BIOL251: Human Anatomy & Physiology I w/Lab
Module 5 Exam Review – Skeletal Muscle Tissue
SECTION 1: Structure of Skeletal Muscle (Questions 1–10)
Q1: Which connective tissue layer surrounds an individual muscle fiber?
A. Epimysium
B. Perimysium
C. Endomysium [CORRECT]
D. Fascia
Correct Answer: C
Rationale: Correct because the endomysium is the delicate areolar connective tissue
that ensheathes each individual muscle fiber, distinguishing it from the epimysium
(whole muscle) and perimysium (fascicle).
Q2: A sarcomere is defined as the region between two consecutive:
A. M-lines
B. H-zones
C. Z-discs [CORRECT]
D. A-bands
Correct Answer: C
Rationale: Correct because the sarcomere represents the fundamental contractile
unit of striated muscle, extending from one Z-disc to the next Z-disc.
Q3: During muscle contraction, which band remains constant in width because its
length is determined by the thick filaments?
A. I-band
B. H-zone
C. A-band [CORRECT]
D. Z-disc
Correct Answer: C
,Rationale: Correct because the A-band corresponds to the entire length of the thick
(myosin) filaments, which do not shorten during contraction; only the thin filaments
slide past them.
Q4: Which regulatory protein binds to calcium ions during excitation-contraction
coupling to initiate cross-bridge formation?
A. Tropomyosin
B. Troponin [CORRECT]
C. Myosin
D. Actin
Correct Answer: B
Rationale: Correct because troponin is the calcium-binding regulatory protein
complex; when Ca²⁺ binds to troponin C, it triggers the conformational shift that
moves tropomyosin away from actin's myosin-binding sites.
Q5: In a resting sarcomere, which protein blocks the myosin-binding sites on actin to
prevent unwanted contraction?
A. Troponin
B. Titin
C. Tropomyosin [CORRECT]
D. Myomesin
Correct Answer: C
Rationale: Correct because tropomyosin is the threadlike regulatory protein that
spirals around actin filaments, physically obstructing the myosin-binding grooves in
the relaxed state.
Q6: The H-zone of a sarcomere contains:
A. Only thin filaments
B. Only thick filaments [CORRECT]
C. Overlapping thick and thin filaments
D. Only Z-disc proteins
Correct Answer: B
, Rationale: Correct because the H-zone is the central region of the A-band where only
thick (myosin) filaments are present; thin filaments do not extend into this zone in
the resting state.
Q7: Which cytoskeletal protein anchors thick filaments to the M-line and maintains
sarcomere structural integrity?
A. Dystrophin
B. Titin
C. Myomesin [CORRECT]
D. Nebulin
Correct Answer: C
Rationale: Correct because myomesin is the structural protein that cross-links thick
filaments and anchors them to the M-line, stabilizing the sarcomere center during
contraction.
Q8: The perimysium surrounds which structural unit of skeletal muscle?
A. Individual muscle fibers
B. Whole muscle
C. A fascicle [CORRECT]
D. A myofibril
Correct Answer: C
Rationale: Correct because the perimysium is the connective tissue sheath that wraps
each fascicle (bundle of muscle fibers), positioned between the epimysium and
endomysium.
Q9: Which of the following is NOT a component of the thin filament?
A. Actin
B. Tropomyosin
C. Troponin
D. Myosin [CORRECT]
Correct Answer: D
Module 5 Exam Review – Skeletal Muscle Tissue
SECTION 1: Structure of Skeletal Muscle (Questions 1–10)
Q1: Which connective tissue layer surrounds an individual muscle fiber?
A. Epimysium
B. Perimysium
C. Endomysium [CORRECT]
D. Fascia
Correct Answer: C
Rationale: Correct because the endomysium is the delicate areolar connective tissue
that ensheathes each individual muscle fiber, distinguishing it from the epimysium
(whole muscle) and perimysium (fascicle).
Q2: A sarcomere is defined as the region between two consecutive:
A. M-lines
B. H-zones
C. Z-discs [CORRECT]
D. A-bands
Correct Answer: C
Rationale: Correct because the sarcomere represents the fundamental contractile
unit of striated muscle, extending from one Z-disc to the next Z-disc.
Q3: During muscle contraction, which band remains constant in width because its
length is determined by the thick filaments?
A. I-band
B. H-zone
C. A-band [CORRECT]
D. Z-disc
Correct Answer: C
,Rationale: Correct because the A-band corresponds to the entire length of the thick
(myosin) filaments, which do not shorten during contraction; only the thin filaments
slide past them.
Q4: Which regulatory protein binds to calcium ions during excitation-contraction
coupling to initiate cross-bridge formation?
A. Tropomyosin
B. Troponin [CORRECT]
C. Myosin
D. Actin
Correct Answer: B
Rationale: Correct because troponin is the calcium-binding regulatory protein
complex; when Ca²⁺ binds to troponin C, it triggers the conformational shift that
moves tropomyosin away from actin's myosin-binding sites.
Q5: In a resting sarcomere, which protein blocks the myosin-binding sites on actin to
prevent unwanted contraction?
A. Troponin
B. Titin
C. Tropomyosin [CORRECT]
D. Myomesin
Correct Answer: C
Rationale: Correct because tropomyosin is the threadlike regulatory protein that
spirals around actin filaments, physically obstructing the myosin-binding grooves in
the relaxed state.
Q6: The H-zone of a sarcomere contains:
A. Only thin filaments
B. Only thick filaments [CORRECT]
C. Overlapping thick and thin filaments
D. Only Z-disc proteins
Correct Answer: B
, Rationale: Correct because the H-zone is the central region of the A-band where only
thick (myosin) filaments are present; thin filaments do not extend into this zone in
the resting state.
Q7: Which cytoskeletal protein anchors thick filaments to the M-line and maintains
sarcomere structural integrity?
A. Dystrophin
B. Titin
C. Myomesin [CORRECT]
D. Nebulin
Correct Answer: C
Rationale: Correct because myomesin is the structural protein that cross-links thick
filaments and anchors them to the M-line, stabilizing the sarcomere center during
contraction.
Q8: The perimysium surrounds which structural unit of skeletal muscle?
A. Individual muscle fibers
B. Whole muscle
C. A fascicle [CORRECT]
D. A myofibril
Correct Answer: C
Rationale: Correct because the perimysium is the connective tissue sheath that wraps
each fascicle (bundle of muscle fibers), positioned between the epimysium and
endomysium.
Q9: Which of the following is NOT a component of the thin filament?
A. Actin
B. Tropomyosin
C. Troponin
D. Myosin [CORRECT]
Correct Answer: D
