A&P 1 Exam 3 | Anatomy and Physiology
Practice Exam PDF
1. Which type of muscle tissue is striated, involuntary, and contains intercalated
discs?
A. Skeletal muscle
B. Smooth muscle
C. Cardiac muscle
D. Visceral muscle
Correct ,,,,answer,,,,: C
Rationale: Cardiac muscle is striated and involuntary, with intercalated discs for
electrical coupling. Skeletal is striated but voluntary. Smooth is non-striated and
involuntary.
2. The functional unit of a skeletal muscle fiber is the:
A. Sarcomere
B. Myofibril
C. Myofilament
D. Sarcolemma
Correct ,,,,answer,,,,: A
Rationale: The sarcomere is the basic contractile unit of skeletal muscle, extending
from Z-disc to Z-disc.
,3. Which protein makes up the thick filament in skeletal muscle?
A. Actin
B. Myosin
C. Troponin
D. Tropomyosin
Correct ,,,,answer,,,,: B
Rationale: Thick filaments are composed primarily of myosin. Thin filaments
contain actin, troponin, and tropomyosin.
4. During muscle contraction, the I band:
A. Widens
B. Shortens
C. Remains the same
D. Disappears completely
Correct ,,,,answer,,,,: B
Rationale: The I band shortens during contraction as thin filaments slide inward.
The A band remains constant.
5. The neuromuscular junction is the synapse between a motor neuron and a:
A. Sensory neuron
B. Muscle fiber
C. Bone
D. Tendon
,Correct ,,,,answer,,,,: B
Rationale: The neuromuscular junction is the synapse between a motor neuron and
a skeletal muscle fiber.
6. Which neurotransmitter is released at the neuromuscular junction to stimulate
skeletal muscle contraction?
A. Dopamine
B. Serotonin
C. Acetylcholine (ACh)
D. Norepinephrine
Correct ,,,,answer,,,,: C
Rationale: Acetylcholine is the neurotransmitter at the neuromuscular junction. It
binds to nicotinic receptors on the sarcolemma.
7. The enzyme that breaks down acetylcholine in the synaptic cleft is:
A. Acetylcholinesterase (AChE)
B. Monoamine oxidase
C. ATPase
D. Kinase
Correct ,,,,answer,,,,: A
Rationale: Acetylcholinesterase breaks down ACh to terminate the signal and
prevent continuous contraction.
, 8. Which of the following is required for the cross-bridge cycle to occur?
A. Sodium
B. Potassium
C. Calcium
D. Chloride
Correct ,,,,answer,,,,: C
Rationale: Calcium binds to troponin, causing tropomyosin to move and expose
myosin-binding sites on actin.
9. The calcium required for skeletal muscle contraction is primarily stored in the:
A. Sarcolemma
B. Sarcoplasmic reticulum
C. T-tubules
D. Mitochondria
Correct ,,,,answer,,,,: B
Rationale: The sarcoplasmic reticulum stores and releases calcium ions during
excitation-contraction coupling.
10. The period of time during which a muscle fiber is unable to respond to another
stimulus is called the:
A. Latent period
B. Refractory period
C. Contraction period
D. Relaxation period
Practice Exam PDF
1. Which type of muscle tissue is striated, involuntary, and contains intercalated
discs?
A. Skeletal muscle
B. Smooth muscle
C. Cardiac muscle
D. Visceral muscle
Correct ,,,,answer,,,,: C
Rationale: Cardiac muscle is striated and involuntary, with intercalated discs for
electrical coupling. Skeletal is striated but voluntary. Smooth is non-striated and
involuntary.
2. The functional unit of a skeletal muscle fiber is the:
A. Sarcomere
B. Myofibril
C. Myofilament
D. Sarcolemma
Correct ,,,,answer,,,,: A
Rationale: The sarcomere is the basic contractile unit of skeletal muscle, extending
from Z-disc to Z-disc.
,3. Which protein makes up the thick filament in skeletal muscle?
A. Actin
B. Myosin
C. Troponin
D. Tropomyosin
Correct ,,,,answer,,,,: B
Rationale: Thick filaments are composed primarily of myosin. Thin filaments
contain actin, troponin, and tropomyosin.
4. During muscle contraction, the I band:
A. Widens
B. Shortens
C. Remains the same
D. Disappears completely
Correct ,,,,answer,,,,: B
Rationale: The I band shortens during contraction as thin filaments slide inward.
The A band remains constant.
5. The neuromuscular junction is the synapse between a motor neuron and a:
A. Sensory neuron
B. Muscle fiber
C. Bone
D. Tendon
,Correct ,,,,answer,,,,: B
Rationale: The neuromuscular junction is the synapse between a motor neuron and
a skeletal muscle fiber.
6. Which neurotransmitter is released at the neuromuscular junction to stimulate
skeletal muscle contraction?
A. Dopamine
B. Serotonin
C. Acetylcholine (ACh)
D. Norepinephrine
Correct ,,,,answer,,,,: C
Rationale: Acetylcholine is the neurotransmitter at the neuromuscular junction. It
binds to nicotinic receptors on the sarcolemma.
7. The enzyme that breaks down acetylcholine in the synaptic cleft is:
A. Acetylcholinesterase (AChE)
B. Monoamine oxidase
C. ATPase
D. Kinase
Correct ,,,,answer,,,,: A
Rationale: Acetylcholinesterase breaks down ACh to terminate the signal and
prevent continuous contraction.
, 8. Which of the following is required for the cross-bridge cycle to occur?
A. Sodium
B. Potassium
C. Calcium
D. Chloride
Correct ,,,,answer,,,,: C
Rationale: Calcium binds to troponin, causing tropomyosin to move and expose
myosin-binding sites on actin.
9. The calcium required for skeletal muscle contraction is primarily stored in the:
A. Sarcolemma
B. Sarcoplasmic reticulum
C. T-tubules
D. Mitochondria
Correct ,,,,answer,,,,: B
Rationale: The sarcoplasmic reticulum stores and releases calcium ions during
excitation-contraction coupling.
10. The period of time during which a muscle fiber is unable to respond to another
stimulus is called the:
A. Latent period
B. Refractory period
C. Contraction period
D. Relaxation period
