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Newest BIOL 251 Anatomy & Physiology I – Exam 3
Review: Chapters 9 & 10 (Muscle Tissue & Muscular
System) – 180 Questions with Answers & Rationales –
2026–2027 Edition
Section 1: Muscle Tissue Basics & Characteristics (Questions 1–15)
1. Which of the following is NOT a basic characteristic of muscle tissue?
A) Excitability
B) Contractility
C) Extensibility
D) Flexibility
☑ Corect Answer: D) Flexibility
Rationale: Muscle tissue has four key characteristics: excitability (ability to
respond to stimuli), contractility (ability to shorten forcibly), extensibility (ability
to be stretched), and elasticity (ability to recoil to resting length). Flexibility, while
beneficial, is not a defining physiological property of muscle tissue.
2. Approximately what fraction of total body mass is composed of muscle
tissue?
A) One-quarter (25%)
B) Nearly one-half (40–50%)
C) Two-thirds (66%)
D) One-tenth (10%)
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☑ Corect Answer: B) Nearly one-half (40–50%)
Rationale: Muscle tissue accounts for nearly half of the body’s total mass, making
it the most abundant tissue in the human body.
3. Which type of muscle tissue is striated and under voluntary control?
A) Cardiac
B) Smooth
C) Skeletal
D) Both A and C
☑ Corect Answer: C) Skeletal
Rationale: Skeletal muscle fibers contain visible striations and are consciously
controlled (voluntary). Cardiac muscle is striated but involuntary; smooth muscle
is non-striated and involuntary.
4. The plasma membrane of a muscle fiber is specifically called the:
A) Sarcolemma
B) Sarcoplasm
C) Sarcoplasmic reticulum
D) Myolemma
☑ Corect Answer: A) Sarcolemma
Rationale: The sarcolemma is the specialized plasma membrane that surrounds
each muscle fiber, analogous to the plasma membrane in other cells.
5. Which structure stores calcium ions within a muscle fiber?
A) T-tubules
B) Sarcolemma
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C) Sarcoplasmic reticulum
D) Myofibrils
☑ Corect Answer: C) Sarcoplasmic reticulum
Rationale: The sarcoplasmic reticulum (SR) is a specialized smooth ER that stores
and releases calcium ions (Ca²⁺) to initiate muscle contraction.
6. A single skeletal muscle fiber is composed of many __________.
A) Myofibrils
B) Sarcomeres
C) Motor units
D) Nuclei
☑ Corect Answer: A) Myofibrils
Rationale: Each muscle fiber contains hundreds to thousands of myofibrils, which
are the rod-like contractile organelles within the fiber.
7. Which connective tissue sheath surrounds an entire skeletal muscle?
A) Endomysium
B) Perimysium
C) Epimysium
D) Fascia
☑ Corect Answer: C) Epimysium
Rationale: The epimysium is a dense irregular connective tissue layer that wraps
around the whole muscle, blending with the deep fascia that separates muscles
from each other.
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8. The perimysium surrounds __________.
A) Individual muscle fibers
B) Fascicles (bundles of fibers)
C) The entire muscle
D) Myofibrils
☑ Corect Answer: B) Fascicles (bundles of fibers)
Rationale: The perimysium divides the muscle into compartments, each
containing a bundle (fascicle) of muscle fibers.
9. The endomysium is composed of __________ connective tissue and
surrounds __________.
A) Dense irregular; the whole muscle
B) Areolar; individual muscle fibers
C) Dense regular; fascicles
D) Elastic; tendons
☑ Corect Answer: B) Areolar; individual muscle fibers
Rationale: The endomysium is a delicate layer of areolar connective tissue that
covers each single muscle fiber, containing capillaries and nerve endings.
10. Which characteristic means a muscle can be stretched beyond its resting
length?
A) Excitability
B) Contractility
C) Extensibility
D) Elasticity
Newest BIOL 251 Anatomy & Physiology I – Exam 3
Review: Chapters 9 & 10 (Muscle Tissue & Muscular
System) – 180 Questions with Answers & Rationales –
2026–2027 Edition
Section 1: Muscle Tissue Basics & Characteristics (Questions 1–15)
1. Which of the following is NOT a basic characteristic of muscle tissue?
A) Excitability
B) Contractility
C) Extensibility
D) Flexibility
☑ Corect Answer: D) Flexibility
Rationale: Muscle tissue has four key characteristics: excitability (ability to
respond to stimuli), contractility (ability to shorten forcibly), extensibility (ability
to be stretched), and elasticity (ability to recoil to resting length). Flexibility, while
beneficial, is not a defining physiological property of muscle tissue.
2. Approximately what fraction of total body mass is composed of muscle
tissue?
A) One-quarter (25%)
B) Nearly one-half (40–50%)
C) Two-thirds (66%)
D) One-tenth (10%)
, 2
☑ Corect Answer: B) Nearly one-half (40–50%)
Rationale: Muscle tissue accounts for nearly half of the body’s total mass, making
it the most abundant tissue in the human body.
3. Which type of muscle tissue is striated and under voluntary control?
A) Cardiac
B) Smooth
C) Skeletal
D) Both A and C
☑ Corect Answer: C) Skeletal
Rationale: Skeletal muscle fibers contain visible striations and are consciously
controlled (voluntary). Cardiac muscle is striated but involuntary; smooth muscle
is non-striated and involuntary.
4. The plasma membrane of a muscle fiber is specifically called the:
A) Sarcolemma
B) Sarcoplasm
C) Sarcoplasmic reticulum
D) Myolemma
☑ Corect Answer: A) Sarcolemma
Rationale: The sarcolemma is the specialized plasma membrane that surrounds
each muscle fiber, analogous to the plasma membrane in other cells.
5. Which structure stores calcium ions within a muscle fiber?
A) T-tubules
B) Sarcolemma
, 3
C) Sarcoplasmic reticulum
D) Myofibrils
☑ Corect Answer: C) Sarcoplasmic reticulum
Rationale: The sarcoplasmic reticulum (SR) is a specialized smooth ER that stores
and releases calcium ions (Ca²⁺) to initiate muscle contraction.
6. A single skeletal muscle fiber is composed of many __________.
A) Myofibrils
B) Sarcomeres
C) Motor units
D) Nuclei
☑ Corect Answer: A) Myofibrils
Rationale: Each muscle fiber contains hundreds to thousands of myofibrils, which
are the rod-like contractile organelles within the fiber.
7. Which connective tissue sheath surrounds an entire skeletal muscle?
A) Endomysium
B) Perimysium
C) Epimysium
D) Fascia
☑ Corect Answer: C) Epimysium
Rationale: The epimysium is a dense irregular connective tissue layer that wraps
around the whole muscle, blending with the deep fascia that separates muscles
from each other.
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8. The perimysium surrounds __________.
A) Individual muscle fibers
B) Fascicles (bundles of fibers)
C) The entire muscle
D) Myofibrils
☑ Corect Answer: B) Fascicles (bundles of fibers)
Rationale: The perimysium divides the muscle into compartments, each
containing a bundle (fascicle) of muscle fibers.
9. The endomysium is composed of __________ connective tissue and
surrounds __________.
A) Dense irregular; the whole muscle
B) Areolar; individual muscle fibers
C) Dense regular; fascicles
D) Elastic; tendons
☑ Corect Answer: B) Areolar; individual muscle fibers
Rationale: The endomysium is a delicate layer of areolar connective tissue that
covers each single muscle fiber, containing capillaries and nerve endings.
10. Which characteristic means a muscle can be stretched beyond its resting
length?
A) Excitability
B) Contractility
C) Extensibility
D) Elasticity
