Muscles: Structure and Function - Anatomy and Physiology II Quiz

Question 1

Which of the following is the main function of skeletal muscle?

Accepted Answer

Moving the body

Answer

Pumping blood

Answer

Controlling body temperature

Question 2

What feature is exclusive to cardiac muscle cells?

Accepted Answer

Intercalated discs

Answer

Branched appearance

Answer

Multinucleated

Answer

Voluntary control

Question 3

Describe the structural characteristics of smooth muscle cells and explain how these characteristics relate to their functions.

Accepted Answer

Smooth muscle cells are spindle-shaped, uninucleated, and lack striations.

Answer

Smooth muscle cells are striated, multinucleated, and have intercalated discs.

Answer

Smooth muscle cells have a branched appearance, lack nuclei, and possess striations.

Answer

Smooth muscle cells are rectangular, have multiple nuclei, and exhibit striations.

Question 4

Which structural component of a muscle represents the smallest functional unit?

Accepted Answer

Sarcomere

Answer

Myofibril

Answer

Myofilament

Answer

Muscle fiber

Question 5

Identify the neurotransmitter that plays a crucial role in transmitting nerve impulses to muscles, initiating contraction.

Accepted Answer

Acetylcholine

Answer

Dopamine

Answer

Epinephrine

Answer

Serotonin

Question 6

Which molecule serves as the immediate energy source for muscle contraction, providing the necessary energy for muscle movement?

Accepted Answer

ATP

Answer

Glucose

Answer

Glycogen

Answer

Creatine phosphate

Question 7

Which mechanism is primarily responsible for muscle fatigue during intense exercise?

Accepted Answer

ATP depletion

Answer

Lactate buildup

Answer

Oxygen shortage

Question 8

Which type of muscle fiber is primarily responsible for endurance activities, allowing for sustained muscle activity over an extended period?

Accepted Answer

Type I muscle fibers

Answer

Type IIa muscle fibers

Answer

Type IIb muscle fibers

Answer

Type IIx muscle fibers

Question 9

Which type of muscle is found in the walls of organs such as the stomach and intestines, allowing for involuntary rhythmic contractions?

Accepted Answer

Smooth muscle

Answer

Skeletal muscle

Answer

Cardiac muscle

Answer

Voluntary muscle

Question 10

What is the primary function of the sarcoplasmic reticulum in muscle cells?

Accepted Answer

To store and release calcium ions, which are crucial for muscle contraction

Answer

To synthesize proteins necessary for muscle growth and repair

Answer

To generate ATP, the energy currency of cells

Answer

To transmit nerve impulses to muscle fibers

Question 11

Which of the following hormones plays a key role in muscle growth and development?

Accepted Answer

Testosterone

Answer

Estrogen

Answer

Insulin

Answer

Thyroid hormone

Question 12

What is the name of the specialized junction where motor neurons connect to muscle fibers, transmitting signals for muscle contraction?

Accepted Answer

Myoneural junction

Answer

Synapse

Answer

Synaptic cleft

Answer

Axon terminal

Question 13

Which of the following is a common muscular disorder characterized by muscle weakness and fatigue due to a lack of acetylcholine, the neurotransmitter responsible for muscle contraction?

Accepted Answer

Myasthenia gravis

Answer

Amyotrophic lateral sclerosis

Answer

Parkinson's disease

Answer

Huntington's disease

Question 14

What is the primary neurotransmitter released by motor neurons to initiate muscle contraction?

Accepted Answer

Acetylcholine

Answer

Dopamine

Answer

Serotonin

Answer

Norepinephrine

Question 15

Which type of exercise is most effective for building muscle mass through resistance training?

Accepted Answer

Resistance training

Answer

Cardio training

Answer

Flexibility training

Answer

Balance training

Question 16

What is the role of the cytoskeleton in muscle cells?

Accepted Answer

To provide структурную поддержку, shape, and internal organization

Answer

To facilitate muscle contraction

Answer

To store energy

Answer

To transport nutrients

Question 17

Which of the following is NOT a recognized type of muscle tissue?

Accepted Answer

Visceral

Answer

Skeletal

Answer

Smooth

Answer

Cardiac

Question 18

The functional unit of a muscle fiber, responsible for contraction, is termed the:

Accepted Answer

Sarcomere

Answer

Myofibril

Answer

Myofilament

Answer

Tropomyosin

Question 19

During muscle contraction, which ion is released from the sarcoplasmic reticulum to initiate the process?

Accepted Answer

Calcium

Answer

Sodium

Answer

Potassium

Answer

Chloride

Question 20

At the neuromuscular junction, the neurotransmitter responsible for transmitting signals from nerves to muscles is:

Accepted Answer

Acetylcholine

Answer

Dopamine

Answer

Serotonin

Answer

Epinephrine

Question 21

The primary function of smooth muscle tissue in the body is:

Accepted Answer

Maintaining organ shape and regulating flow

Answer

Voluntary movement

Answer

Generating heat

Answer

Supporting the skeleton

Question 22

A characteristic feature of cardiac muscle tissue that allows for coordinated contractions is:

Accepted Answer

Intercalated discs

Answer

Voluntary control

Answer

Branched cells

Answer

Multinucleated cells

Question 23

Which muscle group is primarily responsible for extending the leg at the knee joint?

Accepted Answer

Quadriceps femoris

Answer

Hamstrings

Answer

Calves

Answer

Gluteus maximus

Question 24

A muscle strain refers to an injury involving damage to:

Accepted Answer

Muscle fibers

Answer

Ligaments

Answer

Tendons

Answer

Bones

Question 25

Which of these is a hallmark symptom of muscular dystrophy?

Accepted Answer

Gradual, painless muscle weakness

Answer

Sudden, severe muscle weakness

Answer

Intense muscle pain

Answer

Increased muscle size

Question 26

Which of the following is NOT involved in regulating skeletal muscle contraction?

Accepted Answer

Mitochondria

Answer

Nervous system

Answer

Hormones

Answer

Autocrine/paracrine factors

Question 27

Myasthenia gravis is characterized by which of the following pathophysiological mechanisms and clinical presentations?

Accepted Answer

Defective acetylcholine receptors impairing neuromuscular transmission, leading to muscle weakness that worsens with repeated use.

Answer

Excessive acetylcholine release causing muscle cramps and spasms due to overstimulation of muscle fibers.

Answer

Denervation of muscle fibers due to peripheral nerve damage, resulting in muscle atrophy and loss of function.

Answer

Myofibril damage and inflammation causing muscle pain, stiffness, and weakness.

Question 28

Identify the characteristic that correctly describes smooth muscle tissue:

Accepted Answer

Primarily found in the walls of organs and blood vessels

Answer

Appears striated and multinucleated

Answer

Responsible for conscious muscle movements

Question 29

Which of the following is the smallest structural unit within a muscle fiber responsible for contraction?

Accepted Answer

Sarcomere

Answer

Myofibril

Answer

Motor unit

Answer

Myofilament

Question 30

What protein forms the thin filaments and plays a crucial role in muscle contraction?

Accepted Answer

Actin

Answer

Tropomyosin

Answer

Troponin

Answer

Myosin

Question 31

Which type of muscle tissue exhibits involuntary contractions, is found in the walls of hollow organs, and lacks striations?

Accepted Answer

Smooth muscle

Answer

Cardiac muscle

Answer

Voluntary muscle

Answer

Skeletal muscle

Question 32

What is the physiological process by which muscles generate force and movement?

Accepted Answer

Muscle contraction

Answer

Muscle hypertrophy

Answer

Muscle atrophy

Answer

Muscle relaxation

Question 33

Which neurotransmitter is released at the neuromuscular junction, triggering muscle contraction?

Accepted Answer

Acetylcholine

Answer

Serotonin

Answer

Dopamine

Answer

Epinephrine

Question 34

Which muscle group is primarily responsible for extending the knee joint?

Accepted Answer

Quadriceps

Answer

Calves

Answer

Hamstrings

Answer

Glutes

Question 35

What process refers to an increase in the size of muscle cells?

Accepted Answer

Hypertrophy

Answer

Atrophy

Answer

Metaplasia

Answer

Hyperplasia

Question 36

Which of the following is a common cause of muscle strain?

Accepted Answer

Overexertion

Answer

Vitamin deficiency

Answer

Muscle disease

Answer

Dehydration

Question 37

Identify the functional unit of a muscle responsible for contraction.

Accepted Answer

Sarcomere

Answer

Motor unit

Answer

Myofilament

Answer

Myofibril

Question 38

Which type of muscle tissue is primarily responsible for voluntary movements of the body?

Accepted Answer

Skeletal muscle

Answer

Striated muscle

Answer

Cardiac muscle

Answer

Smooth muscle

Question 39

Identify the unique characteristic of cardiac muscle that distinguishes it from other muscle types.

Accepted Answer

Syncytium

Answer

Branched

Answer

Striated

Answer

Involuntary

Question 40

Identify the neurotransmitter responsible for initiating muscle contraction at the neuromuscular junction.

Accepted Answer

Acetylcholine

Answer

Norepinephrine

Answer

Serotonin

Answer

Dopamine

Question 41

Which molecule serves as the primary energy source for muscle contraction?

Accepted Answer

ATP

Answer

Creatine phosphate

Answer

Glucose

Answer

Glycogen

Question 42

Classify the type of muscle contraction characterized by a shortening of the muscle length.

Accepted Answer

Concentric

Answer

Eccentric

Answer

Isokinetic

Answer

Isometric

Question 43

Describe the primary function of the sarcoplasmic reticulum in muscle cells.

Accepted Answer

Stores and releases calcium ions, triggering muscle contraction.

Answer

Conducts electrical signals across the muscle cell.

Answer

Synthesizes proteins essential for muscle development.

Question 44

Identify the type of muscle fiber optimally suited for prolonged, low-intensity physical activities.

Accepted Answer

Type I (slow-twitch)

Answer

Type IIb (super-fast-twitch)

Answer

Type IIx (fast-twitch, glycolytic)

Answer

Type IIa (fast-twitch, oxidative)

Question 45

State the primary role of skeletal muscles in the human body.

Accepted Answer

Generate force and facilitate movement

Answer

Regulate body temperature

Answer

Produce hormones

Answer

Store energy

Question 46

Which of the following is NOT a type of muscle tissue?

Accepted Answer

Epithelial tissue

Answer

Skeletal muscle

Answer

Smooth muscle

Answer

Cardiac muscle

Question 47

The fundamental unit of skeletal muscle is known as:

Accepted Answer

Sarcomere

Answer

Myofibril

Answer

Actin

Answer

Myofilament

Question 48

Which protein is primarily responsible for muscle contraction?

Accepted Answer

Myosin

Answer

Tropomyosin

Answer

Actin

Answer

Troponin

Question 49

When a muscle shortens during contraction, it is known as:

Accepted Answer

Concentric contraction

Answer

Isometric contraction

Answer

Eccentric contraction

Answer

Isokinetic contraction

Question 50

Which hormone has anabolic effects on muscle tissue, promoting growth and development?

Accepted Answer

Testosterone

Answer

Insulin

Answer

Estrogen

Question 51

Which of the following is a common soft tissue injury involving muscle fibers?

Accepted Answer

Strain

Answer

Sprain

Answer

Fracture

Answer

Dislocation

Question 52

What is the primary site of communication between a motor neuron and a muscle cell?

Accepted Answer

Neuromuscular junction

Answer

Motor-sensory junction

Answer

Sensory-muscle junction

Answer

Neuron-neuron junction