Reference no: EM133307922

Assignment:

1. What is the normal sequence of events following the stimulation of a neuron?

A. Depolarization of axon membrane, rush of potassium ions into the membrane, refractory period

B. Rush of sodium ions into the axon, refractory period, depolarization of axon membrane

C. Rush of sodium ions into the axon, depolarization of axon membrane, refractory period

D. Refractory period, rush of sodium ions into the axon, depolarization of axon membrane

2. If the neuron were stimulated at Location 2, the impulse would travel toward

A. location 1, where synaptic transmission occurs

B. location 3, where no synaptic transmission occurs

C. locations 1 and 3, causing synaptic transmission at each end

D. location 1, causing synaptic transmission at 3 only

3. When the cerebellum is damaged, a physiological effect is the loss of

A. memory

B. hearing

C. emotions

D. balance

4. Multiple sclerosis is a disease in which the myelin sheaths of neurons degenerate. A person with this disease has

A. an increased rate of diffusion of acetylcholine in synapses

B. a decreased rate of diffusion of acetylcholine in synapses

C. an increased speed of nerve impulse transmission

D. a decreased speed of nerve impulse transmission

5. An optometrist who wants to dilate the pupil to study the interior of the eye would likely administer a drug to stimulate the

A. central nervous system

B. somatic nervous system

C. sympathetic nervous system

D. parasympathetic nervous system

6. A person who experienced paralysis occasionally was examined and found to have very low levels of potassium in the blood and other tissues. The paralysis likely resulted because of the inability of

A. capillaries to provide adequate blood flow

B. axon terminals to break down acetylcholine

C. neurons to repolarize during the refractory period

D. neurons to remove acetylcholine from the synapse

7. Multiple sclerosis is a disorder that causes the destruction of myelin sheaths surrounding neurons. Neurons are not "insulated" from each other. People with multiple sclerosis display many symptoms, including slurred speech, double vision, and poor muscle co-ordination. What is the direct effect of multiple sclerosis on nerve impulse transmission?

A. Dendrites cannot be stimulated by acetylcholine; therefore, impulses are not generated in neurons.

B. Axons cannot secrete acetylcholine; therefore, impulses are not able to travel across synapses.

C. The threshold level of stimulation for neurons is greater than normal.

D. The movement of impulses along neurons is slower than normal.

8. Stimulation of an individual's sympathetic nervous system in response to imminent danger leads to all the following responses except

A. dilation of pupils of the eyes

B. constriction of the bronchioles of the lungs

C. constriction of the arterioles of the intestines

D. dilation of the arterioles of the skeletal muscles

9. A young child can easily sing favourite nursery rhymes. The part of the brain that is directly responsible for the recall of previously learned words is the

A. cerebrum

B. cerebellum

C. pituitary gland

D. medulla oblongata

10. After hitting your thumb accidentally with a hammer, you quickly withdraw your hand. You do not feel pain for a short period of time. This sequence of events may be explained by the fact that the

A. threshold of the receptor has been so greatly exceeded that the neuron does not pass the message to the brain

B. neural impulse is so large that the brain is unable to interpret the signal because it is beyond the range of tolerance

C. neural processing occurred in the spinal cord first, which caused you to quickly remove your thumb from further damage

D. sensory receptors in the thumb were damaged by the blow and are unable to initiate a stimulus to the sensory nerve

Use the following information to answer questions 8 to 10.

Numerical Response

1. What is the resting membrane potential for this neuron, expressed to two digits, and what is the maximum membrane potential during depolarization, expressed to two digits? (Record your answers as absolute values.)

Resting Maximum during

Potential Depolarization

2. Which of the following types of ion movements across an axon membrane would cause the action potential to change during the interval from 0.2 ms to 0.4 ms?

A. Sodium ions moving into the axon

B. Sodium ions moving out of the axon

C. Potassium ions moving into the axon

D. Potassium ions moving out of the axon

3. On the graph, the period from 0.5 ms to 1.0 ms represents the neuron's

A. threshold period, which is when minimum depolarization occurs

B. threshold period, which is when repolarization occurs

C. refractory period, which is when minimum depolarization occurs

D. refractory period, which is when repolarization occurs.