Which of the following describes voluntary muscle tissue

1 of 50

Which of the following describes voluntary muscle tissue?

Smooth muscle

Cardiac muscle

Skeletal muscle

Dense irregular

Dense regular

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2 of 50

What does endomysium cover?

Smooth muscle only

Fascicles of muscle cells

An entire muscle

An individual muscle cell

Myofibrils

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3 of 50

What is the name of the plasma membrane of a skeletal muscle cell?

Sarcoplasm

Myofilament

Sarcomere

Sarcoplasmic reticulum

Sarcolemma

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4 of 50

Which of the following describes a sarcomere?

The contractile unit between two Z discs

The area between two intercalated discs

The wavy lines on the cell, as seen in a microscope

The nonfunctional unit of skeletal muscle

A compartment in a myofilament

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5 of 50

Which of the following lists the structures of the skeletal muscle in order from largest to smallest?

1. Fascicle Myofilament Muscle fiber (cell) Myofibril
2. Sarcomere

3, 2, 5, 4, 1

1, 3, 4, 5, 2

2, 5, 4, 3, 1

3, 1, 2, 4, 5

1, 4, 3, 2, 5

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6 of 50

What is acetylcholine?

A source of energy for muscle contraction

A component of thick myofilaments

An oxygen-binding protein

A neurotransmitter that stimulates skeletal muscle

An ion pump on the postsynaptic membrane

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7 of 50

What is the name of the gap between the axon terminal of a motor neuron and the sarcolemma of a skeletal muscle cell?

Cross bridge

Sarcomere

Synaptic cleft

Neuromuscular junction

Motor unit

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8 of 50

Why are calcium ions necessary for skeletal muscle contraction?

Calcium increases the action potential transmitted along the sarcolemma.

Calcium initiates the depolarization of the sarcolemma.

Calcium triggers the binding of myosin to actin.

Calcium makes the membrane more permeable to sodium ions.

Calcium causes ATP binding to actin.

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9 of 50

What generates the mechanical force of contraction?

The "accordion-like" folding of thin and thick filaments

The temporary disappearance of thin filaments

The shortening of the thin filaments

The sliding of thin filaments past thick ones

The shortening of the thick filaments

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10 of 50

What does a motor unit include?

Muscle fibers only

Motor neurons only

Several motor neurons and one muscle fiber

Several muscle fibers and one motor neuron

One muscle fiber and one nerve

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11 of 50

Which of the following describes when a muscle contracts so completely that no relaxation is seen while the contraction is sustained?

Tetanus

Incomplete tetanus

Twitch

A normal contraction

Summation

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12 of 50

How can the condition of skeletal muscle fatigue best be explained?

The inability to generate sufficient quantities of ATP due to feedback regulation of synthesis

Insufficient intracellular quantities of ATP due to excessive consumption of oxygen

The all-or-none law

The total lack of ATP

Inadequate numbers of mitochondria

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13 of 50

Anaerobic glycolysis occurs when which substance is lacking?

Glucose

Oxygen

ATP

Lactic acid

Carbon dioxide

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14 of 50

What do isometric contractions produce?

Contractions and shortening, but not movement

Movement

Contractions

Contractions and movement, but not shortening

Muscle shortening

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15 of 50

What is the name of the movement that decreases the angle between two bones?

Abduction

Flexion

Circumduction

Extension

Rotation

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16 of 50

While doing "jumping jacks" during an exercise class, the arms and legs move laterally away from the midline of the body. What is this motion called?

Adduction

Extension

Abduction

Circumduction

Flexion

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17 of 50

What is the name of a muscle group that works with and assists the action of a prime mover?

Antagonist and synergist

Fixator only

Antagonist only

Synergist only

Antagonist and fixator

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18 of 50

Which of the following muscles are examples of antagonists?

Biceps brachii and triceps brachii

Vastus medialis and vastus lateralis

Gastrocnemius and soleus

Masseter and temporalis

Biceps femoris and biceps brachii

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19 of 50

Which of the following muscle(s) closes the jaw?

Sternocleidomastoid

Zygomaticus

Buccinator

Frontalis

Both masseter and temporalis

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20 of 50

Which one of the following is the action of the orbicularis oris?

Pulls the lower lip down and back.

Allows blinking, squinting, and various other protective mechanisms for the eye.

Draws the eyebrows together.

Closes the jaw.

Closes, purses, and protrudes the lips.

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21 of 50

Which one of the following muscles is involved in abduction of the arm at the shoulder joint?

Triceps brachii

Biceps brachii

Pectoralis major

Deltoid

Latissimus dorsi

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22 of 50

Which of the following is a muscle located on the ventral (anterior) side of the body?

Pectoralis major

Occipitalis

Gluteus medius

Latissimus dorsi

Gastrocnemius

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23 of 50

What is the main function of the quadriceps femoris group?

Thigh abduction

Foot inversion

Arm flexion

Hand supination

Knee extension

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24 of 50

Which autoimmune muscle disease results from a shortage of acetylcholine receptors at the neuromuscular junction and leaves the patient with generalized muscle weakness and fatigue?

Multiple sclerosis

Muscular dystrophy

Scoliosis

Myasthenia gravis

Spina bifida

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25 of 50

What does the term central nervous system refers to?

Spinal cord and spinal nerves

Brain, spinal cord, and cranial nerves

Brain and spinal cord

Autonomic and peripheral nervous systems

Brain and cranial nerves