Ch 10 Muscle Tissue

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.

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

a. smooth

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

b. skeletal

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

b. smooth

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

b. smooth muscle

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

a tear in a muscle

Both cardiac muscle and this type of muscle are called involuntary.

smooth

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

a. skeletal muscle

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

False

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

False

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

False

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

False

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 contractile organs. c. Satellite cells surrounding muscle cells cause proliferation of myofibrils as energy requirements of skeletal muscles increase. d. Skeletal muscles are striated. e. All of the listed responses are correct.

A. Skeletal muscle fibers are multinucleated.

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

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

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- Skeletal muscles never undergo mitosis after they are fully formed.

True

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

True

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

True

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

a. A

Excitation of the sarcolemma is coupled or linked to the contraction of a skeletal muscle fiber. What specific event initiates the contraction? a. Calcium release from the sarcoplasmic reticulum initiates the contraction. b. Action potentials propagate into the interior of the skeletal muscle fiber. c. Voltage-sensitive proteins change shape. d. Sodium release from the sarcoplasmic reticulum initiates the contraction.

a. Calcium release from the sarcoplasmic reticulum initiates the contraction.

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

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

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

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

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

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

After three months of training, during which he was able to lift increasingly heavier weights, Abe's arm and chest muscles became much larger. What happened to the fibers in these muscles? a. Weight lifting stimulated the production of more proteins and consequently an increase in sarcomeres and myofibrils within each cell. b. Weightlifting increased the number of motor units in the muscle, which resulted in more fascicles and stronger muscles. c. Weightlifting stimulated mitosis within the muscles, increasing the number of muscle fibers and making stronger muscles. d. Weightlifting tore the muscle fibers, causing an increase in scar tissue within the muscle, which resulted in an increase in the size of the muscle.

a. Weight lifting stimulated the production of more proteins and consequently an increase in sarcomeres and myofibrils within each cell.

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

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

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

a. between myofibrils but in fibers

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

a. contraction triggered by the release of calcium

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

a. decrease in the level of testosterone.

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

a. dystrophin

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

a. elasticity

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

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

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

a. is actively transported into the sarcoplasmic reticulum.

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

a. neuromuscular junction

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

a. skeletal

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

a. skeletal

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

a. skeletal

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

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

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.

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

a. specialized contractile organelles found in muscle cells

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

b. I band

Which of the following is most directly responsible for the coupling of excitation to contraction of skeletal muscle fibers? a. Action potentials. b. Calcium ions. c. Acetylcholine. d. Sodium ions.

b. Sodium ions.

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. T tubule c. sarcoplasmic reticulum d. Z disc

b. T tubule

What is the relationship between the number of motor neurons recruited and the number of skeletal muscle fibers innervated? a. A skeletal muscle fiber is innervated by multiple motor neurons. b. Typically, hundreds of skeletal muscle fibers are innervated by a single motor neuron. c. Motor neurons always innervate thousands of skeletal muscle fibers. d. A motor neuron typically innervates only one skeletal muscle fiber.

b. Typically, hundreds of skeletal muscle fibers are innervated by a single motor neuron.

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

b. a T tubule and two adjacent terminal cisterns

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

b. a motor unit

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

b. ansiotropic

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

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

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

b. associated with overused or strained postural muscles

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

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

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

b. calcium

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

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

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

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

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. slow oxidative fibers can convert to fast glycolytic fibers. d. fast oxidative fibers can convert to fast glycolytic fibers.

b. fast glycolytic fibers can convert to fast oxidative fibers

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

b. generate lots of power and depend on anaerobic pathways to make ATP

The point of attachment on the more movable bone in the illustration is called the _________ of the muscle. a. action b. insertion c. origin d. tendon

b. insertion

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

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

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

b. prevents the muscle from being overstretched

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

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

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. storage of fat for a ready energy source for active muscles c. provide a passageway for blood vessels and nerves d.bind muscle fibers together and contribute to elasticity of muscle

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

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

b. the terminal cisterns

During eccentric contraction, muscles resist gravity, acting like a__________

brake

During a muscle contraction, which of the following structures actually shorten? a.Actin b. Myosin c. Sarcomere d. Muscle fascicle e. Myofibril f. Tendon g. Muscle fiber

c, d, e, g

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

c. A band

Excitation-contraction coupling is a series of events that occur after the events of the neuromuscular junction have transpired. The term excitation refers to which step in the process? a. Excitation refers to the shape change that occurs in voltage-sensitive proteins in the sarcolemma. b. Excitation refers to the release of calcium ions from the sarcoplasmic reticulum. c. Excitation, in this case, refers to the propagation of action potentials along the sarcolemma. d. Excitation refers to the propagation of action potentials along the axon of a motor neuron.

c. Excitation, in this case, refers to the propagation of action potentials along the sarcolemma.

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

c. H zone

What is the importance of acetylcholinesterase in the neuromuscular junction? a. It prevents stimulation of muscle fibers. 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 breaks down acetylcholine so that particular muscle fiber will not be stimulated again.

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

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. Acetylcholine diffuses out of vesicles at axon terminals and causes the concentric contraction to occur. c. 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. d.Norepinephrine diffuses out of vesicles at axon terminals and causes the concentric contraction to occur. e. Titin, a spring-like molecule that extends the length of the thick filaments, pulls the myofibrils toward the center of a sarcomere.

c. 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

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

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

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

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

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 oxidative fibers only. b. slow oxidative fibers only. c. a mixture of fiber types. d. fast glycolytic fibers only.

c. a mixture of fiber types

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

c. a sheet of dense connective tissue

Myoglobin a. is found within the T tubules. b. is released by the sarcoplasmic reticulum. 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 b. smooth c. cardiac

c. cardiac

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

c. cardiac

Type of muscle with cardiac discs a. skeletal b. smooth c. cardiac

c. cardiac

Type of muscle found in the heart a. skeletal muscle b. smooth muscle c. cardiac muscle

c. cardiac muscle

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

c. distal

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

c. fleshy attachment

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

c. muscle fibers degenerate and atrophy

What is name given to the regularly spaced infoldings of the sarcolemma? a. motor endplates b. sarcoplasmic reticulum c. transverse or T tubules d. terminal cisternae

c. terminal cisternae

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

c. the region where calcium ions bind

A triad is composed of a T-tubule and two adjacent terminal cisternae of the sarcoplasmic reticulum. How are these components connected? a. Potassium leak channels. b. Myosin cross-bridge binding sites. c. Voltage-gated sodium channels. d. A series of proteins that control calcium release.

d. A series of proteins that control calcium release

As Abe continued his fitness regimen, he started to think more about his muscle anatomy. He wondered how he was able to adjust the force generated by his muscles when he lifted different weights. His anatomy instructor explained motor units to him. Which of the following best explains how motor units are involved in controlling force exerted by a muscle? a. Each skeletal muscle fiber is innervated by a single motor neuron, so there are as many motor neurons as fibers within a single muscle. When more force is needed, additional motor neurons will be activated, and their individual fibers will contract. b. Each muscle has one motor neuron that can selectively activate as many fibers as are needed. When trying to lift heavier objects, a single motor neuron will just stimulate more fibers to contract. c. A motor unit is composed of all the muscle fibers within a single fascicle. Additional fascicles will be activated when more force is needed. d. A single motor neuron innervates a specific set of muscle fibers within each muscle. When more force is needed, more motor units are activated, which stimulates more muscle fibers to contract.

d. A single motor neuron innervates a specific set of muscle fibers within each muscle. When more force is needed, more motor units are activated, which stimulates more muscle fibers to contract.

Myofilaments __________. a. are responsible for shortening muscle cells b. are specific types of microfilaments c. include actin and myosin 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. Thighs need finer control of movement than do the fingers. c. The fingers are smaller than the thighs. 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.

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

d. a bundle of cells

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

d. aponeurosis

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

d. cardiac

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

d. excitability

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

d. mesoderm

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

d. 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. myofibrils become more abundant in the muscle cells. c. myofilaments become more abundant in the muscle cells. d. muscle cells divide mitotically

d. muscle cells divide mitotically

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

d. synaptic vesicles

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

d. the boundaries of two adjacent sarcomeres

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

d. the loss of muscle mass with age

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

d. the sarcomere is fully contracted

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

d. thin filaments occur.

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. Their tissues contract as a sheet. d. The cells of all three are striated. e. All three depend on myofilaments for contraction

e. All three depend on myofilaments for contraction

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. It disappears. d. The A bands overlap, due to the pull of the thin filaments on the thick filaments. e. None of the listed responses is correct.

e. None of the listed responses is correct

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

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

Acetylcholinesterase breaks down acetylcholine to prevent additional __________.

twitches