Download I. Multiple Choice: select the best answer (four points each)

BIOS 464 Exam #2
5 November 1999
Name _____________________
I. Multiple Choice: select the best answer (four points each)
1. Troponin,
a) is a structural protein
b) has two subunits
c) is part of the myosin myofilament
d) has a calcium-binding site
2. The dorsal column tract contains:
a) ascending motor neurons
b) ascending sensory neurons
c) descending motor neurons
d) descending sensory neurons
3. Curare blocks acetylcholine receptors. This would result in:
a) increased stimulation of the muscle
b) inability of the muscle fiber to respond to nervous stimulation
c) more acetylcholinesterase production
d) increased pre-synaptic release of acetylcholine
4. ATP is required
a) to provide energy for movement of the cross-bridges
b) to detach myosin from actin after a power stroke
c) both of these
d) none of these
5. The size of various regions of the somatic sensory cortex is proportional,
a) to the size of the associated area of the body
b) to the location of the associated area of the body
c) to the number of sensory receptors in the associated area
d) to the size of the muscles in that area of the body
6. Lesions on one side of the spinal cord that damaged the anterolateral system eliminate:
a) sensations of fine touch from both sides below the lesion
b) pain sensations on the contralateral body below the lesion
c) pain sensations on the ipsilateral body below the lesion
d) sensations of itching on the ipsilateral body below the lesion
7. With a large infarction of the left ventricle, the mean QRS axis
a) shifts to the left
b) shifts to the right
c) does not change
d) is isoelectric in lead AVF
8. If the SA node is nonfunctional, which of the following will most likely occur?
a) another pacemaker will develop
b) the heart will go into asystole (stop)
c) tachycardia will develop
d) the atria will develop fibrillation
9. The period of isometric contraction is followed by:
a) ejection
b) rapid filling
c) atrial systole
d) atrial contraction
10. In looking at a patients’ EKG, lead I is generally upward. Lead AVF is generally downward.
This might indicate:
a) Right axis deviation
b) Left axis deviation
c) a normal electrical axis
d) right ventricular hypertrophy
11. The gamma motor neuron:
a) contracts extrafusal muscle fibers
b) causes the muscle spindle to shorten
c) increases activation of the -motor neuron
d) is activated by tapping the patellar tendon
II. Short answer: (eight points each)
12. Predict the consequences of the administration of an acetylcholinesterase inhibitor:
13. One could logically argue that stimulation of both the parasympathetic and sympathetic
nervous systems will increase stroke volume. Explain.
14. Explain how the ventricles fill with blood
15. Explain how a bipolar electrode works and why lead one is generally upward.
16. Describe the physiological reason for prescribing a calcium blocker .
17. Your patient (a baboon from the local zoo) receives a heart transplant. Explain how it can
adjust its cardiac output.
18. Excessive stretching of bladder may cause a contraction of the surrounding smooth
muscle. Explain the mechanism for the muscles to shorten.
18. (2pts each) – based on the following EKG from a 75 year old white female with a long
history of hypertension
(EKG printout)
a) estimate the heart rate ___________
b) describe the electrical axis
c) explain a physiological reason for the above
observations:
d) what would this EKG appear like if bundle branch block
was present