BIOL251 Human Anatomy & Physiology I
w/Lab 2026 | Module 6 Exam Review
|70+ Questions and Answers
SECTION 1: HISTOLOGY OF SKELETAL MUSCLE (Q1–20)
1. The plasma membrane of a muscle fiber is called the:
a) Sarcoplasm
b) Sarcolemma
c) Endomysium
d) T-tubule
2. The cytoplasm of a muscle fiber is termed:
a) Sarcoplasm
b) Sarcolemma
c) Myofibril
d) Sarcoplasmic reticulum
3. Which organelle stores calcium in resting muscle?
a) Mitochondria
b) Golgi apparatus
c) Sarcoplasmic reticulum
d) T-tubules
4. T-tubules function to:
a) Store ATP
b) Conduct action potentials deep into the fiber
c) Synthesize proteins
d) Anchor myofibrils
5. A triad consists of:
a) 1 T-tubule + 2 terminal cisternae
b) 2 T-tubules + 1 terminal cisterna
c) 1 T-tubule + 2 terminal cisternae (correct answer repeated for clarity)
d) 3 myofibrils
,6. The thick filament is composed primarily of:
a) Actin
b) Myosin
c) Troponin
d) Titin
7. The thin filament contains all EXCEPT:
a) Actin
b) Tropomyosin
c) Troponin
d) Myosin
8. Which protein acts as a molecular spring in the sarcomere?
a) Nebulin
b) Titin
c) Alpha-actinin
d) Dystrophin
9. The Z-disc is primarily made of:
a) Myosin
b) Actinin
c) Troponin
d) Collagen
10. During contraction, the H zone:
a) Widens
b) Shortens
c) Remains the same
d) Disappears completely (only in maximal contraction) – Shortens is best answer
11. The M line is found within the:
a) I band
b) H zone (center of A band)
c) Z-disc
d) Sarcoplasmic reticulum
12. Which band remains constant length during contraction?
a) I band
b) A band
, c) H zone
d) Sarcomere
13. The protein that connects thin filaments to the Z-disc is:
a) Titin
b) Alpha-actinin
c) Nebulin
d) Myomesin
14. Dystrophin deficiency causes:
a) Myasthenia gravis
b) Duchenne muscular dystrophy
c) Tetany
d) Fibromyalgia
15. Which fiber type has the largest diameter?
a) Type I
b) Type IIx (fast glycolytic)
c) Type IIa
d) Cardiac muscle
16. Which fiber type has the highest myoglobin content?
a) Type I
b) Type IIa
c) Type IIx
d) Smooth muscle
17. Slow-twitch fibers are best for:
a) Sprinting
b) Marathon running
c) Weightlifting
d) Jumping
18. Fast-glycolytic fibers obtain ATP primarily through:
a) Oxidative phosphorylation
b) Anaerobic glycolysis
c) Creatine phosphate (only first few seconds)
d) Beta-oxidation
19. Which fiber type is most fatigue-resistant?
a) Type I
w/Lab 2026 | Module 6 Exam Review
|70+ Questions and Answers
SECTION 1: HISTOLOGY OF SKELETAL MUSCLE (Q1–20)
1. The plasma membrane of a muscle fiber is called the:
a) Sarcoplasm
b) Sarcolemma
c) Endomysium
d) T-tubule
2. The cytoplasm of a muscle fiber is termed:
a) Sarcoplasm
b) Sarcolemma
c) Myofibril
d) Sarcoplasmic reticulum
3. Which organelle stores calcium in resting muscle?
a) Mitochondria
b) Golgi apparatus
c) Sarcoplasmic reticulum
d) T-tubules
4. T-tubules function to:
a) Store ATP
b) Conduct action potentials deep into the fiber
c) Synthesize proteins
d) Anchor myofibrils
5. A triad consists of:
a) 1 T-tubule + 2 terminal cisternae
b) 2 T-tubules + 1 terminal cisterna
c) 1 T-tubule + 2 terminal cisternae (correct answer repeated for clarity)
d) 3 myofibrils
,6. The thick filament is composed primarily of:
a) Actin
b) Myosin
c) Troponin
d) Titin
7. The thin filament contains all EXCEPT:
a) Actin
b) Tropomyosin
c) Troponin
d) Myosin
8. Which protein acts as a molecular spring in the sarcomere?
a) Nebulin
b) Titin
c) Alpha-actinin
d) Dystrophin
9. The Z-disc is primarily made of:
a) Myosin
b) Actinin
c) Troponin
d) Collagen
10. During contraction, the H zone:
a) Widens
b) Shortens
c) Remains the same
d) Disappears completely (only in maximal contraction) – Shortens is best answer
11. The M line is found within the:
a) I band
b) H zone (center of A band)
c) Z-disc
d) Sarcoplasmic reticulum
12. Which band remains constant length during contraction?
a) I band
b) A band
, c) H zone
d) Sarcomere
13. The protein that connects thin filaments to the Z-disc is:
a) Titin
b) Alpha-actinin
c) Nebulin
d) Myomesin
14. Dystrophin deficiency causes:
a) Myasthenia gravis
b) Duchenne muscular dystrophy
c) Tetany
d) Fibromyalgia
15. Which fiber type has the largest diameter?
a) Type I
b) Type IIx (fast glycolytic)
c) Type IIa
d) Cardiac muscle
16. Which fiber type has the highest myoglobin content?
a) Type I
b) Type IIa
c) Type IIx
d) Smooth muscle
17. Slow-twitch fibers are best for:
a) Sprinting
b) Marathon running
c) Weightlifting
d) Jumping
18. Fast-glycolytic fibers obtain ATP primarily through:
a) Oxidative phosphorylation
b) Anaerobic glycolysis
c) Creatine phosphate (only first few seconds)
d) Beta-oxidation
19. Which fiber type is most fatigue-resistant?
a) Type I
