,BIOL251/BIOL 251 Human Anatomy & Physiology I w/Lab
1. The ability of muscle tissue to return to its original length when relaxed is called:
A) Excitability
B) Contractility
C) Extensibility
D) Elasticity
Correct Answer: Elasticity
Rationale: Elasticity is the ability of muscle tissue to recoil and resume its resting length after being
stretched. Excitability is the ability to respond to stimuli, contractility is the ability to shorten and
generate force, and extensibility is the ability to be stretched without being damaged.
2. Which type of muscle tissue is under voluntary control and appears striated under a microscope?
A) Cardiac muscle
B) Smooth muscle
C) Skeletal muscle
D) Visceral muscle
Correct Answer: Skeletal muscle
Rationale: Skeletal muscle is the only type of muscle tissue under conscious (voluntary) control and
exhibits a striated (striped) appearance due to its highly organized internal structure. Cardiac muscle is
striated but involuntary, and smooth muscle is non-striated and involuntary.
3. What are the four major functional characteristics of all muscle tissue?
A) Excitability, contractility, extensibility, and elasticity
B) Conductivity, contractility, extensibility, and elasticity
C) Excitability, contractility, plasticity, and elasticity
D) Excitability, contractility, extensibility, and rigidity
,Correct Answer: Excitability, contractility, extensibility, and elasticity
Rationale: All muscle tissues share four key properties: excitability (responsiveness to stimuli),
contractility (ability to shorten and generate force), extensibility (ability to be stretched), and elasticity
(ability to recoil after stretching).
4. Which type of muscle tissue is both striated and involuntary?
A) Skeletal muscle
B) Cardiac muscle
C) Smooth muscle
D) Both A and B
Correct Answer: Cardiac muscle
Rationale: Cardiac muscle, found only in the heart, is the only type of muscle tissue that is both striated
and under involuntary control. Skeletal muscle is striated but voluntary, while smooth muscle is
involuntary but non-striated.
5. Muscles can only pull; they cannot push. This statement is:
A) True
B) False
Correct Answer: True
Rationale: Muscles are able to contract and shorten, which pulls on bones to create movement. They are
not capable of active lengthening or pushing; instead, the opposing (antagonist) muscle relaxes and
lengthens to allow the movement to occur.
6. The plasma membrane of a skeletal muscle fiber is called the:
A) Sarcoplasm
, B) Sarcolemma
C) Sarcoplasmic reticulum
D) Endomysium
Correct Answer: Sarcolemma
Rationale: The sarcolemma is the specialized plasma membrane of a muscle fiber (cell). The sarcoplasm
is the cytoplasm of the cell, the sarcoplasmic reticulum is a specialized smooth ER that stores calcium,
and the endomysium is a connective tissue layer.
7. The cytoplasm of a skeletal muscle fiber is known as the:
A) Sarcolemma
B) Sarcoplasm
C) Sarcoplasmic reticulum
D) T-tubule
Correct Answer: Sarcoplasm
Rationale: The sarcoplasm is the cytoplasm of a muscle fiber, containing the organelles and myofibrils.
The sarcolemma is the cell membrane, and the sarcoplasmic reticulum is the organelle that stores
calcium ions.
8. The functional contractile unit of a skeletal muscle fiber is the:
A) Myofibril
B) Sarcomere
C) Myofilament
D) T-tubule
Correct Answer: Sarcomere
1. The ability of muscle tissue to return to its original length when relaxed is called:
A) Excitability
B) Contractility
C) Extensibility
D) Elasticity
Correct Answer: Elasticity
Rationale: Elasticity is the ability of muscle tissue to recoil and resume its resting length after being
stretched. Excitability is the ability to respond to stimuli, contractility is the ability to shorten and
generate force, and extensibility is the ability to be stretched without being damaged.
2. Which type of muscle tissue is under voluntary control and appears striated under a microscope?
A) Cardiac muscle
B) Smooth muscle
C) Skeletal muscle
D) Visceral muscle
Correct Answer: Skeletal muscle
Rationale: Skeletal muscle is the only type of muscle tissue under conscious (voluntary) control and
exhibits a striated (striped) appearance due to its highly organized internal structure. Cardiac muscle is
striated but involuntary, and smooth muscle is non-striated and involuntary.
3. What are the four major functional characteristics of all muscle tissue?
A) Excitability, contractility, extensibility, and elasticity
B) Conductivity, contractility, extensibility, and elasticity
C) Excitability, contractility, plasticity, and elasticity
D) Excitability, contractility, extensibility, and rigidity
,Correct Answer: Excitability, contractility, extensibility, and elasticity
Rationale: All muscle tissues share four key properties: excitability (responsiveness to stimuli),
contractility (ability to shorten and generate force), extensibility (ability to be stretched), and elasticity
(ability to recoil after stretching).
4. Which type of muscle tissue is both striated and involuntary?
A) Skeletal muscle
B) Cardiac muscle
C) Smooth muscle
D) Both A and B
Correct Answer: Cardiac muscle
Rationale: Cardiac muscle, found only in the heart, is the only type of muscle tissue that is both striated
and under involuntary control. Skeletal muscle is striated but voluntary, while smooth muscle is
involuntary but non-striated.
5. Muscles can only pull; they cannot push. This statement is:
A) True
B) False
Correct Answer: True
Rationale: Muscles are able to contract and shorten, which pulls on bones to create movement. They are
not capable of active lengthening or pushing; instead, the opposing (antagonist) muscle relaxes and
lengthens to allow the movement to occur.
6. The plasma membrane of a skeletal muscle fiber is called the:
A) Sarcoplasm
, B) Sarcolemma
C) Sarcoplasmic reticulum
D) Endomysium
Correct Answer: Sarcolemma
Rationale: The sarcolemma is the specialized plasma membrane of a muscle fiber (cell). The sarcoplasm
is the cytoplasm of the cell, the sarcoplasmic reticulum is a specialized smooth ER that stores calcium,
and the endomysium is a connective tissue layer.
7. The cytoplasm of a skeletal muscle fiber is known as the:
A) Sarcolemma
B) Sarcoplasm
C) Sarcoplasmic reticulum
D) T-tubule
Correct Answer: Sarcoplasm
Rationale: The sarcoplasm is the cytoplasm of a muscle fiber, containing the organelles and myofibrils.
The sarcolemma is the cell membrane, and the sarcoplasmic reticulum is the organelle that stores
calcium ions.
8. The functional contractile unit of a skeletal muscle fiber is the:
A) Myofibril
B) Sarcomere
C) Myofilament
D) T-tubule
Correct Answer: Sarcomere
