BIOD 151 Module 5: Exam Portage Learning Questions and Answers
2026 Practice Set
Module 5: The Muscular System Practice Set
1. Which type of muscle tissue is multinucleated and under voluntary control?
• A. Smooth muscle
• B. Cardiac muscle
• C. Skeletal muscle ✅
• D. Visceral muscle
Rationale: Skeletal muscle is the only type we can consciously control, and its long
fibers contain multiple nuclei.
2. The connective tissue sheath that surrounds an entire muscle is the:
• A. Endomysium
• B. Perimysium
• C. Epimysium ✅
• D. Sarcolemma
Rationale: Epimysium covers the whole muscle; perimysium covers fascicles;
endomysium covers individual fibers.
3. What is the functional unit of a skeletal muscle fiber?
• A. Sarcolemma
• B. Sarcomere ✅
• C. Myofibril
• D. T-tubule
Rationale: The sarcomere is the distance between two Z-discs where contraction
actually occurs.
4. In the "Sliding Filament Theory," which filament actually slides toward the M-
line?
, • A. Myosin (Thick)
• B. Actin (Thin) ✅
• C. Titin
• D. Tropomyosin
Rationale: Myosin heads pull the actin filaments toward the center of the sarcomere.
5. Which ion is released from the Sarcoplasmic Reticulum to trigger contraction?
• A. Sodium (Na+)
• B. Potassium (K+)
• C. Calcium (Ca2+) ✅
• D. Magnesium (Mg2+)
Rationale: Calcium binds to troponin, which then moves tropomyosin out of the way.
6. The "Orbicularis Oris" muscle is responsible for:
• A. Closing the eye
• B. Closing/puckering the lips ✅
• C. Raising the eyebrows
• D. Smiling
Rationale: "Oris" refers to the mouth; it is often called the "kissing muscle."
7. Which muscle is the primary "prime mover" for arm abduction?
• A. Pectoralis major
• B. Latissimus dorsi
• C. Deltoid ✅
• D. Biceps brachii
Rationale: The deltoid is the large triangular muscle of the shoulder that lifts the arm
away from the body.
8. A muscle that opposes or reverses a particular movement is called a(n):
• A. Agonist
, • B. Synergist
• C. Antagonist ✅
• D. Fixator
Rationale: For example, the triceps is the antagonist to the biceps during elbow flexion.
9. The neurotransmitter released at the Neuromuscular Junction (NMJ) is:
• A. Dopamine
• B. Norepinephrine
• C. Acetylcholine (ACh) ✅
• D. Serotonin
Rationale: ACh crosses the synaptic cleft to bind to receptors on the motor end plate.
10. Which muscle of the quadriceps group also acts to flex the hip?
• A. Vastus lateralis
• B. Vastus medialis
• C. Rectus femoris ✅
• D. Vastus intermedius
Rationale: Because it crosses both the hip and knee joints, the rectus femoris has dual
actions.
11. The "Z-discs" form the boundaries of a:
• A. Myofilament
• B. Sarcomere ✅
• C. Fascicle
• D. H-zone
Rationale: A sarcomere is defined as the segment between two successive Z-lines.
12. Which muscle allows you to "shrug" your shoulders?
• A. Rhomboids
• B. Trapezius ✅
2026 Practice Set
Module 5: The Muscular System Practice Set
1. Which type of muscle tissue is multinucleated and under voluntary control?
• A. Smooth muscle
• B. Cardiac muscle
• C. Skeletal muscle ✅
• D. Visceral muscle
Rationale: Skeletal muscle is the only type we can consciously control, and its long
fibers contain multiple nuclei.
2. The connective tissue sheath that surrounds an entire muscle is the:
• A. Endomysium
• B. Perimysium
• C. Epimysium ✅
• D. Sarcolemma
Rationale: Epimysium covers the whole muscle; perimysium covers fascicles;
endomysium covers individual fibers.
3. What is the functional unit of a skeletal muscle fiber?
• A. Sarcolemma
• B. Sarcomere ✅
• C. Myofibril
• D. T-tubule
Rationale: The sarcomere is the distance between two Z-discs where contraction
actually occurs.
4. In the "Sliding Filament Theory," which filament actually slides toward the M-
line?
, • A. Myosin (Thick)
• B. Actin (Thin) ✅
• C. Titin
• D. Tropomyosin
Rationale: Myosin heads pull the actin filaments toward the center of the sarcomere.
5. Which ion is released from the Sarcoplasmic Reticulum to trigger contraction?
• A. Sodium (Na+)
• B. Potassium (K+)
• C. Calcium (Ca2+) ✅
• D. Magnesium (Mg2+)
Rationale: Calcium binds to troponin, which then moves tropomyosin out of the way.
6. The "Orbicularis Oris" muscle is responsible for:
• A. Closing the eye
• B. Closing/puckering the lips ✅
• C. Raising the eyebrows
• D. Smiling
Rationale: "Oris" refers to the mouth; it is often called the "kissing muscle."
7. Which muscle is the primary "prime mover" for arm abduction?
• A. Pectoralis major
• B. Latissimus dorsi
• C. Deltoid ✅
• D. Biceps brachii
Rationale: The deltoid is the large triangular muscle of the shoulder that lifts the arm
away from the body.
8. A muscle that opposes or reverses a particular movement is called a(n):
• A. Agonist
, • B. Synergist
• C. Antagonist ✅
• D. Fixator
Rationale: For example, the triceps is the antagonist to the biceps during elbow flexion.
9. The neurotransmitter released at the Neuromuscular Junction (NMJ) is:
• A. Dopamine
• B. Norepinephrine
• C. Acetylcholine (ACh) ✅
• D. Serotonin
Rationale: ACh crosses the synaptic cleft to bind to receptors on the motor end plate.
10. Which muscle of the quadriceps group also acts to flex the hip?
• A. Vastus lateralis
• B. Vastus medialis
• C. Rectus femoris ✅
• D. Vastus intermedius
Rationale: Because it crosses both the hip and knee joints, the rectus femoris has dual
actions.
11. The "Z-discs" form the boundaries of a:
• A. Myofilament
• B. Sarcomere ✅
• C. Fascicle
• D. H-zone
Rationale: A sarcomere is defined as the segment between two successive Z-lines.
12. Which muscle allows you to "shrug" your shoulders?
• A. Rhomboids
• B. Trapezius ✅
