) Anatomy and Physiology II with
Lab | Complete Guide with Questions and
Verified Answers | 100% Correct -
Chamberlain
Muscular System (Questions 1–20)
Question 1
True or False: Smooth muscles are characterized by striations.
Answer: False
Rationale: Smooth muscles lack striations, unlike skeletal and cardiac muscles, which have a
striated appearance due to organized sarcomeres.
Question 2
Which connective tissue surrounds 10–100 muscle fibers, separating them into bundles known as
fascicles?
A. Endomysium
B. Supramysium
C. Perimysium
D. Epimysium
Answer: C. Perimysium
Rationale: Perimysium surrounds fascicles (bundles of muscle fibers). Endomysium surrounds
individual fibers, epimysium surrounds the entire muscle, and supramysium is not a standard
term.
Question 3
The organization of muscle tissue from smallest to largest is:
A. Fiber, filament, myofibril, fascicle, skeletal muscle
B. Filament, myofibril, fiber, fascicle, skeletal muscle
C. Myofibril, filament, fiber, fascicle, skeletal muscle
D. Fascicle, fiber, filament, myofibril, skeletal muscle
Answer: B. Filament, myofibril, fiber, fascicle, skeletal muscle
Rationale: Muscle tissue organization starts with actin and myosin filaments, forming
, myofibrils, which are bundled into muscle fibers (cells), then fascicles, and finally the skeletal
muscle.
Question 4
What is the most common neurotransmitter used at the neuromuscular junction to excite the
sarcolemma?
A. Dopamine
B. Acetylcholine
C. Serotonin
D. GABA
Answer: B. Acetylcholine
Rationale: Acetylcholine is released at the neuromuscular junction to stimulate skeletal muscle
contraction by depolarizing the sarcolemma.
Question 5
Which chemical reaction provides a skeletal muscle with about 15 seconds of energy?
A. Beta oxidation
B. Synthesis of creatine phosphate
C. Anaerobic glycolysis
D. Aerobic respiration
E. Krebs cycle
Answer: B. Synthesis of creatine phosphate
Rationale: Creatine phosphate provides rapid ATP production for short bursts (10–15 seconds)
of muscle activity. Other processes provide energy over longer periods.
Question 6
A skeletal muscle contraction where the resistance is overcome and the muscle shortens is called:
A. Concentric isotonic contraction
B. Eccentric isotonic contraction
C. Isometric contraction
D. Concentric isometric contraction
E. Eccentric isometric contraction
Answer: A. Concentric isotonic contraction
Rationale: Concentric isotonic contraction involves muscle shortening to overcome resistance.
Eccentric involves lengthening, and isometric involves no length change.
Question 7
When performing a sprint, which type of muscle fibers are primarily used?
A. Slow oxidative (Type I)
B. Fast oxidative (Type IIa)
C. Fast glycolytic (Type IIx)
D. Intermediate fibers