I am unsure of the answers to the following questions 1) Schwann cells are a type of glial cell found in the nervous system.

I am unsure of the answers to the following questions

1) Schwann cells are a type of glial cell found in the nervous system. In addition to the conduction of nerve impulses, the outermost layer called neurilemma aids in nerve development and regeneration. 

Which of the following explains why the neurons in the brain cannot repair damage like the neurons in your hands or feet can?

Select one:

a. Neurons in the central nervous system are surrounded by white matter.

b. Neurons in the central nervous system lack neurilemma of Schwann cells.

c. Neurons in the peripheral nervous system are surrounded by grey matter.

d. Axons of the peripheral nervous system lack neurilemma of Schwann cells.

2) Why is the speed of nerve transmission faster along axons than across synapses?

Select one:

a. The movement of neurotransmitter is faster along axons.

b. The movement of neurotransmitter is slower across synapses.

c. The movement of neurotransmitter is slower along axons.

d. The movement of neurotransmitter is faster across synapses.

3) What factors increase the speed of nerve impulses in the nervous system?

Select one:

a. The presence of myelin sheaths and thickness of axons

b. The length and thickness of axons

c. The presence of white and grey matters

d. The presence of myelin sheaths and length of axons

4) Damage to neurons from brain trauma may prevent neurons from receiving signals from other neurons.

Which of the following structures of a neuron would first be affected by the damage? 

Select one:

a. Dendrites

b. Axon

c. Cell Body

d. Axon Terminal

5) Emergency room doctors often shine a light into the eyes of patients with potential trauma to the brain to test their pupillary reflex. This is an important method in determining possible damage in the following areas of the nervous system, EXCEPT the

Select one:

a. interneuron

b. optic nerve and circular muscle of iris

c. sensory neuron and motor neuron

d. occipital lobe

6) Which of the following is NOT a reason why a reflex arc is faster than a normal nerve transmission?

Select one:

a. A reflex arc stimulates the motor neurons for an immediate reaction.

b. A reflex arc does not send information to the brain to be processed.

c. A reflex arc does not involve neurotransmitters.

d. A reflex arc involves fewer neurons.

7) A voltmeter is used to measure the potential difference across a neuron's membrane. A change in potential difference will occur when an action potential is generated. 

A neurologist uses a giant squid neuron to study the propagation of an action potential. She places two voltmeters on the axon membrane to measure the potential difference: one near the dendrite and the other at the axon terminal. 

A stimulus is then applied. Often, the stimulus is applied at one end of the neuron. In this experiment, the scientist decides to stimulate the middle of the neuron. Which statement describes what the scientist would observe at the voltmeters?

Select one:

a. The voltmeter at the axon terminal will indicate a change to the potential difference.

b. The voltmeter at the dendrite will indicate a change to the potential difference.

c. Both voltmeters will indicate changes to the potential difference.

d. No changes to the potential differences will be registered at the voltmeters.

8)Taste buds are sensory receptors for taste located on the tongue. When a person eats a spicy food, receptors on the tongue pick up a stimulus. The stimulus initiates the movement of ions across the membrane. If the threshold level is reached, an action potential is generated and a signal is sent to the brain telling the brain that the food is spicy. 

The reason that some individuals have a higher tolerance to spicy food than others is due to a difference in the

Select one:

a. number of Na+/K+ ion exchange pumps

b. strength of the stimulus

c. duration of the refractory period

d. threshold level

9)Which of the following statements about the intensity of a nerve response is true?

Select one:

a. A stimulus resulting in a greater voltage shift will result in a stronger nerve impulse and increased sense of perception in the brain.

b. All stimuli, regardless of the strength, will always generate a nerve impulse.

c. A stimulus reaching the threshold level may or may not propagate a nerve impulse.

d. A small voltage shift and a large voltage shift will yield the same nerve impulse as long as the stimulus reaches the threshold level.

10)Which of the following statements correctly describes the all-or-none principle?

Select one:

a. A stimulus depolarizes all of the neurons in the body or none at all.

b. A neuron produces a complete response to every stimulus.

c. A stimulus repolarizes all of the neurons in the body or none at all.

d. A neuron produces a complete response or no response to a stimulus.

11)Which of the following choices correctly describes the sensory pathway?

Select one:

a. Sensory receptors → sensory neuron→ inter neuron → motor neuron → muscles

b. Sensory receptors → sensory neuron → parietal lobe → motor neuron → muscles

c. temporal lobe → spinal cord → motor neuron

d. Sensory neuron → brain → motor neuron

12)All of the following statements correctly describe a polarized membrane EXCEPT which statement?

Select one:

a. A resting membrane potential (RMP) of -90 mV indicates the there are more positive ions inside the axon than an RMP of -70 mV.

b. There is a difference in the charges found on the inside of the membrane to the outside.

c. An RMP of -60 mV indicates that there are more positive ions inside the axon than an RMP of -70 mV.

d. There is a separation of the charge by a membrane, resulting in its ability to do work.

13) Which of the following stimuli will result in depolarization if the threshold level of a neuron is -72 mV ?

Select one:

a. -71 mV

b. -73 mV

c. -100 mV

d. -75 mV