Human Anatomy and Physiology II

Exam 1, Version 14 - Feb. 19, 2003

Dr. Chabot

Multiple Choice (@3 points): Circle the letter of the one best answer. GOOD LUCK!

Answer only 20 out of 23! The first 20 answered will be graded.

1. In the crossed extensor reflex, if the right bicep is stimulated:

A. the right tricep will be stimulated

B. the left tricep will be stimulated

C. the left tricep will be inhibited

D. the left bicep will be stimulated

2. The nervous system exhibits all these major functions except:

A. monitoring changes

B. integrating impulses

C. storing calcium

D. effecting responses

3. An excitatory neurotransmitter secreted by motor neurons innervating skeletal muscle is:

A. cholinesterase

B. norepinephrine

C. acetylcholine

D. gamma aminobutyric acid

4. The period after an initial stimulus when a neuron is not sensitive to another stimulus is the:

A. resting period

B. repolarization

C. depolarization

D. refractory period

5. The part of a neuron that conducts impulses away from its cell body is called a (an):

A. axon

B. dendrite

C. neurolemma

D. Schwann cell

6. At rest, what percent of our oxygen intake is consumed by the brain?

A. 10%

B. 20%

C. 30%

D. 50%

7. The role of acetylcholinesterase is to:

A. act as a transmitting agent

B. amplify or enhance the effect of Ach

C. destroy ACh a brief period after its release by the axonal endings

D. stimulate the production of serotonin

8. The substance released at axonal endings to propagate a nervous impulse is called a(an):

A. ion

B. cholinesterase

C. neurotransmitter

D. biogenic amine

9. Which of these ions is actively transported through the cell membrane to establish a resting potential:

A. Na

B. Cl

C. Mg

D. Ca

10. Choose the statement that is most correct about membrane potential:

A. voltage is measured by placing two electrodes on the exterior of the axon

B. voltage is measured by placing one electrode inside the membrane and another outside the membrane

C. voltage is measured by placing one electrode on one end of the axon and another electrode on the other end

D. voltage is measured by placing one electrode on the axon and grounding the other electrode

11. The sodium/potassium pump:

A. pumps three sodium ions outside the cell for every two potassium ions inside

B. pumps two sodium ions outside the cell for every three potassium ions inside

C. pumps three sodium ions inside the cell for every two potassium ions outside

D. pumps two sodium ions inside the cell for every three potassium ions outside

12. Immediately after an action potential has peaked, which cellular gates open?

A. sodium

B. chloride

C. calcium

D. potassium

13. The spinal cord has gray matter on the:

A. outside, white matter on the inside, and a dorsal motor root

B. inside, white matter on the outside, and a ventral motor root

C. inside, white matter on the outside, and a dorsal motor root

D. outside, white matter on the inside, and a ventral motor root

14. Striking the "funny bone" is actually stimulation of the:

A. radial nerve

B. sciatic nerve

C. ulnar nerve

D. median nerve

15. ________ are involved in the transport of neurotransmitters along the axon.

A. kinesins or dyneins

B. microtubules

C. vessicles

D. all of the above

16. If the same neurotransmitter is dumped onto two different neurons and yet cause two different effects, the difference between the two neurons can be attributed to differences in:

A. the membranes

B. the receptors

C. the voltage mediated Na channels

17. TEA, a neurotoxin, blocks:

A. the active transport pump which maintains ion gradients

B. K+ channels

C. Na+ channels

D. Cl- channels

18. Sodium and potassium ion channel selectivity appears to be based on:

A. different charges on the ions

B. channel recognition factor

C. the fact that one is a salt

D. size differences between ions

19. Action potentials travel faster in myelinated axons because:

A. myelin acts as a super conductor and speeds up the conduction

B. the action potentials jumps (travels very fast) between the nodes of Ranvier

C. the myelin greatly increases the resistance of the axonal cytoplasm

D. myelin acts as an enzyme which speeds up (catalyzes) the reaction

20. Sensory information from receptors in the body travels up the spinal cord to the brain along the:

A. spinocerebellar tract

B. rubrospinal tract

C. corticospinal tract

D. none of the above

21. Neurotransmitters can cause EPSPs and which of the following on post-synaptic cells?

A. second messengers to be produced

B. A gene to be turned off

C. an enzyme to be destroyed

D. all of the above

22. During development, at approximately day 20, the nervous system forms the

A. neural plate

B. neuroplasm

C. neural tube

D. the brain

23. The most rapid nerve impulses are conducted on fibers that are

A. thick and myelinated

B. thick and unmyelinated

C. thin and myelinated

D. thin and unmyelinated

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Essay/Short Answer (@ 10 pts). Answer only 4 of the following 5. The first 4 answered will be graded.

1) Draw and label a diagram showing a cross section through the spinal cord. Be as detailed as you can.

2) Describe how an action potential occurs in an axon. You may use diagrams to support your written text.

3) Draw a graph of membrane potential and ionic current over times after a neuron has been stimulated past threshold. Briefly describe what is happening to the membrane over time.

4) List four types of glial cells and briefly describe their function.

5) Briefly describe any of the scientific articles that we discussed in class.