Exam with Verified Answers.
Which of the following substances regulates muscle actions?
Potassium
Calcium
troponin
tropomyosin - Correct Answer Calcium
Which of the following substances acts at the neuromuscular junction to excite the
muscle fibers of a motor unit?
acetylcholine
ATP
creatine phosphate
serotonin - Correct Answer acetylcholine
When throwing a baseball, an athlete's arm is rapidly stretched just before throwing the
ball. Which of the following structures detects and responds to that stretch by reflexively
increasing muscle activity?
Golgi tendon organ
Muscle spindle
extrafusal muscle
pacinian corpuscle - Correct Answer Muscle spindle
From which of the following is the heart's electrical impulse normally initiated?
AV node
SA node
the brain
the sympathetic nervous system - Correct Answer SA node
Which of the following occurs during the QRS complex of a typical ECG?
,1 depolarization of the atrium
2 repolarlization of the atrium
3 repolarization of the ventricle
4 depolarization of the ventricle
1 & 3 only
2 & 4 only
1, 2, & 3 only
2, 3, & 4 only - Correct Answer 2 & 4 only
Which of the following is the definition of power?
mass x acceleration
force x distance
force x velocity
torque x time - Correct Answer force x velocity
(velocity is distance/time)
To compare performances of Olympic weightlifters of different body weights, the classic
formula divides the load lifted by the athlete's
body weight
body weight squared
lean body weight
body weight to the two-thirds power - Correct Answer body weight to the two-thirds power
During a free weight exercise, muscle force varies with which of the following?
1 perpendicular distance from the weight to the body joint
2 joint angle
3 movement acceleration
,4 movement velocity squared
1 & 2 only
1 & 4 only
1, 2, & 3 only
2, 3, & 4 only - Correct Answer 1 & 2 only
A verticle jump involves knee, hip, and shoulder movement primarily in which anatomical
plane?
sagittal
perpendicular
frontal
transverse - Correct Answer sagittal
An athlete is performing a concentric isokinetic elbow flexion and extension exercise.
Which of the following type(s) of levers occur(s) at the elbow during this exercise?
1 first class.
2 second class.
3 third class.
1 only
2 only
1 & 3 only
2 & 3 only - Correct Answer 1 & 3 only
Which of the following substances can be metabolized anaerobically?
glycerol
glucose
amino acids
free fatty acids - Correct Answer glucose
, Which of the following reactions is the primary cause of metabolic acidosis (the decrease
in intramuscular pH during high-intensity, fatiguing exercise)
ATP -> ADP + P + H+
pyruvate + NADH -> Lactate + NAD+
ADP + creatine phosphate -> ATP + Creatine
fructose-6-phosphate -> fructose-1, 6-biphosphate - Correct Answer ATP -> ADP + P +
H+
Which of the following energy systems produces ATP at the quickest rate?
phosphagen
aerobic glycolysis
fat oxidation
fast glycolysis - Correct Answer phosphagen
Approximately how many net ATP are produced via the oxidative energy system from the
metabolism of one glucose molecule?
27
34
38
41 - Correct Answer 38
Which of the following energy substrates cannot be depleted during extreme exercise
intensities or durations?
creatine phosphate
glycogen
water
ATP - Correct Answer ATP
After a bout of resistance training, acute hormonal secretions provide all of the following
information to the body EXCEPT
amount of physiological stress