to?

Answer 2

The central nervous system (CNS).

Question 3

What does the CNS communicate actions to?

Answer 3

PNS motor neurons.

Question 4

What do somatic motor neuron innervate?

Answer 4

Skeletal muscle.

Question 5

What do autonomic motor neuron innervate?

Answer 5

Smooth muscle, cardiac muscle, glands.

Question 6

What do enteric motor neuron innervate?

Answer 6

Smooth muscle, glands, and endocrine cells of the GIT.

Question 7

What is the purpose of the CNS?

Answer 7

To process sensory information.
*Source of thoughts, emotions, and memories.

Question 8

What are the 4 anatomical portions of the PNS?

Answer 8

1. Cranial nerves and branches.
2. Spinal nerves and branches.
3. Ganglia.
4. Sensory receptors.

Question 9

How many cranial nerves do we have?

Answer 9

13.

Question 10

How many spinal nerves do we have?

Answer 10

21.

Question 11

What is the other name for sensory neurons?

Answer 11

Afferent neurons.

Question 12

What is the other name for motor neurons?

Answer 12

Efferent neurons.

Question 13

What do sensory/afferent neurons convey?

Answer 13

Information from somatic receptors in the head, body wall, limbs, and receptors for vision, hearing, taste, and smell to CNS.

Question 14

What is the function of motor neurons?

Answer 14

To conduct impulses from the CNS to skeletal muscles.
*Voluntary.

Question 15

What is the function of the autonomic sensory neurons?

Answer 15

Convey info from ANS sensory receptors to the CNS.

Question 16

What is the function of the autonomic motor neurons?

Answer 16

Conduct nerve impulses from CNS to smooth, cardiac muscle, and glands.
*Involuntary.

Question 17

What is the enteric nervous system nicknamed?

Answer 17

The brain of the gut.

Question 18

How many neurons are in the enteric plexus?

Answer 18

Millions.

Question 19

How far does the ENS extend through the GIT?

Answer 19

Most of its length.

Question 20

What are the functions of sensory neurons in the ENS?

Answer 20

1. Monitoring chemical changes.
2. Monitoring stretching of walls in GIT.

Question 21

What are the functions of motor neurons in the ENS?

Answer 21

1. Governs smooth muscle contractions.
2. Governs GIT secretions.
3. Governs endocrine cell activity.

Question 22

What are the 2 branches of the ANS?

Answer 22

1. Sympathetic (Fight or Flight).
2. Parasympathetic (Rest & Digest).

Question 23

What are the 4 features nerves can be classified on?

Answer 23

1. Size and shape.
2. Dendritic branching variations.
3. Axon length.
4. Function.

Question 24

What are the 3 functions a neuron could have?

Answer 24

1. Sensory.
2. Interneuron.
3. Motor.

Question 25

How are neurons typically classified?

Answer 25

According to the number of processes extending from their cell body.

Question 26

What are the 3 classifications of neurons?

Answer 26

1. Bipolar. 2. Multipolar. 3. Unipolar.

Question 27

What is a bipolar neuron?

Answer 27

A neuron that has 1 axon and 1 dendrite with the cell body in the middle of the two.

Question 28

What is a multipolar neuron?

Answer 28

A neuron with one axon and several dendrites coming out of the neuron cell body. *The classic neuron.

Question 29

What is a unipolar neuron?

Answer 29

A sensory neuron that begins as bipolar and develops a fused axon and dendrite that splits into 2 branches. The periphery extending branch develops dendrites, and the CNS extending branch develops synaptic knobs.

Question 30

Where is the trigger zone on a unipolar axon?

Answer 30

At the junction of the dendrites and axon.

Question 31

Where are the cell bodes of unipolar neurons located?

Answer 31

Ganglia of the cranial and spinal nerves.

Question 32

Where are bipolar neurons found?

Answer 32

The retina of the eye.

Question 33

Where are multipolar neurons found?

Answer 33

The brain and spinal cord.

Question 34

What are neuroglia?

Answer 34

Nervous system support cells.

Question 35

What do neuroglia do during injury or disease?

Answer 35

Multiply to fill the space formerly occupied by neurons.

Question 36

How many types of neuroglia are found in the CNS?

Answer 36

4.

Question 37

How many types of neuroglia are found in the PNS?

Answer 37

2.

Question 38

What are the 4 neuroglia found in the CNS?

Answer 38

1. Astrocytes. 2. Ependymal cells. 3. Microglia. 4. Oligodendrocytes.

Question 39

What CNS neuroglia is the largest and most numerous?

Answer 39

Astrocytes.

Question 40

What are the functions of astrocytes?

Answer 40

1. Support neurons. 2. Help create the BBB. 3. Regulates the growth, migration, and interconnection among neurons in the brain of an embryo. 4. Helps maintain appropriate chemical environment for nerve impulse generation. 5. Learning and memory.

Question 41

What is the function of oligodendrocytes?

Answer 41

Forming and maintaining the myelin sheath around CNS axons.

Question 42

What is the function of microglia?

Answer 42

Phagocytosis of old or foreign material.

Question 43

What areas of the body do the ependymal cells line?

Answer 43

1. Ventricles of the brain. 2. Central canal of the spinal cord.

Question 44

What is the function of ependymal cells?

Answer 44

Produce, monitor, and assist in CSF circulation.

Question 45

What are the 2 neuroglia found in the PNS?

Answer 45

1. Satellite cells. 2. Schwann cells.

Question 46

What are the functions of satellite cells?

Answer 46

1. Regulates the exchange of material between neuronal cell bodies and interstitial fluid. 2. Structural support. 3. Surround the cell bodies of neurons of PNS ganglia.

Question 47

What is the function of Schwann cells?

Answer 47

To myelinate the PNS axons.

Question 48

What are graded potential?

Answer 48

The potential as it builds up to the threshold. The localized membrane potential changes that, when enough occur in a small area in a short period of time, results in threshold being reached.

Question 49

What are upper motor neurons?

Answer 49

Somatic motor neurons that originate in the cerebral cortex and communicate motor messages to lower motor neurons.

Question 50

What are lower motor neurons?

Answer 50

Somatic motor neurons originating in the spinal cord that directly innervate skeletal muscle and allow for movement.