Mastering A&P- chapter 10

Of the various types of skeletal muscle fibers, the ones supplied by the most capillaries are a. slow oxidative fibers. b. fast glycolytic fibers. c. fast oxidative fibers. d. slow glycolytic fibers.

a. slow oxidative fibers.

Both cardiac muscle and this type of muscle are called involuntary. a. skeletal muscle b. smooth muscle

b. smooth muscle

The "cells" of both skeletal muscle and this muscle type are correctly called muscle fibers. a. serous muscle b. smooth muscle c. cardiac muscle

b. smooth muscle

Myofibrils are __________. a. the basic contractile units of skeletal muscle tissue b. specialized contractile organelles found in muscle cells c. the contractile proteins located within a muscle cell d. the boundaries of individual sarcomeres e. None of the listed responses is correct.

b. specialized contractile organelles found in muscle cells

This type of muscle composes the largest share of muscle weight in the human body. a. skeletal muscle b. smooth muscle c. cardiac muscle

a. skeletal muscle

This type of muscle includes the fast oxidative fibers. a. skeletal muscle b. smooth muscle c. cardiac muscle

a. skeletal muscle

This type of muscle may be affected by rhabdomyolysis. a. skeletal muscle b. smooth muscle c. cardiac muscle

a. skeletal muscle

Of the various types of skeletal muscle fibers, the fibers most resistant to fatigue are a. slow oxidative fibers. b. fast glycolytic fibers. c. fast oxidative fibers. d. slow glycolytic fibers.

a. slow oxidative fibers.

Of the various types of skeletal muscle fibers, the ones with the thinnest myofibrils are a. slow oxidative fibers. b. fast glycolytic fibers. c. fast oxidative fibers. d. slow glycolytic fibers.

a. slow oxidative fibers.

Of the various types of skeletal muscle fibers, the type with the most mitochondria is a. slow oxidative fibers. b. fast glycolytic fibers. c. fast oxidative fibers. d. slow glycolytic fibers.

a. slow oxidative fibers.

Sarcopenia is a. the loss of muscle mass with age. b. a decrease in the amount of actin in the muscle fiber. c. a decrease in the amount of sarcolemma in the muscle fiber. d. a decrease in the muscle's need for energy.

a. the loss of muscle mass with age.

Acetylcholinesterase breaks down acetylcholine to prevent additional __________.

twitches

T/F: The repeating segments seen in a skeletal muscle fiber are the T tubules.

false

T/F: Muscular dystrophy is a sex-linked, dominant gene that primarily affects females.

false

During eccentric contraction, muscles resist gravity, acting like a__________.

brake

This type of muscle is found in the heart. a. skeletal muscle b. smooth muscle c. cardiac muscle

c. cardiac muscle

Age-related loss of muscle mass may be influenced by all of these except: a. degeneration of muscle fibers because of accumulation of calcium in the sarcoplasm. b. an increase in the relative proportion of connective tissue to number of muscle fibers. c. decrease in the level of testosterone. d. exhaustion of the supply of muscle satellite cells.

c. decrease in the level of testosterone.

The embryonic origin of muscle tissue is from a. endoderm. b. ectoderm. c. mesoderm. d. epidermis.

c. mesoderm.

The point at which a nerve ending and skeletal fiber meet is called a(n) ______. a. axon terminal b. axon c. neuromuscular junction d. synaptic cleft

c. neuromuscular junction

Which of the following is a similarity among skeletal, cardiac, and smooth muscles? a. Their plasma membranes are called endomysium. b. Their tissues are not under voluntary control. c. The cells of all three are striated. d. Their tissues contract as a sheet. e. All three depend on myofilaments for contraction.

e. All three depend on myofilaments for contraction.

T/F: During contraction, the A band of a sarcomere shortens.

false

T/F: Skeletal muscles never undergo mitosis after they are fully formed.

true

T/F: Contraction of a muscle cell requires the influx of calcium into the sarcoplasm.

true

T/F: Delayed-onset muscle soreness is caused by inflammation that results from microscopic tears in muscle fibers following exceptionally strenuous muscle activity.

true

T/F: Fascicles are bundles of muscle fibers wrapped together within perimysium.

true

T/F: Skeletal muscle fibers are multinucleate, because they arose from a number of embryonic cells.

true

T/F: The Z disks, sometimes referred to as Z lines, define each sarcomere at both ends.

true

This type of muscle attaches to bone, but may also attach to skin, cartilage, fascia or a raphe. a. skeletal muscle b. smooth muscle c. cardiac muscle

a. skeletal muscle

In skeletal muscle fibers, which band or zone contains both thick and thin myofilaments? a. A b. I c. Z d. H

a. A

Which region of the sarcomere does not change in length during contraction? a. A band b. H zone c. Z disk to Z disk d. I band

a. A band

Contractions of these muscles are under voluntary control. a. skeletal muscle b. smooth muscle c. cardiac muscle

a. skeletal muscle

The area that contains no thin filaments is known as the a. H zone. b. I band. c. intercalated disc. d. A band.

a. H zone.

What is the result of skeletal muscles being formed from the fusion of embryonic myoblasts? a. Skeletal muscle fibers are multinucleate. b. Skeletal muscles are striated. c. Skeletal muscles are contractile organs. d. Satellite cells surrounding muscle cells cause proliferation of myofibrils as energy requirements of skeletal muscles increase. e. All of the listed responses are correct.

a. Skeletal muscle fibers are multinucleate.

Define a motor unit. a. a single motor neuron and all muscle fibers it innervates b. the nerve fibers that innervate skeletal muscle c. a neuromuscular junction d. a group of muscle fibers within a single fascicle that contract together

a. a single motor neuron and all muscle fibers it innervates

A flat sheet of connective tissue that extends beyond the muscle fibers to attach the muscle to bone is a(n) ______. a. aponeurosis b. raphe c. tendon d. fascicle

a. aponeurosis

Myofascial pain syndrome is ______. a. associated with overused or strained postural muscles b. uncommon in anyone under 60 years of age c. treated with antidepressants and pain relievers d. hereditary, affecting males almost exclusively

a. associated with overused or strained postural muscles

Acetylcholine a. binds to the sarcolemma and initiates an impulse in the muscle fiber. b. binds to the myosin head, enabling it to form cross-bridges with actin. c. breaks down the neurotransmitter that activates muscle fibers. d. is released from the sarcoplasmic reticulum and binds to actin.

a. binds to the sarcolemma and initiates an impulse in the muscle fiber.

The sarcoplasmic reticulum (SR) stores a. calcium. b. ATPase. c. sodium. d. myosin.

a. calcium.

An aponeurosis a. connects a muscle to underlying structures through a flat sheet or web. b. is a type of direct attachment of muscle to bone. c. consists of a neuron and all the muscle fibers it innervates. d. is the junction between the axon terminus of a neuron to an individual muscle fiber.

a. connects a muscle to underlying structures through a flat sheet or web.

Which protein strengthens the sarcolemma by connecting the cytoskeleton with the extracellular matrix? a. dystrophin b. titin c. actin d. myosin

a. dystrophin

The property of skeletal muscle function that allows recoil after being stretched is ______. a. elasticity b. contractility c. excitability d. extensibility

a. elasticity

Slow oxidative fibers __________. a. have thin fibers, numerous mitochondria, and abundant myoglobin b. are intermediate in many respects, more powerful than some types of fibers, and use aerobic pathways c. use anaerobic pathways to make adenosine triphosphate (ATP), tire quickly, and are very powerful d. are common in muscles of the legs that are specifically designed for powerful, movements

a. have thin fibers, numerous mitochondria, and abundant myoglobin

Myofascial pain syndrome is best described as a condition in which a. muscle fibers contract when the skin superficial to them is stroked. b. pain occurs in at least 11 of 18 standardized points across the body. c. muscle fibers degenerate because of chronic leakage of extracellular calcium. d. microscopic tears in muscle fibers result in swelling and inflammation.

a. muscle fibers contract when the skin superficial to them is stroked.

This type of muscle makes up the walls of hollow organs, such as the stomach and uterus. a. skeletal muscle b. smooth muscle c. cardiac muscle

b. smooth muscle

This type of muscle, along with cardiac muscle, is called visceral muscle. a. skeletal muscle b. smooth muscle c. cardiac muscle

b. smooth muscle

Which of these is not in direct contact with thick myofilaments? a. ATPase b. synaptic vesicles c. actin d. myosin

b. synaptic vesicles

The region of thin filaments only that is part of two adjacent sarcomeres is the __________. a. A band b. I band c. M line d. H zone e. Z disc

b. I band

Of the various types of skeletal muscle fibers, the type that produces the most power is a. slow oxidative fibers. b. fast glycolytic fibers. c. fast oxidative fibers. d. slow glycolytic fibers.

b. fast glycolytic fibers.

This type of muscle is found in large vessels leading to and from the heart. a. skeletal muscle b. smooth muscle c. cardiac muscle

b. smooth muscle

The type of attachment in which the muscle fibers seem to attach directly to a bone is a. an insertion. b. a fleshy attachment. c. a tendon. d. an aponeurosis.

b. a fleshy attachment.

Sarcopenia is __________. a. severe pain resulting from disorders of muscle tissue b. a loss of muscle mass and decrease in muscle strength that may occur with advancing age c. a sudden, involuntary twitch of skeletal muscle due to chemical imbalances or injury d. a quickly metastasizing type of cancer that affects muscle tissue e. a series of spasms of the eyelid or facial muscles resulting from stress and other psychological factors.

b. a loss of muscle mass and decrease in muscle strength that may occur with advancing age

One of the largest and strongest muscles in the body is the gluteus maximus in the buttocks, which is important in these diverse muscular activities; walking, running, and climbing stairs. It must consist of a. fast glycolytic fibers only. b. a mixture of fiber types. c. fast oxidative fibers only. d. slow oxidative fibers only.

b. a mixture of fiber types.

An aponeurosis is a. a nerve to a muscle. b. a sheet of dense connective tissue. c. a large muscle. d. clinical pain in a muscle.

b. a sheet of dense connective tissue.

Sarcoplasmic reticulum lies a. between muscles but in myofilaments. b. between myofibrils but in fibers. c. between fascicles but outside fibers. d. between fibers but in myofilaments.

b. between myofibrils but in fibers.

The only muscle cells that branch are ________ muscle cells. a. smooth b. cardiac c. red d. skeletal

b. cardiac

The ability of the sarcolemma of muscle cells to conduct an impulse is an example of a. contractility. b. excitability. c. elasticity. d. extensibility.

b. excitability.

With intense resistance training, a. slow oxidative fibers can convert to fast oxidative fibers. b. fast glycolytic fibers can convert to fast oxidative fibers. c. fast oxidative fibers can convert to fast glycolytic fibers. d. slow oxidative fibers can convert to fast glycolytic fibers.

b. fast glycolytic fibers can convert to fast oxidative fibers.

Of the various types of skeletal muscle fibers, the fibers that experience fatigue sooner are a. slow oxidative fibers. b. fast glycolytic fibers. c. fast oxidative fibers. d. slow glycolytic fibers.

b. fast glycolytic fibers.

Of the various types of skeletal muscle fibers, the type containing the most glycogen granules is a. slow oxidative fibers. b. fast glycolytic fibers. c. fast oxidative fibers. d. slow glycolytic fibers.

b. fast glycolytic fibers.

Fast glycolytic muscle fibers __________. a. have fewer,smaller myofilaments b. generate lots of power and depend on anaerobic pathways to make adenosine triphosphate (ATP) c. are prevalent in postural muscles of the back d. are abundant in muscles of the lower limbs, contract quickly, and are oxygen-dependent e. have abundant myoglobin and numerous mitochondria

b. generate lots of power and depend on anaerobic pathways to make adenosine triphosphate (ATP)

After a muscle fiber has contracted, the calcium a. is chemically bound to the myofilaments. b. is actively transported into the sarcoplasmic reticulum. c. is destroyed. d. is secreted by the Golgi apparatus.

b. is actively transported into the sarcoplasmic reticulum.

In muscular dystrophy, a. most cases appear in young females. b. muscle fibers degenerate and atrophy. c. most forms of the disease do not appear to be inherited. d. muscles decrease in size because of loss of fat and connective tissue.

b. muscle fibers degenerate and atrophy.

Z discs (Z lines) are ______. a. the attachment sites for thick filaments b. the boundaries of two adjacent sarcomeres c. the elaborate smooth endoplasmic reticulum surrounding a myofibril d. invaginations of the sarcolemma of a skeletal muscle fiber

b. the boundaries of two adjacent sarcomeres

If you could not see the H zone in a photomicrograph of a sarcomere in skeletal muscle, ______. a. you are looking at slow oxidative fibers b. the sarcomere is fully contracted c. titin, the springlike molecule has become paralyzed due to lack of ATP d. the person from whom the sample was taken has muscular dystrophy

b. the sarcomere is fully contracted

In striated muscle, the I band is where a. only thick filaments occur. b. thin filaments occur. c. H zones occur. d. thick and thin filaments occur.

b. thin filaments occur.

Myoglobin a. is released by the sarcoplasmic reticulum. b. is found within the T tubules. c. binds and stores oxygen for ATP production. d. provides energy for contraction.

c. binds and stores oxygen for ATP production.

A cell of this type of muscle is striated and can be uninucleated or binucleated. a. skeletal muscle b. smooth muscle c. cardiac muscle

c. cardiac muscle

Both single-unit smooth muscle and this type of muscle have gap junctions. a. skeletal muscle b. smooth muscle c. cardiac muscle

c. cardiac muscle

What is the importance of acetylcholinesterase in the neuromuscular junction? a. It breaks down acetylcholine so that particular muscle fiber will not be stimulated again. b. It ensures that multiple twitches are produced from a single stimulation. c. It breaks down acetylcholine immediately after the neurotransmitter signals a contraction. d. It prevents stimulation of muscle fibers.

c. It breaks down acetylcholine immediately after the neurotransmitter signals a contraction.

This type of muscle contains intercalated discs. a. skeletal muscle b. smooth muscle c. cardiac muscle

c. cardiac muscle

Which mechanism describes the formation of multinucleated skeletal muscle fibers? a. The nucleus of a muscle fiber undergoes repeated mitosis, but not cytokinesis; therefore, the fiber develops multiple nuclei. b. Adjacent muscle fibers fuse during childhood to produce thick, multinucleated muscle fibers in adults. c. Multiple myoblasts fuse into a single muscle fiber during embryonic development. d. Muscle fibers undergo repeated mitosis, especially during adolescence when muscles grow at an accelerated rate.

c. Multiple myoblasts fuse into a single muscle fiber during embryonic development.

The notation "A" in A band is for __________. a. ATPase enzyme b. attachment c. anisotropic d. acetylcholine

c. anisotropic

Identify the structure within the muscle fiber that carries an electrical impulse from the surface membrane deep into the muscle fiber. a. terminal cisterna b. sarcoplasmic reticulum c. T tubule d. Z disc

c. T tubule

Which of the following correctly defines a triad of the sarcomere? a. actin, troponin, and tropomyosin b. actin, myosin, and titin c. a T tubule and two adjacent terminal cisterns d. an axon terminal, synaptic cleft, and sarcolemma

c. a T tubule and two adjacent terminal cisterns

A muscle fascicle is a. a bundle of myofilaments. b. a tendon. c. a bundle of cells. d. a single muscle cell.

c. a bundle of cells.

Excitability is the special functional feature of muscle tissue that __________. a. gives muscle tissue the property of passive recoil after being stretched b. gives muscles their ability to shorten and generate pulling force c. allows electrical impulses to travel along the cells' sarcolemma, leading to contraction d. gives muscle tissue the ability to stretch by the contraction of an opposing muscle e. All of the listed responses are correct.

c. allows electrical impulses to travel along the cells' sarcolemma, leading to contraction

A common characteristic of the three types of muscle tissue is that a. they can all use aerobic and anaerobic methods to utilize energy. b. they all have striations. c. contraction is triggered by the release of calcium. d. they all contain sarcomeres.

c. contraction is triggered by the release of calcium.

Delayed-onset muscle soreness is caused by a. accumulation of lactic acid. b. overnight cramps that occur after strenuous exercise. c. microscopic tears and resulting inflammation. d. depletion of ATP during prolonged activity.

c. microscopic tears and resulting inflammation.

As skeletal muscles enlarge in a weight lifter, all of the following occur except a. muscle cells grow larger. b. myofilaments become more abundant in the muscle cells. c. muscle cells divide mitotically. d. myofibrils become more abundant in the muscle cells.

c. muscle cells divide mitotically.

Titin a. connects myosin to actin. b. forms the Z disk to which actin attaches. c. prevents a muscle from being overstretched. d. limits the degree to which a muscle may contract.

c. prevents a muscle from being overstretched.

Of the three classes of muscle cells, the only one in which the nuclei lie peripherally instead of centrally is a. cardiac. b. smooth. c. skeletal. d. visceral.

c. skeletal.

Which of the following statements is NOT an important function of the connective tissue sheaths contained within skeletal muscle? a. transmit contractile forces from the muscle fibers to the skeletal system b. provide a passageway for blood vessels and nerves c. storage of fat for a ready energy source for active muscles d. bind muscle fibers together and contribute to elasticity of muscle

c. storage of fat for a ready energy source for active muscles

-Exhibits inherent rhythmicity -Connected by intercalated discs -Gap junctions needed for coordinated contractions

cardiac muscle

Myofilaments __________. a. include actin and myosin b. are specific types of microfilaments c. are responsible for shortening muscle cells d. All of the listed responses are correct.

d. All of the listed responses are correct.

Why are there fewer muscle fibers per motor unit in the fingers than in the muscles of the thighs? a. The thighs need more muscle fibers per motor unit to execute motions such as walking. b. The fingers are smaller than the thighs. c. Thighs need finer control of movement than do the fingers. d. Fewer muscle fibers per motor unit allows for fine control of muscle action.

d. Fewer muscle fibers per motor unit allows for fine control of muscle action.

What is the primary reason that men have greater muscle mass than women? a. Men are larger than women, so their percent muscle mass is greater. b. Men take more anabolic steroids than women. c. Men are less affected by aging than women. d. The effects of androgen hormones give men greater muscle mass than women.

d. The effects of androgen hormones give men greater muscle mass than women.

During contraction, which of the following occurs in a sarcomere? a. The A band gets longer. b. Thick filaments slide across each other to make titin more "springy." c. Z discs move farther apart. d. The lengths of the I bands and the H zone decrease. e. The thick and thin filaments get shorter.

d. The lengths of the I bands and the H zone decrease.

Which statement about muscle attachments is false? a. At least one joint is present between an origin and insertion. b. Insertions are usually distal to the origin. c. An insertion can be at either attachment point of a muscle, depending on body position and the movement being performed. d. Upon contraction, the origin is pulled toward the insertion.

d. Upon contraction, the origin is pulled toward the insertion.

What causes a strain or muscle pull? a. a tear in a tendon b. pain in a muscle due to any muscle disorder c. a sudden involuntary spasm of a muscle d. a tear in a muscle

d. a tear in a muscle

Endomysium, perimysium, and epimysium __________. a. are the points of origin of a muscle b. are the plasma membranes around muscle fibers c. provide nutrients and oxygen to skeletal muscles d. are each continuous with tendons, so they can work together to produce force e. transmit the force of contraction to the belly of the contracting muscle

d. are each continuous with tendons, so they can work together to produce force

In limbs, the insertions of muscles almost always lie ________ to their origins. a. proximal b. posterior c. lateral d. distal

d. distal

Which type of muscle fiber has no myofibrils? a. skeletal b. cardiac c. red d. smooth

d. smooth

In a sarcomere, the thin filaments are __________. a. the central part of an A band b. the portion of a sarcomere that creates the dark-staining portions of the striations c. the region made of myosin filaments d. the region where calcium ions bind e. composed of slow oxidative fibers

d. the region where calcium ions bind

In striated muscle cells, which of these structures stores calcium ions that trigger contraction? a. the myofibrils b. the internal surface of the plasma membrane c. T tubules d. the terminal cisterns

d. the terminal cisterns

How does the sliding filament mechanism result in concentric contraction of skeletal muscle? a. Thin filaments attach to the myosin heads of thick filaments at the middle of a sarcomere and pull the thick filaments toward the center of the sarcomere. b. Norepinephrine diffuses out of vesicles at axon terminals and causes the concentric contraction to occur. c. Titin, a spring-like molecule that extends the length of the thick filaments, pulls the myofibrils toward the center of a sarcomere. d. Acetylcholine diffuses out of vesicles at axon terminals and causes the concentric contraction to occur. e. Myosin heads of thick filaments attach to thin filaments at both ends of a sarcomere and pull the thin filaments toward the center of the sarcomere.

e. Myosin heads of thick filaments attach to thin filaments at both ends of a sarcomere and pull the thin filaments toward the center of the sarcomere.

During contraction of a sarcomere, what happens to the A band? a. It shortens, because the myosin myofibrils (thick filaments) shorten. b. The pull of actin filaments causes it to lengthen. c. The A bands overlap, due to the pull of the thin filaments on the thick filaments. d. It disappears. e. None of the listed responses is correct.

e. None of the listed responses is correct.

Rhabdomyolysis is __________. a. a mysterious chronic pain syndrome of unknown cause that results in fatigue. b. an inherited sex-linked recessive disorder of muscle weakness leading to death c. a common pain syndrome caused by tightened bands of muscle fiber d. a common condition of muscle soreness after exercise e. a condition in which myoglobin pours from crushed muscle tissue into the bloodstream, causing renal failure

e. a condition in which myoglobin pours from crushed muscle tissue into the bloodstream, causing renal failure

One motor neuron and all the muscle fibers it innervates is __________. a. a T tubule b. a synaptic cleft c. an axon terminal d. the sarcoplasmic reticulum e. a motor unit

e. a motor unit

T/F: Fibromyalgia is a muscular disease, and its cause is known to be genetic.

false

-Arranged into fascicles -Under voluntary control -Always multinucleated

skeletal muscle

-Has greatest capacity to regenerate -Lacks sarcomeres -Typically arranged into circular and longitudinal layers

smooth muscle