Download Practice Test 5

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Human Anatomy and Physiology I
Practice Test 5
1.
At its resting length, skeletal muscle contains an A band in each sarcomere.
This A band contains:
a. Essentially all myosin but no actin
b. Essentially all actin but no myosin
c. Essentially all myosin and some actin
d. Essentially all actin and some myosin
e. Troponin and tropomyosin, but no actin
2.
The rate at which Ca2+ ions is pumped back into the sarcoplasmic reticulum of
the skeletal muscle during a twitch is directly related to:
a. The rate of tension development
b. The rate of ATP hydrolysis
c. a and b
d. The height of the action potential
e. The rate of relaxation
3.
When skeletal muscles shorten in response to stimulation, there is
a. A decrease in the width of the I band
b. A decrease in the width of the A band
c. A decrease in the width of the A and I band
d. An increase in the width of the H zone
e. All of the above would occur
4.
If the nerve supply to an isolated skeletal muscle attached to a weight is
severed, it will achieve a final length:
a. Greater than its original length
b. Shorter than its original length because muscle tone is lost
c. Shorter than its original length because it is less relaxed
d. Shorter than its original length because of its elastic characteristics
e. Not different from the original length
5.
Activity in which of the following organs illustrate the muscle’s ability to
produce movement?
a. Eyeballs
b. Heart
c. Intestines
d. Arteries
e. All of the above
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6.
If a second stimulus causes a muscle to contract half way through the
relaxation phase of the first response, the second myogram would:
a. Be equal to the first since calcium levels do not change
b. Be lower than the first calcium is pumped into the sarcoplasmic reticulum
c. Be greater than the first because more calcium is released from the
sarcoplasmic reticulum
d. Have no effect on the first since both twitches are independent events
e. Have not effect because Na/K pump is actively inhibited
7.
Consider the following statements about skeletal muscles and determine if
they are TRUE.
i. The major function of the T tubule is to store and release calcium
ii. Calcium binds to tropomyosin and causes troponin to expose the
active site
iii. The bonds between actin and myosin are formed when ATP
detaches from the myosin head.
a. I, II and II are true
b. II and III are true
c. II is true
d. III is true
e. None of the statements is true
8.
For the oxygen debt incurred during vigorous exercise to be repaid:
a. Accumulated lactic acid must be reconverted to pyruvic acid
b. Glycogen stores must be replenished
c. ATP and creatine phosphate reserves must be resynthesized
d. All of the above
e. None of the above
9.
All of the following are associated with isotonic contractions EXCEPT:
a. Shortening
b. Relatively constant tension
c. Concentric contractions
d. Eccentric contractions
e. No change in muscle length
10.
Which of the following is not a function of muscles?
a. Produce movement
b. Generate heat
c. Maintain posture
d. Secrete mucous
e. Stabilize joints
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11.
Which of the following muscles is voluntary?
a. Skeletal muscles
b. Cardiac muscles
c. Smooth muscles
d. a and b
e. b and c
12.
What type of muscle is found in the uterine wall?
a. Skeletal
b. Cardiac
c. Smooth
d. a and b
e. b and c
13.
Which of the following is NOT a characteristic of single-unit smooth muscle?
a. Contracts rhythmically as a single unit
b. Responds to neural stimulation with graded contractions
c. Electrically coupled to one another by gap junctions
d. Exhibits spontaneous action potentials
e. All of the above
14.
Kenyan athletes once again dominated the most recent Boston marathon. A
biopsy from the gastrocnemius muscle of these individuals would most likely
reveal ALL of the following characteristics EXCEPT
a. Red in appearance
b. Small fiber diameter
c. Few mitochondria
d. Many capillaries
e. Many mitochondria
15.
The connective tissue membrane that surrounds a bundle of muscle fascicles
is called?
a. Epimysium
b. Endomysium
c. Perimysium
d. Epineurium
e. Perineurium
16.
A sarcomere is the region of a myofibril between two successive:
a. A bands
b. H zones
c. M lines
d. Z lines
e. I bands
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17.
The T-tubule is an invagination of the:
a. Sarcomere
b. Sarcoplasm
c. Sarcoplasmic reticulum
d. Sarcolemma
e. Neuromuscular junction
18.
The role of ATP in the process of muscle contraction is:
a. Activate the myosin head
b. Initiate the detachment of the cross bridge from the active site
c. Provide energy for the active pumping of calcium
d. All of the above
e. None of the above
19.
Contractions elicited by a single brief stimulus is called:
a. Twitch
b. Wave summation
c. Multiple motor unit Summation
d. Treppe
e. Tetanus
20.
Depolarization of the muscle cell membrane is characterized by:
a. Sodium influx
b. Potassium influx
c. Calcium influx
d. Sodium efflux
e. Sodium efflux