Physiology I w/Lab Exam Q&A | Portage Learning
1. The type of muscle tissue that is voluntary, striated, and attached to bones is:
A) Cardiac muscle
B) Smooth muscle
C) Skeletal muscle
D) Visceral muscle
Correct Answer: C) Skeletal muscle
Rationale: Skeletal muscle is under conscious control, has cross-striations visible
under the microscope, and is anchored by tendons to the skeleton for
movement. Cardiac and smooth muscle are involuntary; visceral refers to
smooth muscle in organs.
2. Which of the following is NOT one of the four functional characteristics of
muscle tissue?
A) Excitability
B) Contractility
C) Secretion
D) Extensibility
Correct Answer: C) Secretion
,Rationale: Muscle tissue is characterized by excitability (response to stimuli),
contractility (shortening), extensibility (stretching), and elasticity (recoil).
Secretion is a function of glandular epithelium, not muscle.
3. The ability of muscle tissue to return to its original shape after being
stretched is called:
A) Elasticity
B) Extensibility
C) Contractility
D) Excitability
Correct Answer: A) Elasticity
Rationale: Elasticity is the property that allows muscle to recoil after passive or
active lengthening. Extensibility is the ability to be stretched; contractility is the
ability to shorten forcefully.
4. The plasma membrane of a skeletal muscle fiber is the:
A) Sarcoplasm
B) Sarcolemma
C) Sarcoplasmic reticulum
D) Endomysium
Correct Answer: B) Sarcolemma
, Rationale: The sarcolemma is the excitable cell membrane that propagates
action potentials. Sarcoplasm is the cytoplasm; sarcoplasmic reticulum stores
calcium; endomysium is the connective tissue around each fiber.
5. The cytoplasm of a muscle fiber is called the:
A) Sarcolemma
B) Sarcoplasm
C) Myofibril
D) Neuroplasm
Correct Answer: B) Sarcoplasm
Rationale: Sarcoplasm is the intracellular fluid containing glycogen, myoglobin,
and organelles. The sarcolemma is the membrane; myofibrils are the contractile
organelles within the sarcoplasm.
6. The functional unit of contraction in a skeletal muscle fiber is the:
A) Myofibril
B) Sarcomere
C) Motor unit
D) Muscle fascicle
Correct Answer: B) Sarcomere