Deck 7: The Muscular System

Question 1

The skeletal muscles store calcium ions in the

A) sarcolemma.
B) sarcomere.
C) sarcosome.
D) sarcoplasmic reticulum.
E) sarcoplasm.

Answer 1

D

Question 2

The center of the sarcomere is the

A) Z line.
B) M line.
C) H band.
D) A band.
E) I band.

Answer 2

B

Question 3

The skeletal muscle organelles that actually contracts is (are) the

A) sarcolemma.
B) sarcomere.
C) transverse tubules.
D) myotubules.
E) myofibrils.

Answer 3

E

Question 4

Which of the following statements describes how muscles help maintain homeostasis?

A) The contractions of skeletal muscles pull on tendons and move elements of the skeleton.
B) Skeletal muscles are responsible for guarding the openings of the digestive and urinary tracts.
C) Skeletal muscles are responsible for the pumping action of the heart.
D) Skeletal muscles support the weight of some internal organs.
E) Skeletal muscle contractions help maintain body temperature.

Question 5

The enzyme acetylcholinesterase causes acetylcholine to

A) decompose.
B) synthesize.
C) bond to actin.
D) be secreted.
E) form cross-bridges.

Question 6

The advantage of having many nuclei in a skeletal muscle fiber is

A) the ability to contract.
B) the ability to produce more ATP with little oxygen.
C) the ability to repair the fiber after an injury.
D) the ability to produce large amounts of the enzymes and structural proteins needed for contraction.
E) none of the above

Question 7

The tropomyosin molecules are attached to

A) actin molecules.
B) myosin molecules.
C) troponin molecules.
D) ATP molecules.
E) calcium ions.

Question 8

Muscle fascicles are separated by

A) endomysium.
B) perimysium.
C) epimysium.
D) sarcolemma.
E) periosteum.

Question 9

The area between Z lines is the

A) sarcolemma.
B) sarcomere.
C) sarcoplasmic reticulum.
D) myofibril.
E) myofilament.

Question 10

Skeletal muscle fibers differ from "typical cells" in that these muscle fibers

A) lack a plasma membrane.
B) have many nuclei.
C) are very small.
D) lack mitochondria.
E) all of the above

Question 11

The area of the sarcomere that contains only thick filaments and no zone of overlap is the

A) Z line.
B) M line.
C) H band.
D) A band.
E) I band.

Question 12

Myofibrils are made primarily of

A) actin and myosin.
B) epimysium.
C) ATP and ADP.
D) troponin.
E) tropomyosin.

Question 13

The ________ contains vesicles filled with acetylcholine.

A) synaptic knob
B) motor end plate
C) neuromuscular junction
D) synaptic cleft
E) transverse tubule

Question 14

The terminal cisternae are parts of the

A) myofilaments.
B) sarcoplasmic reticula.
C) myofibrils.
D) I bands.
E) sarcolemma.

Question 15

The striated appearance of skeletal muscle results from

A) transverse tubule pattern.
B) the sarcoplasmic reticulum.
C) cisternae placement.
D) sarcomere arrangement.
E) all of the above

Question 16

Connective tissue that surrounds an entire muscle is called

A) endomysium.
B) perimysium.
C) sarcolemma.
D) sarcomere.
E) epimysium.

Question 17

At rest, myosin molecules are

A) bound to other myosin molecules.
B) bound to troponin molecules.
C) blocked from binding tropomyosin molecules.
D) bound to ATP molecules.
E) blocked from binding to calcium ions.

Question 18

Which of the following is (are) a function of skeletal muscle?

A) produce movement
B) maintain posture
C) maintain body temperature
D) A and B only
E) all of the above

Question 19

Neurotransmitters that cause skeletal muscle contraction are normally stored in

A) myofibrils.
B) motor neuron endings.
C) motor units.
D) motor end plates.
E) actin.

Question 20

What is the function of the transverse tubule?

A) the storage of calcium ions
B) to transmit muscle impulses to the cell's interior
C) to store sodium ions
D) to allow cross-bridge attachment
E) all of the above

Question 21

Which of the following would have the lowest density of motor units?

A) large muscles of the upper arms
B) postural muscles of the back
C) muscles that control the eye
D) leg muscles
E) the calf muscle

Question 22

Rigor mortis that occurs in skeletal muscles a few hours after death is due to

A) excessive ATP and decreased permeability to calcium.
B) decreased ATP and increased permeability to calcium.
C) excessive ATP.
D) lack of oxygen.
E) lactic acid buildup.

Question 23

The brief moment following stimulation when a muscle is unresponsive to another stimulus is called the ________ period.

A) latent
B) contraction
C) relaxation
D) refractory
E) both C and D

Question 24

Which type of scenario is most likely?

A) Small motor units are recruited first.
B) Large motor units are recruited first.
C) Intermediate-sized motor units are recruited first.
D) All motor units are recruited.
E) The brain chooses motor units randomly.

Question 25

Which of the following muscles would contract most quickly against the same load?

A) a muscle receiving 10 action potentials per second
B) a muscle receiving 20 action potentials per second
C) neither, muscles always contract at the same rate

Question 26

The specialized sarcolemma that contains acetylcholine receptors is the

A) synaptic knob.
B) motor end plate.
C) motor unit.
D) synaptic cleft.
E) I band.

Question 27

Increasing the frequency of stimulation so that a muscle contracts without relaxation is called

A) tetany.
B) a twitch.
C) relaxation.
D) recovery.
E) recruitment.

Question 28

Creatine phosphate serves to

A) cause the decomposition of ATP.
B) supply energy to synthesize ATP.
C) decompose ADP.
D) synthesize ADP.
E) synthesize glucose.

Question 29

Calcium ions are released from the sarcoplasmic reticulum during the ________ phase of contraction.

A) latent
B) contraction
C) twitch
D) relaxation
E) recovery

Question 30

The all-or-none response means that

A) all of the muscles in a region contract together.
B) when a muscle fiber contracts, it contracts completely.
C) all of the muscle fibers within a muscle contract together.
D) when a muscle fiber contracts, all of its ATP is converted to ADP.
E) none of the above

Question 31

Myasthenia gravis is an autoimmune disorder in which antibodies attack acetylcholine receptors. The resulting muscle weakness is likely due to

A) increasing the amount of acetylcholinesterase in the synapse.
B) making the cells less permeable to sodium ions.
C) increasing the amount of potassium ion in the intercellular fluid.
D) making the plasma membranes more permeable to calcium ion.
E) antibodies competing with acetylcholinesterase for acetylcholine.

Question 32

At the neuromuscular junction, the muscle fiber membrane is folded to form a

A) motor end plate.
B) motor unit.
C) neuroreceptor.
D) neurotransmitter.
E) motor neuron.

Question 33

Which of the following is the smaller amount?

A) the concentration of calcium ions in the sarcoplasm of a resting muscle
B) the concentration of calcium ions in the sarcoplasmic reticulum of a resting muscle

Question 34

Contraction during muscle lengthening is called

A) eccentric contraction.
B) concentric contraction.
C) isometric contraction.
D) isotonic contraction.
E) all of the above

Question 35

In response to action potentials arriving from the transverse tubules, the sarcoplasmic reticulum releases

A) acetylcholine.
B) sodium ions.
C) potassium ions.
D) calcium ions.
E) all of the above

Question 36

Rigor mortis occurs at death due to a lack of

A) cAMP.
B) DNA.
C) RNA.
D) ATP.
E) tRNA.

Question 37

When a calcium ion binds to troponin,

A) tropomyosin moves out of the groove between the actin molecules.
B) active sites on the myosin are exposed.
C) actin heads will bind to myosin.
D) muscle relaxation occurs.
E) all of the above

Question 38

In a recording of a muscle twitch, the delay between the stimulus and the muscle response is called the

A) refractory period.
B) latent period.
C) contraction period.
D) relaxation period.
E) both B and D

Question 39

An example of partial but sustained contraction is

A) treppe.
B) tetany.
C) muscle tone.
D) fatigue.
E) a twitch.

Question 40

Which of the following activities would employ isometric contractions?

A) flexing the forearm
B) chewing food
C) standing at attention
D) running
E) writing

Question 41

Which of the following is characteristic of cardiac muscle?

A) Cardiac muscles are striated.
B) Cardiac muscles achieve tetany with every contraction.
C) Cardiac muscle fibers are multinucleated.
D) Cardiac muscles are faster than skeletal muscles.
E) Neurons that innervate cardiac muscles are under voluntary control.

Question 42

Multi-unit smooth muscle

A) is composed of sheets of muscle cells.
B) is found in the wall of the stomach.
C) tends to contract rhythmically.
D) is connected by gap junctions.
E) none of the above

Question 43

Compared to skeletal muscle, smooth muscle

A) contracts faster.
B) relaxes faster.
C) contracts and relaxes faster.
D) contracts faster and relaxes more slowly.
E) contracts and relaxes more slowly.

Question 44

During activities requiring aerobic endurance,

A) glycogen and glycolysis are the primary sources of reserve energy.
B) oxygen debts are common.
C) most of the muscle's energy is produced in mitochondria.
D) fatigue occurs in a few minutes.
E) all of the above

Question 45

Activities that require anaerobic endurance

A) require maximal contraction of muscles for short periods of time.
B) do not use ATP very quickly.
C) usually do not cause an individual to develop an oxygen debt.
D) do not rely on the energy reserves of creatine phosphate.
E) all of the above

Question 46

The term used to describe muscular growth in response to usage is

A) multiple sclerosis.
B) muscular dystrophy.
C) atrophy.
D) hypertrophy.
E) myopathy.

Question 47

When myosin cycling generates less tension than the load,

A) an oxygen debt is repaid.
B) fatigue occurs.
C) relaxation occurs.
D) tetany occurs.
E) atrophy occurs.

Question 48

The amount of oxygen needed to support the conversion of lactic acid to glycogen is called the

A) oxygen debt.
B) refractory amount.
C) anaerobic threshold.
D) aerobic threshold.
E) aerobic conversion.

Question 49

A person whose genetic makeup makes him or her a better marathon runner than a sprinter probably has more ________ in his or her leg muscles.

A) fast fibers
B) intermediate fibers
C) slow fibers
D) dark fibers
E) noncontractile fibers

Question 50

Myoglobin stores

A) oxygen.
B) glycogen.
C) ATP.
D) calcium ions.
E) glucose.

Question 51

Which of the following can be a stimulus for contraction in all three muscle tissue types?

A) epinephrine
B) thyroid hormone
C) testosterone
D) parathyroid hormone
E) acetylcholine

Question 52

Glycolysis

A) refers to the process of anaerobic respiration.
B) can replace ATP in binding to myosin molecules during contraction.
C) acts as the only source of ATP in muscle tissue.
D) is only active during strenuous exercise.
E) can usually make enough ATP for skeletal muscle function.

Question 53

Because skeletal muscle contractions demand large quantities of ATP, skeletal muscles have

A) a rich nerve supply.
B) a rich vascular supply.
C) very few mitochondria.
D) little need for oxygen.
E) all of the above

Question 54

Which of the following is true about red muscles?

A) Red muscles are slower than white muscles.
B) Red muscles have fewer mitochondria than white muscles.
C) Red muscles are dominant in a bodybuilder.
D) Red muscles contain less myoglobin than white muscles.
E) Red muscles fatigue quickly.

Question 55

Fast fibers

A) have high resistance to fatigue.
B) have a high concentration of myoglobin.
C) have many mitochondria.
D) contract quickly.
E) all of the above

Question 56

Increased oxygen consumption would accompany

A) increased heat production.
B) increased conversion of lactic acid to glucose.
C) increased aerobic respiration by muscle cells.
D) increased muscle activity.
E) all of the above

Question 57

Decreasing tension in a muscle due to lowering levels of ATP is called

A) muscle fatigue.
B) the conduction of neural information to the muscle fiber.
C) muscle contraction.
D) muscle relaxation.
E) the striped appearance of skeletal muscle.

Question 58

A muscle cramp is most likely due to lack of

A) ATP.
B) ADP.
C) actin.
D) myosin.
E) acetylcholine.

Question 59

Nonstriated, involuntary muscle is

A) cardiac.
B) red skeletal.
C) smooth.
D) white skeletal.
E) intermediate skeletal.

Question 60

A resting muscle generates most of its ATP by

A) conversion of creatine phosphate.
B) anaerobic respiration.
C) aerobic respiration.
D) the tricarboxylic acid cycle.
E) both C and D

Question 61

The "kissing muscle" that purses the lips is the

A) zygomaticus.
B) orbicularis oris.
C) buccinator.
D) orbicularis oculi.
E) temporalis.

Question 62

Which of the following is the origin of the pectoralis minor?

A) vertebral border near the spine
B) coracoid process of the scapula
C) mastoid region of the skull
D) occipital bone of the skull
E) upper pairs of ribs

Question 63

Which of the following moves the humerus?

A) pectoralis minor
B) deltoid
C) serratus anterior
D) rhomboideus
E) trapezius

Question 64

Which of the following muscles is named for its shape?

A) pectoralis major
B) biceps brachii
C) deltoid
D) erector spinae
E) tibialis anterior

Question 65

Newborns are most likely to develop which muscles most quickly?

A) the masseter and buccinator
B) the buccinator and orbicularis oris
C) the orbicularis oris and risorius
D) the risorius and zygomaticus
E) the levator labii and mentalis

Question 66

Which of the following terms is a descriptive word for a muscle's size?

A) levator
B) extensor
C) tensor
D) longissimus
E) adductor

Question 67

Which of the following describes the action of the trapezius?

A) adducts the arm
B) adducts and flexes the humerus
C) retracts the shoulder and adducts the scapula
D) medial rotation of the humerus
E) lateral rotation of the humerus

Question 68

The transverse processes of the upper cervical vertebrae are the origin of the

A) levator scapulae.
B) rhomboideus major.
C) subclavius.
D) supraspinatus.
E) pectoralis major.

Question 69

Which of the following inserts into fascia, rather than a bone?

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

Question 70

The muscle that inserts on the coronoid process of the mandible is the

A) temporalis.
B) masseter.
C) lateral pterygoid.
D) medial pterygoid.
E) platysma.

Question 71

A muscle that inserts on the radial tuberosity is most likely involved in

A) elbow flexion.
B) elbow extension.
C) protraction.
D) pronation.
E) elbow abduction.

Question 72

The less-movable end of a skeletal muscle is the

A) insertion.
B) belly.
C) origin.
D) proximal end.
E) distal end.

Question 73

Which of the following is a muscle of facial expression?

A) masseter
B) buccinator
C) mentalis
D) temporalis
E) medial and lateral pterygoid

Question 74

Muscles whose names contain the root cervi- would be found in the

A) head.
B) neck.
C) chest.
D) abdomen.
E) groin.

Question 75

Which of the following muscles has its insertion on the cartilage of the ribs?

A) internal oblique
B) external intercostals
C) transversus abdominis
D) internal intercostals
E) both A and B

Question 76

Muscles that insert into the deltoid tuberosity are most likely to

A) flex the shoulder.
B) extend shoulder.
C) abduct the shoulder.
D) adduct the shoulder.
E) none of the above

Question 77

The origin of the frontal belly of the occipitofrontalis muscle is the

A) mandible.
B) frontal bone.
C) occipital bone.
D) galea aponeurotica.
E) temporal bone.

Question 78

Which of the following is considered a postural muscle?

A) erector spinae
B) biceps brachii
C) triceps brachii
D) rectus femoris
E) hamstrings

Question 79

Which of the following is a lateral spinal flexor when used unilaterally?

A) iliocostalis group
B) spinalis group
C) longissimus group
D) quadratus lumborum
E) both A and B

Question 80

The muscle that inserts on the superior surface of the pubis around the symphysis is the

A) internal oblique.
B) external oblique.
C) rectus abdominis.
D) transversus abdominis.
E) diaphragm.