,BIOL 251 Module 5 Exam | Human Anatomy &
Physiology I w/Lab Exam Q&A | Portage Learning
1. Which type of muscle tissue is under involuntary control and lacks striations?
A) Skeletal muscle
B) Smooth muscle
C) Cardiac muscle
D) Both B and C
Correct Answer: B) Smooth muscle
Rationale: Smooth muscle is non‑striated, spindle‑shaped, and involuntary,
found in the walls of hollow organs and blood vessels. Cardiac muscle is striated
and involuntary. Skeletal muscle is striated and voluntary.
2. The ability of muscle tissue to be stretched without being damaged is called:
A) Contractility
B) Excitability
C) Elasticity
D) Extensibility
Correct Answer: D) Extensibility
Rationale: Extensibility is the capacity to lengthen passively when a force is
applied, as when the stomach expands. Contractility is shortening; excitability is
responsiveness; elasticity is recoil.
,3. The outermost layer of dense irregular connective tissue that surrounds an
entire skeletal muscle organ is the:
A) Epimysium
B) Perimysium
C) Endomysium
D) Sarcolemma
Correct Answer: A) Epimysium
Rationale: The epimysium is the fibrous outer sheath that separates the muscle
from surrounding tissues. Perimysium surrounds fascicles; endomysium wraps
individual fibers; sarcolemma is the muscle fiber membrane.
4. A bundle of individual skeletal muscle fibers wrapped together by a layer of
connective tissue called the perimysium is known as a:
A) Myofibril
B) Sarcomere
C) Fascicle
D) Motor unit
Correct Answer: C) Fascicle
Rationale: A fascicle is a group of muscle fibers bound by perimysium. Myofibrils
are contractile organelles within fibers; sarcomeres are the contractile units
within myofibrils; a motor unit is a neuron and its fibers.
, 5. Which of the following is NOT a characteristic of cardiac muscle tissue?
A) Multinucleated cells
B) Striations
C) Involuntary control
D) Intercalated discs
Correct Answer: A) Multinucleated cells
Rationale: Cardiac muscle cells are usually uninucleated and centrally located.
They are striated, involuntary, and connected by intercalated discs that allow
rapid impulse conduction and synchronized contraction.
6. The functional contractile unit of a skeletal muscle fiber is the:
A) Myofibril
B) Motor unit
C) Sarcomere
D) T‑tubule
Correct Answer: C) Sarcomere
Rationale: The sarcomere extends from one Z disc to the next and contains the
actin and myosin filaments whose sliding produces contraction. Myofibrils are
composed of sarcomeres in series. T‑tubules transmit signals.
7. The I band of a sarcomere contains:
Physiology I w/Lab Exam Q&A | Portage Learning
1. Which type of muscle tissue is under involuntary control and lacks striations?
A) Skeletal muscle
B) Smooth muscle
C) Cardiac muscle
D) Both B and C
Correct Answer: B) Smooth muscle
Rationale: Smooth muscle is non‑striated, spindle‑shaped, and involuntary,
found in the walls of hollow organs and blood vessels. Cardiac muscle is striated
and involuntary. Skeletal muscle is striated and voluntary.
2. The ability of muscle tissue to be stretched without being damaged is called:
A) Contractility
B) Excitability
C) Elasticity
D) Extensibility
Correct Answer: D) Extensibility
Rationale: Extensibility is the capacity to lengthen passively when a force is
applied, as when the stomach expands. Contractility is shortening; excitability is
responsiveness; elasticity is recoil.
,3. The outermost layer of dense irregular connective tissue that surrounds an
entire skeletal muscle organ is the:
A) Epimysium
B) Perimysium
C) Endomysium
D) Sarcolemma
Correct Answer: A) Epimysium
Rationale: The epimysium is the fibrous outer sheath that separates the muscle
from surrounding tissues. Perimysium surrounds fascicles; endomysium wraps
individual fibers; sarcolemma is the muscle fiber membrane.
4. A bundle of individual skeletal muscle fibers wrapped together by a layer of
connective tissue called the perimysium is known as a:
A) Myofibril
B) Sarcomere
C) Fascicle
D) Motor unit
Correct Answer: C) Fascicle
Rationale: A fascicle is a group of muscle fibers bound by perimysium. Myofibrils
are contractile organelles within fibers; sarcomeres are the contractile units
within myofibrils; a motor unit is a neuron and its fibers.
, 5. Which of the following is NOT a characteristic of cardiac muscle tissue?
A) Multinucleated cells
B) Striations
C) Involuntary control
D) Intercalated discs
Correct Answer: A) Multinucleated cells
Rationale: Cardiac muscle cells are usually uninucleated and centrally located.
They are striated, involuntary, and connected by intercalated discs that allow
rapid impulse conduction and synchronized contraction.
6. The functional contractile unit of a skeletal muscle fiber is the:
A) Myofibril
B) Motor unit
C) Sarcomere
D) T‑tubule
Correct Answer: C) Sarcomere
Rationale: The sarcomere extends from one Z disc to the next and contains the
actin and myosin filaments whose sliding produces contraction. Myofibrils are
composed of sarcomeres in series. T‑tubules transmit signals.
7. The I band of a sarcomere contains:
