Muscle Contraction: Interactive Quizzes for Nursing Students

Question 1

Which event triggers the release of calcium from the sarcoplasmic reticulum, initiating muscle contraction?

Accepted Answer

Sarcolemma depolarization

Answer

ATP binding to myosin

Answer

ATP hydrolysis by myosin

Question 2

Which ion is essential for muscle contraction to occur?

Accepted Answer

Calcium

Answer

Sodium

Answer

Potassium

Answer

Chloride

Question 3

What is the primary source of energy for muscle contraction?

Accepted Answer

ATP

Answer

Creatine phosphate

Answer

Glucose

Answer

Fatty acids

Question 4

According to the sliding filament theory, what happens during muscle contraction?

Accepted Answer

The actin and myosin filaments slide past each other

Answer

The actin filaments shorten and the myosin filaments remain stationary

Answer

The myosin filaments shorten and the actin filaments lengthen

Answer

The filaments remain stationary and the sarcomere shortens

Question 5

What is the primary function of the sarcomere?

Accepted Answer

To provide a structural framework for muscle contraction

Answer

To store calcium ions

Answer

To synthesize proteins

Answer

To transmit nerve impulses

Question 6

How do calcium ions enter the sarcoplasm to initiate muscle contraction?

Accepted Answer

Through voltage-gated calcium channels

Answer

Through ligand-gated calcium channels

Answer

Through diffusion

Answer

Through active transport

Question 7

Which of the following drugs can inhibit muscle contraction?

Accepted Answer

Botulinum toxin

Answer

Caffeine

Answer

Nitroglycerin

Answer

Morphine

Question 8

Which ion triggers muscle contraction by binding to troponin?

Accepted Answer

Calcium

Answer

Sodium

Answer

Potassium

Answer

Magnesium

Question 9

According to the sliding filament theory, which structures slide past each other during muscle contraction?

Accepted Answer

Thin filaments and thick filaments

Answer

Myosin heads and actin

Answer

Actin and tropomyosin

Answer

Troponin and myosin

Question 10

Which step is NOT involved in excitation-contraction coupling?

Accepted Answer

Calcium binds to myosin

Answer

Action potential arrives at the neuromuscular junction

Answer

Calcium is released from the sarcoplasmic reticulum

Answer

Myosin heads attach to actin filaments

Question 11

Which type of muscle is found in the walls of blood vessels?

Accepted Answer

Smooth muscle

Answer

Skeletal muscle

Answer

Cardiac muscle

Answer

Voluntary muscle

Question 12

Which ion triggers muscle contraction by binding to receptors on the sarcoplasmic reticulum?

Accepted Answer

Calcium

Answer

Sodium

Answer

Potassium

Answer

Chloride

Question 13

The sliding filament theory describes the mechanism of muscle contraction by explaining how:

Accepted Answer

Actin and myosin filaments slide past each other.

Answer

Calcium ions bind to actin and myosin, causing them to contract.

Answer

ATP is broken down, releasing energy for contraction.

Answer

Muscle fibers shorten and thicken.

Question 14

Type IIx muscle fibers are characterized by:

Accepted Answer

Fast contraction time and high force production.

Answer

Slow contraction time and low force production.

Answer

Moderate contraction time and moderate force production.

Answer

Sustained contraction time and endurance.

Question 15

The relaxed state of a muscle is referred to as its:

Accepted Answer

Resting length

Answer

Contracted length

Answer

Hypertrophy

Answer

Hypotonia

Question 16

Which type of muscle action involves shortening the muscle and bringing the insertion closer to the origin?

Accepted Answer

Concentric

Answer

Eccentric

Answer

Isometric

Answer

Isokinetic

Question 17

The primary function of the sarcoplasmic reticulum in muscle contraction is to:

Accepted Answer

Store and release calcium ions.

Answer

Pump calcium ions out of the cell.

Answer

Break down ATP to produce energy.

Answer

Synthesize contractile proteins.

Question 18

Muscle spindles contribute to muscle function by:

Accepted Answer

Providing sensory information about muscle length and stretch.

Answer

Initiating and coordinating muscle contractions.

Answer

Regulating blood flow to muscles.

Answer

Preventing muscle atrophy.

Question 19

Which ion triggers the initiation of muscle contraction by binding to receptors on the sarcoplasmic reticulum?

Accepted Answer

Calcium

Answer

Sodium

Answer

Potassium

Answer

Chloride

Question 20

What is the term for the relaxation phase of muscle contraction?

Accepted Answer

Relaxation

Answer

Excitation-contraction coupling

Answer

Propagation

Answer

Refractory period

Question 21

Which type of muscle contraction involves shortening of the muscle?

Accepted Answer

Concentric

Answer

Isometric

Answer

Isokinetic

Answer

Eccentric

Question 22

Which type of drug inhibits muscle contraction by blocking calcium channels?

Accepted Answer

Verapamil

Answer

Propranolol

Answer

Digoxin

Answer

Furosemide

Question 23

The initiation of muscle contraction strongly relies on the presence of which ions?

Accepted Answer

Calcium

Answer

Sodium

Answer

Potassium

Answer

Chloride

Question 24

According to the sliding filament theory, what occurs during muscle contraction?

Accepted Answer

Thick and thin filaments slide past each other, shortening the muscle.

Answer

Thick filaments remain stationary while thin filaments slide past them.

Answer

Thin filaments remain stationary while thick filaments slide past them.

Answer

Both thick and thin filaments shorten during contraction.

Question 25

Which molecule provides the energy necessary for muscle contraction?

Accepted Answer

ATP

Answer

ADP

Answer

Glucose

Answer

Creatine phosphate

Question 26

Muscle relaxation occurs when:

Accepted Answer

Calcium ions are actively transported back into the sarcoplasmic reticulum.

Answer

ATP binds to the myosin heads.

Answer

Acetylcholine is released from the motor neuron.

Answer

The muscle is stretched beyond its normal length.

Question 27

A muscle twitch refers to:

Accepted Answer

A single muscle contraction followed by relaxation.

Answer

A sustained muscle contraction.

Answer

A series of rapid muscle contractions.

Answer

A slow and gradual muscle contraction.

Question 28

The time interval between the initiation of an action potential and the onset of muscle contraction is known as:

Accepted Answer

Latent period

Answer

Contraction period

Answer

Relaxation period

Answer

Refractory period

Question 29

Which type of muscle contraction is characterized by a sustained contraction without relaxation?

Accepted Answer

Tetanic contraction

Answer

Isotonic contraction

Answer

Isometric contraction

Answer

Twitch contraction

Question 30

The recruitment of motor units during muscle contraction follows the principle of:

Accepted Answer

Size principle

Answer

Rate coding

Answer

Spatial summation

Answer

Temporal summation

Question 31

How does muscle fiber recruitment influence the force generated by muscles?

Accepted Answer

By determining the number of muscle fibers activated during contraction

Answer

By affecting the speed of muscle contraction

Answer

By determining the duration of muscle contraction

Question 32

What is the immediate source of energy for muscle contraction?

Accepted Answer

ATP

Answer

Creatine phosphate

Answer

Glucose

Answer

Lactate

Question 33

Which of the following best describes the sliding filament theory of muscle contraction?

Accepted Answer

Thin (actin) and thick (myosin) filaments slide past each other, causing the muscle to shorten.

Answer

Thin (actin) and thick (myosin) filaments remain stationary, and the muscle lengthens.

Answer

Thick (myosin) filaments slide past thin (actin) filaments, causing the muscle to shorten.

Question 34

What is the primary function of troponin in muscle contraction?

Accepted Answer

Binds calcium ions and initiates a conformational change of tropomyosin, exposing myosin-binding sites on actin.

Answer

Cross-bridges actin and myosin filaments.

Answer

Hydrolyzes ATP to provide energy for contraction.

Question 35

Which type of muscle contraction occurs when the muscle shortens while generating force?

Accepted Answer

Concentric

Answer

Eccentric

Answer

Isokinetic

Answer

Isometric

Question 36

What is the refractory period in muscle contraction?

Accepted Answer

The time during which a muscle cannot be stimulated to contract again after a previous contraction.

Answer

The time required for calcium ions to be released from the sarcoplasmic reticulum.

Answer

The duration of the action potential in a muscle fiber.

Question 37

What is the key difference between a twitch and a tetanus contraction?

Accepted Answer

A tetanus contraction is a sustained contraction caused by high-frequency stimulation, while a twitch is a single, brief contraction.

Answer

A twitch contraction is stronger than a tetanus contraction.

Question 38

Which of the following is a characteristic symptom of muscular dystrophy?

Accepted Answer

Progressive muscle weakness and atrophy

Answer

Fatigue and muscle pain

Answer

Tremors and rigidity

Answer

Double vision and slurred speech

Question 39

What is the primary function of muscle spindles in muscle physiology?

Accepted Answer

To sense changes in muscle length and initiate stretch reflexes.

Answer

To generate muscle action potentials.

Answer

To store calcium ions for muscle contraction.

Question 40

Which ion triggers the initiation of muscle contraction by binding to receptors on the sarcoplasmic reticulum?

Accepted Answer

Calcium

Answer

Sodium

Answer

Potassium

Answer

Chloride

Question 41

Which molecule provides the energy for muscle contraction?

Accepted Answer

ATP

Answer

Glycogen

Answer

Creatine phosphate

Answer

Glucose

Question 42

Which theory most accurately describes the mechanism of muscle contraction?

Accepted Answer

Sliding Filament Theory

Answer

Thermal Theory

Answer

Electrical Theory

Answer

Chemical Theory

Question 43

What is the primary function of the myosin head during muscle contraction?

Accepted Answer

Binds to actin and hydrolyzes ATP

Answer

Generates electrical impulses

Answer

Releases calcium ions

Answer

Stores neurotransmitters

Question 44

Which type of muscle contraction involves the shortening of the muscle?

Accepted Answer

Concentric

Answer

Plyometric

Answer

Eccentric

Answer

Isometric

Question 45

Which neurotransmitter is released at the neuromuscular junction to initiate muscle contraction?

Accepted Answer

Acetylcholine

Answer

Dopamine

Answer

Norepinephrine

Answer

Serotonin

Question 46

What is the primary role of the sarcoplasmic reticulum in muscle contraction?

Accepted Answer

Stores and releases calcium ions

Answer

Conducts electrical impulses

Answer

Synthesizes ATP

Question 47

Which of the following characteristics is associated with slow-twitch muscle fibers?

Accepted Answer

High endurance capacity

Answer

High force production

Answer

Fast contraction speed

Question 48

How does understanding muscle contraction enhance nursing practice?

Accepted Answer

Guides interventions for optimizing muscle function and preventing complications

Answer

Only applies to physical therapy

Answer

It has no clinical implications