Assessment 10: Muscular System

Myofibrils are composed primarily of A. troponin and tropomyosin. B. actin and myosin. C. fascia and tendons. D. perimysium and endomysium.

actin and myosin

During skeletal muscle contraction, to what do myosin heads bind? A. Z discs B. actin filaments C. myosin filaments D. the H zone E. thick filaments

actin filaments

What is the unstoppable electrical current that travels down the length of the entire surface of a sarcolemma? A. neuromuscular junction B. acetylcholine C. action potential D. neurotransmitter

action potential

Which movement is opposite to abduction? A. circumduction B. rotation C. adduction D. flexion E. supination

adduction

Which muscle group adducts the thighs? A. adductor group B. fibularis muscles C. hamstring group D. gluteus muscles E. quadriceps group

adductor group

myasthenia gravis is A) a bacterial infection. B) a form of cancer. C) an autoimmune disorder. D) the result of injury.

an autoimmune disorder

What is covered by the endomysium? A. fascicles of muscle cells B. an individual muscle cell C. myofibrils D. an entire muscle E. smooth muscle only

an individual muscle cell

Which method of regenerating ATP during muscle contraction can produce lactic acid? A. anaerobic glycolysis B. creatine phosphate C. aerobic cellular respiration D. direct phosphorylation E. oxidative phosphorylation

anaerobic glycolysis

Organize the following muscular connective tissues from smallest to largest: epimysium, perimysium, fascia, endomysium. A) Deep fascia, endomysium, perimysium, epimysium B) Endomysium, perimysium, epimysium, deep fascia C) deep fascia, epimysium, perimysium, endomysium D) Perimysium, epimysium, endomysium, deep fascia

Endomysium, perimysium, epimysium, deep fascia

Which of the following statements is true? A. Fast fibers have a small diameter. B. Fast fibers contain loosely packed myofibrils. C. Fast fibers have large glycogen reserves. D. Fast fibers have many mitochondria.

Fast fibers have large glycogen reserves.

Which of the following statements describes smooth muscle cells? A. They are resistant to fatigue. B. They have a rapid onset of contractions. C. They cannot exhibit tetanus. D. They primarily use anaerobic metabolism.

They are resistant to fatigue.

A group of rats are bred in a laboratory to study muscle function. This group possesses a genetic defect that causes troponin to be incorrectly synthesized, making it non-functional. Because of this, the rats are entirely paralyzed. Which of the following correctly explains the impact of the defect on the muscle? A. Troponin, when revealed by actin, won't be able to bind to the myosin heads of the thick filament. B. Troponin, when revealed by tropomyosin, won't be able to bind to the myosin heads of the thick filament. C. Troponin won't pull away to reveal the actin binding spots of the thin filament after tropomyosin binds Ca+2. D. Troponin can't bind Ca+2, which stops tropomyosin from pulling away to reveal actin binding spots on the thin filament.

Troponin can't bind Ca+2, which stops tropomyosin from pulling away to reveal actin binding spots on the thin filament.

Which of the following is not a muscle of mastication? A) Temporalis B) Zygomaticus C) Medial and lateral pterygoid D) Masseter

Zygomaticus

The linea alba is: A. a band of tough connective tissue to which abdominal wall muscles attach. B. a curved, broad muscle on the side of the chest. C. a muscle extending from the ischial spine to the coccyx and sacrum. D. a muscle beneath the skull.

a band of tough connective tissue to which abdominal wall muscles attach

A motor unit is: A. many motor end plates at a neuromuscular junction. B. the functional unit of a muscle fiber. C. many myofibrils in a sarcolemma. D. a motor neuron and the muscle fibers it innervates

a motor neuron and the muscle fibers it innervates

While doing "jumping jacks" during an exercise class, your arms and legs move laterally away from the midline of your body. This motion is called ________. A. adduction B. flexion C. abduction D. extension E. circumduction

abduction

Specific neurotransmitter that stimulates skeletal muscle cells

acetylcholine

A sprinter would experience muscle fatigue sooner than a marathon runner due to ________. A. anaerobic metabolism in the muscles of the sprinter B. anaerobic metabolism in the muscles of the marathon runner C. aerobic metabolism in the muscles of the sprinter D. glycolysis in the muscles of the marathon runner

anaerobic metabolism in the muscles of the sprinter

Muscles that perform opposite actions to one another are termed ________. A. prime movers B. synergists C. antagonists D. fixators

antagonists

Which of the following properties is not common to all three muscle tissues? A. excitability B. the need for ATP C. at rest, uses shielding proteins to cover actin-binding sites D. elasticity

at rest, uses shielding proteins to cover actin-binding sites

Neurotransmitters are released upon stimulation from a nerve impulse from the ________. A. myofibrils B. axon terminals of the motor neuron C. thick filaments D. sarcolemma of the muscle cell E. sarcoplasmic reticulum

axon terminals of the motor neuron

Like the biceps brachii muscle, which muscle is a prime mover in elbow flexion? A. deltoid B. brachioradialis C. triceps brachii D. fibularis longus E. brachialis

brachialis

A nursing infant develops a powerful sucking muscle that adults also use for whistling or blowing a trumpet called the ________. A. buccinator B. temporalis C. masseter D. platysma E. zygomaticus

buccinator

Which element is important in directly triggering contraction? A. sodium (Na+) B. calcium (Ca++) C. potassium (K+) D. chloride (Cl-)

calcium (Ca++)

The sarcoplasmic reticulum stores this chemical

calcium ions

Muscle relaxation occurs when ________. A. calcium ions are actively transported out of the sarcoplasmic reticulum B. calcium ions diffuse out of the sarcoplasmic reticulum C. calcium ions are actively transported into the sarcoplasmic reticulum D. calcium ions diffuse into the sarcoplasmic reticulum

calcium ions are actively transported into the sarcoplasmic reticulum

Cardiac muscles differ from skeletal muscles in that they ________. A. are striated B. utilize aerobic metabolism C. contain myofibrils D. contain intercalated discs

contain intercalated discs

During which phase of a twitch in a muscle fiber is tension the greatest? A. resting phase B. repolarization phase C. contraction phase D. relaxation phase

contraction phrase

The correct order for the smallest to the largest unit of organization in muscle tissue is ________. A. fascicle, filament, muscle fiber, myofibril B. filament, myofibril, muscle fiber, fascicle C. muscle fiber, fascicle, filament, myofibril D. myofibril, muscle fiber, filament, fascicle

filament, myofibril, muscle fiber, fascicle

A runner collapses during a race and is examined by a doctor. They have lost the ability to plantar flex at the ankle. Which of the following is probably the injured muscle? A. Semimembranosus B. Biceps femoris C. Tibialis anterior D. Gastrocnemius

gastrocnemius

Which muscle forms the curved calf of the posterior leg? A. fibularis longus B. gastrocnemius C. soleus D. rectus femoris E. tibialis anterior

gastrocnemius

Paralysis of which of the following would make an individual unable to flex the hip? A. iliopsoas B. biceps femoris C. gastrocnemius D. soleus E. tibialis anterior

iliopsoas

The more movable end of a muscle is its: A. source. B. insertion. C. fulcrum. D. origin.

insertion

The structures that connect cardiac muscle cells are A. intercalated discs. B. neuromuscular junctions. C. intervertebral discs. D. motor end plates.

intercalated discs

Contractions in which muscles shorten and produce movement are known as ________. A. resistance exercises B. twitches C. isometric contractions D. isotonic contractions

isotonic contractions

Smooth muscles differ from skeletal and cardiac muscles in that they ________. A. lack myofibrils B. are under voluntary control C. lack myosin D. lack actin

lack myofibrils

Which of the following is a type isometric exercise in which muscles increase in size and strength? A. jogging B. biking C. dancing D. lifting weights E. swimming

lifting weights

Which one of the following is NOT a criterion generally used in naming muscles? A. action of the muscle B. method of attachment of the muscle to bone C. shape of the muscle D. relative size of the muscle E. number of origins of the muscle

method of attachment of the muscle to bone

At a neuromuscular junction, the muscle fiber membrane folds, forming a A. motor unit. B. motor neuron. C. motor end plate. D. neurotransmitter.

motor end plate

Neurotransmitters are stored in vesicles in A. myofibrils. B. motor neuron endings. C. motor units. D. motor end plates.

motor neuron endings

An example of a partial but sustained contraction is A. eye blinking. B. a twitch. C. muscle tone. D. knee jerking.

muscle tone

An inherited disease that causes muscles to degenerate and atrophy is known as ________. A. muscular dystrophy B. cystic fibrosis C. torticollis D. myasthenia gravis

muscular dystrophy

From which embryonic cell type does muscle tissue develop? A. ganglion cells B. myotube cells C. myoblast cells D. satellite cells

myoblast cells

The characteristic reddish brown color of skeletal muscle comes from which substance? A. Myosin B. Calcium C. Myoglobin D. Actin

myoglobin

Binding sites on the surface of actin allow the formation of cross-bridges with molecules of A) ATP. B) tropomyosin. C) troponin D) myosin

myosin

Drug X blocks ATP regeneration from ADP and phosphate. How will muscle cells respond to this drug? A. by absorbing ATP from the bloodstream B. by using ADP as an energy source C. by using glycogen as an energy source D. none of the above

none of the above

The amount of oxygen liver cells require to support the conversion of lactic acid to produce glucose or glycogen is the A. aerobic conversion. B. oxygen debt. C. anaerobic concentration. D. refractory quantity.

oxygen debt

What aspect of creatine phosphate allows it to supply energy to muscles? A. ATPase activity B. phosphate bonds C. carbon bonds D. hydrogen bonds

phosphate bonds

The toxin that causes botulism: A. prevents release of acetylcholine. B. prevents decomposition of acetylcholine. C. decomposes acetylcholine. D. promotes release of acetylcholine.

prevents release of acetylcholine.

Functions of muscles include A. pumping blood. B. cushioning tissues from blunt force. C. generating electrical impulses. D. storage of minerals.

pumping blood

The increase in the number of motor units activated as a result of more intense stimulation is called A. threshold stimulation. B. recruitment. C. sustained contraction. D. latency.

recruitment

The discoloration and swelling that occurs with a muscle strain is due to A. excess myofibrils. B. separated tendons. C. severed nerves. D. ruptured blood vessels.

ruptured blood vessels

Muscle fibers are basically a collection of: A. sarcomeres. B. connective tissue fibers. C. synapses. D. muscles.

sacromeres

The cell membrane of a muscle fiber is called ________. A. myofibril B. sarcolemma C. sarcoplasm D. myofilament

sarcolemma

The striated appearance of skeletal muscle fibers results from the A) sarcoplasmic reticulum network. B) sarcomere organization. C) cisternae placement D) transverse tubule pattern

sarcomere organization

Thin and thick filaments are organized into functional units called ________. A. myofibrils B. myofilaments C. T-tubules D. sarcomeres

sarcomeres

What organelle wraps and surrounds the myofibril and stores calcium? A. sarcomere B. sarcolemma C. sarcoplasmic reticulum D. cross bridge

sarcoplasmic reticulum

Which cell type helps to repair injured muscle fibers? A. ganglion cells B. myotube cells C. myoblast cells D. satellite cells

satellite cells

Which type of muscle tissue contracts most quickly upon stimulation? A. smooth B. skeletal C. visceral D. cardiac E. tendons

skeletal

voluntary muscle tissue

skeletal muscle tissue

Activities such as distance swimming and distance running will most likely stimulate development of A. slow fatigue-resistant fibers. B. fast fatigue-resistant fibers. C. slow fatigable muscle fibers. D. fast fatigable muscle fibers.

slow fatigue-resistant fibers

Muscle tissue that dilates and constricts the pupils of our eyes

smooth muscle tissue

Cation that enters a muscle cell upon excitation

sodium ions

What must rush into a muscle cell to promote its depolarization? A. potassium ions B. acetylcholinesterase C. sodium ions D. acetylcholine E. calcium ions

sodium ions

If cardiac muscle cells were prevented from undergoing aerobic metabolism, they ultimately would ________. A. undergo glycolysis B. synthesize ATP C. stop contracting D. start contracting

stop contracting

Creatine phosphate (CP) functions within the muscle cells by ________. A. storing energy that will be transferred to ATP to resynthesize ADP as needed B. forming a temporary chemical compound with myosin C. inducing a conformational change in the myofilaments D. storing energy that will be transferred to ADP to resynthesize ATP as needed E. forming a chemical compound with actin

storing energy that will be transferred to ADP to resynthesize ATP as needed

Muscle that has a striped appearance is described as being ________. A. elastic B. nonstriated C. excitable D. striated

striated

A group of rats are bred in a laboratory to study muscle function. This group possesses a genetic defect that causes the myosin heads to bind ADP irreversibly. The rats are entirely paralyzed. Which of the following correctly explains the impact of the defect on the muscle? A. Because ADP is permanently bound, the myosin heads will be irreversibly cross-bridged with the actin binding sites of the thin filament. B. ATP won't bind to the myosin heads, causing the thin filament to be constantly pulled in the power stroke of contraction. C. ATP won't bind to the myosin heads, preventing the actin binding site of the thick filament from being revealed. D. Because ADP is permanently bound, the myosin heads can never bind to the actin binding sites of the thin filament.

Because ADP is permanently bound, the myosin heads will be irreversibly cross-bridged with the actin binding sites of the thin filament.

Creatine phosphate A) causes the decomposition of ADP. B) supplies energy for the breakdown of ATP to ADP. C) causes the decomposition of ATP. D) supplies energy for the synthesis of ATP

supplies energy for the synthesis of ATP

A sarcomere is ________. A. the wavy lines on the cell, as seen in a microscope B. a compartment in a myofilament C. the nonfunctional unit of skeletal muscle D. the area between two intercalated discs E. the contractile unit between two Z discs

the contractile unit between two Z discs

Many muscles are named for their location (origin and insertion) in the body, particularly in relation to bones. In what body region would you expect the frontalis muscle to originate? A. The abdominal region B. The cranium C. The pelvic region D. The thoracic region

the cranium

Depolarization of the sarcolemma means ________. A. the inside of the membrane has become less negative as sodium ions accumulate B. the outside of the membrane has become less negative as sodium ions accumulate C. the inside of the membrane has become more negative as sodium ions accumulate D. the sarcolemma has completely lost any electrical charge

the inside of the membrane has become less negative as sodium ions accumulate

A skeletal muscle twitch differs from a tetanic contraction in that ________. A. the muscle twitch occurs only in small muscles while a tetanic contraction occurs in large muscle groups B. the muscle twitch is prolonged and continuous while a tetanic contraction is brief and "jerky" C. the muscle twitch is a brief and "jerky" movement, while the tetanic contraction is prolonged and continuous D. the tetanic contraction is caused by a single stimulus, while the twitch is caused by very rapid multiple stimuli E. the tetanic contraction is considered abnormal, while the twitch is a normal muscle response

the muscle twitch is a brief and "jerky" movement, while the tetanic contraction is prolonged and continuous

Which facial muscle is considered the "smiling" muscle since it raises the corners of the mouth? A. orbicularis oris B. zygomaticus C. orbicularis oculi D. frontalis

zygomaticus

The muscles of a professional marathon runner are most likely to have ________. A. 80 percent fast-twitch muscle fibers and 20 percent slow-twitch muscle fibers B. 20 percent fast-twitch muscle fibers and 80 percent slow-twitch muscle fibers C. 50 percent fast-twitch muscle fibers and 50 percent slow-twitch muscle fibers D. 40 percent fast-twitch muscle fibers and 60 percent slow-twitch muscle fibers

20 percent fast-twitch muscle and 80 percent slow-twitch muscle fibers

Arrange the following steps of muscle fiber contraction in the correct sequence. 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, 2, 6, 5 B. 4, 1, 3, 6, 2, 5 C. 4, 1, 3, 5, 6, 2 D. 4, 3, 6, 2, 5, 1

4, 1, 3, 6, 2, 5

The muscles of a professional sprinter are most likely to have ________. A. 80 percent fast-twitch muscle fibers and 20 percent slow-twitch muscle fibers B. 20 percent fast-twitch muscle fibers and 80 percent slow-twitch muscle fibers C. 50 percent fast-twitch muscle fibers and 50 percent slow-twitch muscle fibers D. 40 percent fast-twitch muscle fibers and 60 percent slow-twitch muscle fibers

80 percent fast-twitch muscle fibers and 20 percent slow-twitch muscle fibers

According to the sliding filament model, binding sites on actin open when ________. A. creatine phosphate levels rise B. ATP levels rise C. acetylcholine levels rise D. calcium ion levels rise

Calcium ion levels rise

During muscle contraction, the cross-bridge detaches when ________. A. the myosin head binds to an ADP molecule B. the myosin head binds to an ATP molecule C. calcium ions bind to troponin D. calcium ions bind to actin

Calcium ions bind to troponin

According to the sliding filament theory, how does muscle contraction occur? A. Both thick and thin filaments shorten as the muscle contracts. B. Myosin heads attach and detach from thin filaments, causing thin filaments to shorten. C. Myosin heads form cross bridges and pull actin filaments, causing them to slide. D. A bands bunch up and shorten as myosin heads attach to thin filaments.

Myosin heads form cross bridges and pull actin filaments, causing them to slide.

Which of the following is not true? A) Red fibers contract more slowly than white. B) Red fibers have fewer mitochondria than white. C) Red fibers contain more myoglobin than white. D) Red fibers fatigue more slowly than white

Red fibers have fewer mitochondria than white

Which of the following statements is false? A. Slow fibers have a small network of capillaries. B. Slow fibers contain the pigment myoglobin. C. Slow fibers contain a large number of mitochondria. D. Slow fibers contract for extended periods.

Slow fibers have a small network of capillaries.

The soleus is a muscle that forms part of the A) buttocks. B) shoulder. C) calf. D) thigh.

calf

Striated involuntary muscle tissue is classified as ________ muscle. A. either smooth or skeletal B. smooth C. skeletal D. cardiac

cardiac

Striated involuntary muscle tissue found in the heart is ________. A. skeletal muscle B. cardiac muscle C. dense regular D. dense irregular E. smooth muscle

cardiac muscle

Muscle tissue found only in the heart

cardiac muscle tissue

The buccinator muscle is in the: A. buttocks. B. cheek. C. chest. D. bladder

cheek

A muscle fiber exposed to a series of stimuli of increasing frequency combines individual twitches (summation) which results in A. flaccid muscles. B. complete sustained contraction. C. muscle tone. D. a latent period.

complete sustained contraction

A tendon is ________, whereas an aponeurosis is ________. A. cordlike and connects muscles to bones; a broad sheet of dense connective tissue that connects muscles to muscles B. a broad sheet of dense connective tissue that connects bones to bones; cordlike and connects muscles to muscles C. cordlike and connects bones to bones; a broad sheet of dense connective tissue that connects muscles to muscles D. a broad sheet of dense connective tissue that connects muscles to muscles; cordlike and connects bones to bones

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

The enzyme acetylcholinesterase causes acetylcholine to A) be secreted from the motor end plate. B) form cross-bridges. C) decompose (broken down into acetic acid and choline to remove it from the synaptic cleft) D) bind to actin.

decompose (broken down into acetic acid and choline to remove it from the synaptic cleft)

The outermost layer of connective tissue surrounding a skeletal muscle is the A. endomysium. B. epimysium. C. perimysium. D. sarcomysium.

epimysium

Muscle fatigue is caused by ________. A. buildup of ATP and lactic acid levels B. exhaustion of energy reserves and buildup of lactic acid levels C. buildup of ATP and pyruvic acid levels D. exhaustion of energy reserves and buildup of pyruvic acid levels

exhaustion of energy reserves and buildup of lactic acid levels

Sandra is playing the piano for her recital. Which muscle is NOT involved in the movement of her hands and/or fingers? A. extensor carpi radialis B. extensor digitorum C. extensor digitorum longus D. flexor carpi radialis E. flexor carpi ulnaris

extensor digitorum longus

The functional unit of muscle contraction is A. the muscle. B. the sarcomere. C. the muscle fiber. D. the myosin cross-bridge.

the sarcomere

Which one of the following is composed mostly of the protein myosin? A. light bands B. Z discs C. thick filaments D. thin filaments E. all myofilaments

thick filaments

Transverse tubules A) store calcium ions. B) connect actin and myosin. C) transmit depolarization impulses into the cell interior around individual myofibrils. D) store sodium ions for the action potential at the cell surface.

transmit depolarization impulses into the cell interior around individual myofibrils.

The triangle of auscultation, commonly used to hear sounds of respiratory organs, is located near the border of the A. pectoralis major and pectoralis minor. B. latissimus dorsi and serratus anterior. C. trapezius and latissimus dorsi. D. pectoralis major and serratus anterior.

trapezius and latissimus dorsi

As a person is vigorously rowing a boat, they suddenly experience extreme pain in their upper arm and no longer complete extension movements at the elbow joint. Which of the following is probably the injured muscle? A) Triceps brachii B) Supinator C) Biceps brachii D) Brachioradialis

triceps brachii

In relaxed muscle, the myosin-binding site on actin is blocked by ________. A. titin B. troponin C. myoglobin D. tropomyosin

tropomyosin