Deck 6: The Muscular System

Question 1

Using Figure 6.2, match the following:
The epimysium is represented by ________.

A) Label A
B) Label B
C) Label C
D) Label D

Answer 1

A

Question 2

Muscle tissue has the ability to shorten when adequately stimulated, a characteristic known as ________.

A) elasticity
B) irritability
C) contractility
D) extensibility

Answer 2

C

Question 3

The heads of the myosin myofilaments are called ________ when they link the thick and thin filaments together during skeletal muscle contraction.

A) neuromuscular junctions
B) synapses
C) cross bridges
D) motor units

Answer 3

C

Question 4

Using Figure 6.1, match the following:
The A band within a myofibril is indicated by ________.

A) Label A
B) Label B
C) Label C
D) Label D

Question 5

What organelle wraps and surrounds the myofibril and stores calcium?

A) cross bridge
B) sarcomere
C) sarcolemma
D) sarcoplasmic reticulum

Question 6

Which term does NOT describe smooth muscle cells?

A) visceral
B) nonstriated
C) skeletal
D) involuntary

Question 7

A smooth, sustained contraction, with no evidence of relaxation, is called ________.

A) fused, or complete, tetanus
B) a twitch
C) unfused, or incomplete, tetanus
D) summing of contractions

Question 8

What is the unstoppable electrical current that travels down the length of the entire surface of a sarcolemma?

A) neuromuscular junction
B) action potential
C) neurotransmitter
D) acetylcholine

Question 9

Contractions in which muscles shorten and produce movement are known as ________.

A) isotonic contractions
B) twitches
C) isometric contractions
D) resistance exercises

Question 10

Using Figure 6.1, match the following:
The H zone, located within the A band, lacks thin filaments and is represented by ________.

A) Label A
B) Label B
C) Label C
D) Label D

Question 11

The point of muscle attachment to an immovable or less movable bone is known as the ________.

A) innervation
B) action
C) insertion
D) origin

Question 12

According to the sliding filament theory, how does muscle contraction occur?

A) Myosin heads form cross bridges and pull thin filaments, causing them to slide.
B) Both thick and thin filaments shorten as the muscle contracts.
C) A bands bunch up and shorten as myosin heads attach to thin filaments.
D) Myosin heads attach and detach from thin filaments, causing thin filaments to shorten.

Question 13

Striated involuntary muscle tissue is classified as ________ muscle.

A) skeletal
B) cardiac
C) smooth
D) either smooth or skeletal

Question 14

One neuron and all the skeletal muscles it stimulates is known as a ________.

A) sarcoplasmic reticulum
B) motor unit
C) synaptic cleft
D) neuromuscular junction

Question 15

Using Figure 6.2, match the following:
The muscle fiber (cell) is indicated by ________.

A) Label A
B) Label B
C) Label C
D) Label D

Question 16

Anaerobic glycolysis requires ________ to make ATP.

A) creatine phosphate only
B) oxygen only
C) glucose only
D) both oxygen and glucose

Question 17

Using Figure 6.1, match the following:
The myofilament composed of actin is indicated by ________.

A) Label A
B) Label B
C) Label C
D) Label D

Question 18

Using Figure 6.2, match the following:
The perimysium wraps a fascicle of muscle cells and is represented by ________.

A) Label A
B) Label B
C) Label C
D) Label D

Question 19

Using Figure 6.1, match the following:
The I band within a skeletal muscle fiber is indicated by ________.

A) Label A
B) Label B
C) Label C
D) Label D

Question 20

Using Figure 6.2, match the following:
The endomysium that wraps individual muscle fibers is indicated by ________.

A) Label A
B) Label B
C) Label C
D) Label D

Question 21

A motor neuron and all of the skeletal muscle fibers it stimulates are termed a ________.

A) myofilament
B) synaptic cleft
C) motor unit
D) neuromuscular junction
E) neurotransmitter

Question 22

The type of muscle tissue pictured in Figure 6.3 is ________.

A) skeletal muscle
B) voluntary
C) striated
D) found only in the heart
E) smooth muscle

Question 23

Which facial muscle is considered the "smiling" muscle since it raises the corners of the mouth?

A) orbicularis oris
B) frontalis
C) orbicularis oculi
D) zygomaticus

Question 24

The arrangement of fascicles in orbicularis oris is ________.

A) circular
B) convergent
C) pennate
D) fusiform

Question 25

What is covered by the endomysium?

A) fascicles of muscle cells
B) an entire muscle
C) an individual muscle cell
D) myofibrils
E) smooth muscle only

Question 26

Which one of the following is composed mostly of the protein myosin?

A) thick filaments
B) thin filaments
C) all myofilaments
D) Z discs
E) light bands

Question 27

Striated involuntary muscle tissue found in the heart is ________.

A) smooth muscle
B) skeletal muscle
C) dense regular
D) cardiac muscle
E) dense irregular

Question 28

Jason injured his hamstring muscle group during football practice. He will be unable to perform ________.

A) thigh extension and knee flexion
B) dorsiflexion
C) thigh abduction and adduction
D) leg rotation and plantar flexion

Question 29

Muscles that perform opposite actions to one another are termed ________.

A) synergists
B) prime movers
C) antagonists
D) fixators

Question 30

The plasma membrane of a skeletal muscle cell is called the ________.

A) sarcolemma
B) sarcomere
C) myofilament
D) sarcoplasm
E) sarcoplasmic reticulum

Question 31

An inherited disease that causes muscles to degenerate and atrophy is known as ________.

A) torticollis
B) muscular dystrophy
C) cystic fibrosis
D) myasthenia gravis

Question 32

Which type of muscle tissue contracts most quickly upon stimulation?

A) skeletal
B) visceral
C) cardiac
D) smooth
E) tendons

Question 33

What is acetylcholine?

A) an ion pump on the postsynaptic membrane
B) a source of energy for muscle contraction
C) a component of thick myofilaments
D) an oxygen-binding protein
E) a neurotransmitter that stimulates skeletal muscle to contract

Question 34

What is released by axon terminals into the synaptic cleft to stimulate a muscle to contract?

A) potassium ions
B) actin
C) sodium ions
D) acetylcholine
E) myosin heads

Question 35

The mechanical force of contraction is generated by ________.

A) shortening of the thick filaments
B) shortening of the thin filaments
C) a sliding of thin filaments past thick filaments
D) the "accordion-like" folding of thin and thick filaments
E) the temporary disappearance of thin filaments

Question 36

What creates the alternating light and dark bands that provides the striation pattern on skeletal muscle tissue?

A) sarcoplasm and sarcolemma
B) thick filaments and myosin heads
C) A bands and I bands
D) H zones and M lines
E) Z discs and H zones

Question 37

Why are calcium ions necessary for skeletal muscle contraction?

A) Calcium ions increase the speed of the action potential transmitted along the sarcolemma.
B) Calcium ions release the inhibition on Z discs.
C) Calcium ions trigger the binding of myosin heads to actin filaments.
D) Calcium ions cause ATP binding to actin.
E) Calcium ions bind to regulatory proteins on the myosin filaments, changing both their shape and their position on the thick filaments.

Question 38

Which of the following is NOT a function of the muscular system?

A) production of movement
B) maintenance of posture
C) stabilization of joints
D) generation of heat
E) blood cell formation

Question 39

The prime mover of arm abduction is the ________ muscle.

A) trapezius
B) deltoid
C) triceps brachii
D) biceps brachii

Question 40

A sarcomere is ________.

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

Question 41

A skeletal muscle twitch differs from a tetanic contraction in that ________.

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

Question 42

Which of the following is a type isometric exercise in which muscles increase in size and strength?

A) swimming
B) biking
C) jogging
D) lifting weights
E) dancing

Question 43

Which of these events must occur first to trigger the skeletal muscle to generate an action potential and contract?

A) Sodium ions rush into the cell.
B) Acetylcholine (ACh) binds to receptors on the sarcolemma and allows passage of sodium ions into the cell.
C) Potassium ions diffuse out of the muscle cell.
D) The sodium-potassium pump restores sodium and potassium back to their initial positions.
E) Acetylcholinesterase (AchE) breaks down acetylcholine (ACh).

Question 44

Which of the following is an example of an isometric contraction?

A) shaking the head as to say "no"
B) pushing against an immovable wall
C) bending the elbow
D) rotating the arm
E) nodding the head as to say "yes"

Question 45

Which muscle helps compress the abdominal contents during defecation or childbirth?

A) internal intercostals
B) deltoids
C) trapezius
D) iliopsoas
E) rectus abdominis

Question 46

Which of these muscles is the prime mover of elbow extension?

A) brachialis
B) latissimus dorsi
C) deltoid
D) triceps brachii
E) biceps brachii

Question 47

Which movement is opposite to abduction?

A) flexion
B) rotation
C) circumduction
D) adduction
E) supination

Question 48

Sandra is playing the piano for her recital. Which muscle is NOT involved in the movement of her hands and/or fingers?

A) flexor carpi radialis
B) flexor carpi ulnaris
C) extensor digitorum
D) extensor digitorum longus
E) extensor carpi radialis

Question 49

What must rush into a muscle cell to promote its depolarization?

A) potassium ions
B) calcium ions
C) acetylcholine
D) sodium ions
E) acetylcholinesterase

Question 50

A nursing infant develops a powerful sucking muscle that adults also use for whistling or blowing a trumpet called the ________.

A) platysma
B) masseter
C) zygomaticus
D) buccinator
E) temporalis

Question 51

Which of these muscles is located on the ventral (anterior) side of the body?

A) pectoralis major
B) occipitalis
C) gastrocnemius
D) gluteus medius
E) latissimus dorsi

Question 52

The condition of skeletal muscle fatigue can be best explained by ________.

A) the all-or-none law
B) the inability to generate sufficient quantities of ATP due to feedback regulation of synthesis
C) the inability of the muscle to contract even if it is being stimulated
D) a total lack of ATP in the body
E) inadequate numbers of mitochondria in muscle cells

Question 53

Which method of regenerating ATP during muscle contraction can produce lactic acid?

A) aerobic cellular respiration
B) oxidative phosphorylation
C) direct phosphorylation
D) creatine phosphate
E) anaerobic glycolysis

Question 54

The gap between the axon terminal of a motor neuron and the sarcolemma of a skeletal muscle cell is called the ________.

A) motor unit
B) sarcomere
C) neuromuscular junction
D) synaptic cleft
E) cross bridge

Question 55

During skeletal muscle contraction, to what do myosin heads bind?

A) myosin filaments
B) actin filaments
C) Z discs
D) thick filaments
E) the H zone

Question 56

Neurotransmitters are released upon stimulation from a nerve impulse from the ________.

A) myofibrils
B) sarcoplasmic reticulum
C) thick filaments
D) axon terminals of the motor neuron
E) sarcolemma of the muscle cell

Question 57

What enzyme breaks down acetylcholine into acetic acid and choline to prevent continued contraction of the muscle fiber?

A) potassium ions
B) cross bridges
C) calcium ions
D) sarcoplasmic reticulum
E) acetylcholinesterase

Question 58

Creatine phosphate (CP) functions within the muscle cells by ________.

A) forming a temporary chemical compound with myosin
B) forming a chemical compound with actin
C) inducing a conformational change in the myofilaments
D) storing energy that will be transferred to ADP to resynthesize ATP as needed
E) storing energy that will be transferred to ATP to resynthesize ADP as needed

Question 59

Which of the following muscles acts as a synergist to masseter and closes the jaw?

A) buccinator
B) zygomaticus
C) frontalis
D) sternocleidomastoid
E) temporalis

Question 60

Skeletal muscle, as a whole, can generate different amounts of force, and different degrees of shortening, in response to stimuli. What is this concept called?

A) graded response
B) twitch
C) fused, or complete, tetanus
D) incomplete, or unfused, tetanus
E) action potential

Question 61

The formation of cross bridges requires both calcium ions and ATP.

Question 62

A neuromuscular junction consists of one neuron and all the skeletal muscles it stimulates.

Question 63

Which of the following muscles are antagonists?

A) biceps brachii and triceps brachii
B) biceps femoris and biceps brachii
C) vastus medialis and vastus lateralis
D) masseter and temporalis
E) gastrocnemius and soleus

Question 64

Which of the following consists of two large, flat muscles that cover the lower back?

A) deltoid
B) biceps brachii
C) triceps brachii
D) latissimus dorsi
E) pectoralis major

Question 65

What is the main function of the quadriceps group?

A) arm flexion
B) hand supination
C) thigh abduction
D) knee extension
E) foot inversion

Question 66

Depolarization of a skeletal muscle cell leads to the opening of more channels that only allow potassium entry.

Question 67

Which one of the following is NOT a criterion generally used in naming muscles?

A) relative size of the muscle
B) number of origins of the muscle
C) shape of the muscle
D) method of attachment of the muscle to bone
E) action of the muscle

Question 68

The striations seen in skeletal muscle are actually alternating dark A and light I bands.

Question 69

Cardiac and skeletal muscle both possess striations.

Question 70

Paralysis of which of the following would make an individual unable to flex the hip?

A) biceps femoris
B) gastrocnemius
C) tibialis anterior
D) soleus
E) iliopsoas

Question 71

Cardiac muscle fibers are joined by special gap junctions called intercalated discs; these discs allow heart activity to be closely coordinated.

Question 72

Smooth muscles stabilize joints of the skeleton.

Question 73

What condition results if muscles are not used, such as when immobilized in a cast for healing a broken bone?

A) hypertrophy
B) lordosis
C) atrophy
D) spina bifida
E) scoliosis

Question 74

Which muscle forms the curved calf of the posterior leg?

A) fibularis longus
B) gastrocnemius
C) rectus femoris
D) tibialis anterior
E) soleus

Question 75

Like the biceps brachii muscle, which muscle is a prime mover in elbow flexion?

A) triceps brachii
B) deltoid
C) brachioradialis
D) fibularis longus
E) brachialis

Question 76

The sarcoplasmic reticulum wraps like a sleeve around the myofibril and stores and releases calcium.

Question 77

Which muscle group adducts the thighs?

A) gluteus muscles
B) adductor group
C) hamstring group
D) quadriceps group
E) fibularis muscles

Question 78

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) extension
B) flexion
C) abduction
D) adduction
E) circumduction

Question 79

Which muscle group includes the biceps femoris, semimembranosus, and semitendinosus?

A) abdominal muscles
B) quadriceps group
C) adductor group
D) fibularis muscles
E) hamstring group

Question 80

The neurotransmitter used by the nervous system to activate skeletal muscle cells is acetylcholine.