Muscular System Practice Questions

What is the name of the outermost layer of connective tissue surrounding a skeletal muscle?

A. Epimysium

B. Perimysium

C. Endomysium

D. Sarcolemma

A. Epimysium

Myofibrils are composed primarily of__________.

A. actin and myosin

B. perimysium and endomysium

C. troponin and tropomyosin

D. fascia and tendons

A. actin and myosin

What causes the striated appearance of skeletal muscle fibers?

A. Arrangement of transverse tubules

B. Position of the sarcoplasmic reticulum network

C. Organization of components of the sarcomeres

D. Location of the cisternae

C. Organization of components of the sarcomeres

Which statement describes a sarcomere?

A. A segment of the sarcoplasmic reticulum

B. A group of fascicles

C. group of muscle fibers

D. A segment of a muscle fiber

D. A segment of a muscle fiber

Which connective tissue layer is comprised of loose connective tissue?

A. Perimysium

B. Fascia

C. Epimysium

D. Endomysium

D. Endomysium

A tendon is__________, whereas an aponeurosis is__________.

A. cordlike and connects bones to bones; a broad sheet of dense connective tissue that connects muscles to muscles

B. a broad sheet of dense connective tissue that connects muscles to muscles; cordlike and connects bones to bones

C. cordlike and connects muscles to bones; a broad sheet of dense connective tissue that connects muscles to muscles

D. a broad sheet of dense connective tissue that connects bones to bones; cordlike and connects muscles to muscles

C. cordlike and connects muscles to bones; a broad sheet of dense connective tissue that connects muscles to muscles

What makes up muscle fibers?

A. Muscles

B. Sarcomeres

C. Connective tissue fibers

D. Synapses

B. Sarcomeres

Unlike smooth muscle cells, the__________ of skeletal and cardiac muscle cells are well developed.

A. ribosomes and mitochondria

B. nuclei and Golgi apparatus

C. sacrolemma and cisternae

D. transverse tubules and sarcoplasmic reticulum

D. transverse tubules and sarcoplasmic reticulum

Which of these options lists the structures in order, from smallest to largest?

A. Myofibril, filament, muscle, fascicle, muscle fiber

B. Fascicle, filament, muscle fiber, myofibril, muscle

C. Filament, myofibril, muscle fiber, fascicle, muscle

D. Filament, muscle fiber, myofibril, fascicle, muscle

C. Filament, myofibril, muscle fiber, fascicle, muscle

Which of these options lists the structures in order, from deepest to most superficial?

A. Perimysium, epimysium, endomysium, fascia

B. Fascia, endomysium, perimysium, epimysium

C. Fascia, epimysium, perimysium, endomysium

D. Endomysium, perimysium, epimysium, fascia

D. Endomysium, perimysium, epimysium, fascia

What is the functional unit of muscle contraction?

A. Muscle

B. Muscle fiber

C. Myosin cross-bridge

D. Sarcomere

D. Sarcomere

What is the location of the vesicles containing neurotransmitter molecules?

A. Along the side of the myofibrils

B. Deep to the motor end plate

C. Within the cisternae

D. At distal end of motor axon

D. At distal end of motor axon

The amount of oxygen that liver cells require to support the conversion of lactic acid to glucose or glycogen is called the__________.

A. refractory quantity

B. oxygen debt

C. anaerobic concentration

D. aerobic conversion

B. oxygen debt

After finishing a sprint, Tawanda experiences painful cramps in her calf muscles. A deficit in__________ would explain her cramping.

A. actin

B. acetylcholine

C. ATP

D. ADP

C. ATP

What binds to the exposed cross-bridges on actin?

A. ATP

B. Myosin

C. Calcium

D. Acetylcholine

B. Myosin

Name the area of the sarcolemma that is part of a neuromuscular junction.

A. Motor neuron

B. M line

C.Cisterna

D. Motor end plate

D. Motor end plate

What occurs at a neuromuscular junction?

A. Actin and myosin filaments slide past one another.

B. Troponin and tropomyosin cover and uncover actin binding sites.

C. Neurotransmitters are released.

D. Calcium channels open when calcium ions bind to them.

C. Neurotransmitters are released.

Many muscles are named for their location in the body, particularly in relation to bones. In what body region would you expect to find the frontalis muscle?

A. The thoracic region

B. The abdominal region

C. The pelvic region

D. The cranial region

D. The cranial region

As Brittany was kayaking, she suddenly experienced extreme pain in her upper arm and can no longer extend at the elbow joint. What muscle has likely been injured?

A. Biceps brachii

B. Brachioradialis

C. Triceps brachii

D. Supinator

C. Triceps brachii

Which of these events occurs first in muscle fiber contraction?

A. The muscle fiber membrane is stimulated and a muscle impulse travels deep into the fiber through transverse tubules.

B. Acetylcholine diffuses across a gap at a neuromuscular junction.

C. Acetylcholine is released from the axon of the motor neuron.

D. Calcium ions diffuse from sarcoplasmic reticulum into the sarcoplasm and bind to troponin molecules.

C. Acetylcholine is released from the axon of the motor neuron.

Which statement describes the mechanism of muscle contraction?

A. Tropomyosin molecules move and expose specific binding sites on thick filaments.

B. Actin filaments slide along myosin filaments.

C. Cross-bridges form between actin and the sarcolemma.

D. Filaments of troponin and tropomyosin slide past one another.

B. Actin filaments slide along myosin filaments.

Muscle fibers generally have only one motor end plate, but a single motor neuron can innervate many different muscle fibers in a group. How does this arrangement affect muscle contraction?

A. Any one muscle fiber can be stimulated by multiple motor neurons, allowing for wide variation in muscle fiber function.

B. When a motor neuron transmits a signal, only one fiber will contract with strong force.

C. A signal from one motor neuron can potentially stimulate multiple fibers in a group to contract, generating more force.

D. When one muscle fiber contracts, it causes the motor neuron to stimulate the other muscle fibers that it innervates.

C. A signal from one motor neuron can potentially stimulate multiple fibers in a group to contract, generating more force.

A__________ is the functional connection between a neuron and a skeletal muscle fiber.

A. synapse

B. sarcolemma

C. neuroma

D. dendrite

A. synapse

Arrange the steps of muscle fiber contraction in the correct order:

1. The muscle impulse reaches the sarcoplasmic reticulum and calcium is released.
2. Thin filaments are pulled over the thick filaments.
3. Calcium floods the sarcoplasm and binds to troponin molecules leaving active sites.
4. The impulse arrives at the synapse and travels through the transverse tubules.
5. The muscle fiber shortens and contracts.
6. Myosin heads bind to exposed active sites on actin, forming cross-bridges.

A. 4, 1, 3, 5, 6, 2

B. 4, 1, 3, 2, 6, 5

C. 4, 1, 3, 6, 2, 5

D. 4, 3, 6, 2, 5, 1

C. 4, 1, 3, 6, 2, 5

Why does oxygen debt develop?

A. The respiratory and circulatory systems are unable to supply enough oxygen for skeletal muscles to work strenuously for a minute or two.

B. Myoglobin molecules are unable to store the amount of oxygen needed for skeletal muscles to work strenuously for a minute or two.

C. Too much oxygen is used to form pyruvic acid when skeletal muscles work strenuously for a minute or two.

D. The concentration of oxygen in the atmosphere is too low to meet the needs of skeletal muscles working strenuously for a minute or two.

A. The respiratory and circulatory systems are unable to supply enough oxygen for skeletal muscles to work strenuously for a minute or two.

The characteristic reddish brown color of skeletal muscle is due to the presence of which substance?

A. Creatine phosphate

B. Myosin

C. Myoglobin

D. Calcium

C. Myoglobin

What is a motor unit?

A. Many myofibrils contained within a sarcolemma

B. The multiple folds of the motor end plate at a neuromuscular junction

C. A motor neuron and the muscle fibers it innervates

D. All muscles and other structures encased within a fascia

C. A motor neuron and the muscle fibers it innervates

During a muscle contraction, why is ATP required?

A. To synthesize creatine phosphate

B. To breakdown glycogen into glucose for fuel

C. To allow myofilament movement

D. To stimulate enzyme activity

C. To allow myofilament movement

How do skeletal muscles help maintain body temperature?

A. Excess body heat is used to increase muscle function.

B. Muscle contraction releases heat.

C. Excess acetylcholine is metabolized, releasing heat.

D. The movement of thin filaments over thick filaments uses up some body heat.

B. Muscle contraction releases heat.

Doing a "plank" is often part of a yoga or Pilates workout. It is done by holding the body straight in a prone position, engaging the abdominal muscles and supporting oneself on arms and toes. It is much like the "up" position of a push-up, but is held for 30 to 60 seconds. What type of contraction would be occurring in the abdominal muscles?

A. Isotonic contraction

B. Eccentric contraction

C. Isometric contraction

D. Concentric contraction

C. Isometric contraction

What features are not present in smooth muscle?

A. Actin and myosin

B. Transverse tubules and striations

C. Myofibrils

D. Nuclei and mitochondria

B. Transverse tubules and striations

What happens in a muscle as it undergoes atrophy in response to disuse?

A. Motor neurons grow and invade the muscle abnormally.

B. The size of actin and myosin filaments decreases.

C. Capillaries within the muscle rupture.

D. The muscle swells.

B. The size of actin and myosin filaments decreases.

How does smooth muscle compare to skeletal muscle?

A. Smooth muscle contracts more slowly and relaxes more slowly.

B. Smooth muscle contracts more slowly and relaxes more rapidly.

C. Smooth muscle contracts more rapidly and relaxes more slowly.

D. Smooth muscle contracts more rapidly and relaxes more rapidly.

A. Smooth muscle contracts more slowly and relaxes more slowly.

While examining a sample of muscle tissue under a microscope, you notice that the cells have a single nucleus. The fibers are striated and heavily branched. Which muscle type does this sample contain?

A. Skeletal muscle

B. Smooth muscle

C. Cardiac muscle

C. Cardiac muscle

While examining a sample of muscle tissue under a microscope, you notice that the cells are striated, long, unbranched, and multinucleated. Which muscle type does this sample contain?

A. Skeletal muscle

B. Smooth muscle

C. Cardiac muscle

A. Skeletal muscle

Muscle cells that are short in length and have centrally located nuclei are__________ muscle cells.

A. smooth

B. skeletal

C. cardiac

A. smooth

What structures connect cardiac muscle cells together?

A. Intervertebral discs

B. Neuromuscular junctions

C. Intercalated discs

D. Motor end plates

C. Intercalated discs

Which statement describes cardiac muscle?

A. The cells are multinucleated.

B. It does not require stimulation by motor neurons.

C. The cells contains very few mitochondria.

D. It lacks the straitions formed by regularly arranged sarcomeres.

B. It does not require stimulation by motor neurons.

What term describes the more movable end of a muscle?

A. Origin

B. Fulcrum

C. Insertion

D. Source

C. Insertion

In producing a movement, the muscle that causes an action is acting as the__________.

A. synergis

B. synergis

C. agonist

D. mediator

C. agonist

In many movements, the agonist is assisted by other muscles. A muscle that assists the agonist is called a(n)__________.

A. antagonist

B. prime mover

C. mediator

D. synergist

D. synergist

What is the linea alba?

A. A muscle extending from the ischial spine to the coccyx and sacrum

B. A curved, broad muscle on the side of the chest

C. A strip of tough connective tissue covering the top of the cranium

D. A band of tough connective tissue on the midline of the abdomen

D. A band of tough connective tissue on the midline of the abdomen

A muscular contraction in which the muscle shortens, moving an object, is called a(n)__________ contraction.

A. concentric

B. eccentric

C. isometric

D. tetanic

A. concentric

Endomysium separates individual muscle fibers from each other.

A. True

B. False

B. False

ATP is necessary for muscle relaxation.

A. True

B. False

A. True