Physio Exam 3 Muscles

Skeletal muscles are attached to bones via _____________ which transfer the contraction tension and allow for the movement of the bone.

Tendons

The green tube like structure labeled in the diagram is in the _______________ ______________ of the sarcoplasmic reticulum.

Terminal Cisternae

The _____________ ______________ of the sarcoplasmic reticulum function in the storage and release of calcium ions during muscle contraction.

Terminal cisternae

During Muscle contraction: A: the actin and myosin overlap each other B: The M line disappears C: the actin and myosin get shorter D: the H zone gets larger

A

The tunica externa is composed of A: connective tissue B: Smooth muscle C: endothelial cells D: basement membrane E: elastic fibers

A

What are the columns of muscle produced by the extension of the epimysium into the body of the muscle called? A: Fascicles B: Muscle Fibers C: Perimysium D: Myofilament

A

When increasing numbers of motor units are activated, more force is generated. This is called ________. A: Motor unit recruitment B: Temporal summation C: partial tetanus D: complete tetanus

A

Which label marks the T-tubules or transverse tubules? B A C

A

Which movement decreases the angle of a joint? A: Flexion B: Extension C: Adduction D: Abduction

A

Which of the following must occur for a muscle fiber to relax? A: the concentration of calcium in the cytoplasm must decrease. B: The concentration of calcium in the cytoplasm must increase. C: ATP must be pumped back into the terminal cisternae of the SR D: Tropomyosin must be removed from actin

A

Which the skeletal muscle cells, the dark bands also called the _______ bands are made up of actin and myosin proteins.

A

Fast oxidative or Type IIA fibers: A: have a high myoglobin content B: have the fastest twitch rate of all three types of fibers C: Have a low myoglobin content D: are aerobic E: are Anaerobic

A, D,

Match the type of calcium channel with its location. Calcium release Channel Voltage gated calcium channel A: Located in the terminal cisternae of SR; releases calcium in response to shape chagnes of another ion channel B: Located in the transverse tubules; opens in response to the action potential

A, B,

What molecules can be used to recharge ADP into ATP during short intense bouts of exercise? A: Phosphocreatine B: Creatine phosphate C: ATP kinase D: Phosphokinase

A, B,

Which of the following actions apply to the myosin cross bridge heads? A: Part of the myosin protein B: Bind to and pull on actin C: Part of the actin protein D: Bind to calcium and move tropomyosin

A, B,

Which of the following are examples of isotonic contractions? A: Picking up your leg during walking B: Picking up a pencil C: trying to lift a car but not succeeding

A, B,

How is ATP used during muscle contraction? A: To fuel the pumps that move calcium back into the SR after contraction B: To break the bond between actin and myosin C: To energize the myosin heads and put them into position D: To uncover the active site on actin E: To bind to troponin causing the movement of tropomyosin

A, B, C,

The aerobic capacity: (Multiple answers) A: is also called the maximal oxygen uptake B: is the maximum rate of oxygen consumption C: is often expressed as the VO2 max D: is the percentage of the maximal oxygen uptake at which a significant rise in blood lactate levels occurs

A, B, C,

Which of the following are characteristics of single unit smooth muscle? A: Display pacemaker activity B: Respond to stretch C: Many gap junctions D: Must be stimulated by individual muscle fibers

A, B, C,

Which of the following are types of skeletal muscle fibers? A: Type II B: Type I C: Fast twitch D: Slow twitch E: Unitary

A, B, C, D,

The basal nuclei or basal ganglia: A: act through the rubrospinal tract. B: inhibit the lower motor neurons C: inhibit the upper motor neurons D: Include the caudate nucleus, putamen, and globus pallidus

A, B, D,

What changes in an exercising muscle may contribute to fatigue? A: depletion of muscle glycogen B: Decrease in ATP at the junction of the T-tubules and SR C: Decreased ADP in the cytoplasm D: Increased concentration of PO

A, B, D,

Which of the following occur to gradually increase the force of a muscle contraction? A: Recruit more motor units B: Recruit larger motor units C: Increase the amplitude of each stimulus send to the muscle fibers from the neuron D: Increase the rate of motor unit stimulus

A, B, D,

Place the structures in order from largest to smallest subunit. (type corresponding letters from largest to smallest) A: Fasicle B: Fiber C: Myofilament D: Myofibril E: Globular actin

A, B, D, C, E

How does smooth muscle innervation differ from skeletal muscle innervation? A: Smooth muscle cells have receptors for neurotransmitters across their entire membrane. B: Smooth muscle cells have receptors for neurotransmitters only at the variscosities and neuromuscular junction. C: In smooth muscle, each wave of neurotransmitters released stimulate a group of cells instead of just one cell.

A, C,

Respiratory gases are transported by __________. A: erythrocytes B: leukocytes C: Plasma D: Platelets

A, C,

What are the series of elastic components of muscle? A: Tendons and Connective Tissue B: Troponin and Tropomyosin C: Elastic structures of muscle fibers D: Actin and Myosin

A, C,

Which of the following are true of cardiac muscle but not of skeletal muscle? A: Signal to contract is passed between cells via gap junctions B: Contracts in motor units C: Undergoes excitation contraction coupling D: The entire myocardium contracts as a unit

A, C,

The power stroke: A: Moves the actin towards the center of the sarcomere B: Removes tropomyosin from the active sites on the actin C: is produced by the myosin cross bridge D: generates the contractile force in the muscle cell

A, C, D,

The optimal Muscle length: A: Is close to the normal resting length of muscle due to tendon insertion points. B: Is the length at which the muscles are the most contracted. C: Is the length at which the muscle is generating the least force. D: is the length where the most actin and myosin interactions can take place and the most force is generated.

A, D

During an isotonic contraction: A: the muscle shortens B: The muscle does not contract C: The tension produced by the muscle is less than the load D: The tension produced by the muscle is greater than the load

A, D,

What occurs in muscle as we age? A: the secretion of myostatin and transforming growth factor increases B: the secretion of myostatin and transforming growth factor decreases C: the numbers of satellite cells increase D: the number of satellite cells decrease

A, D,

Which of the following change during contraction? A: The H band gets smaller B: The A band gets smaller C: The thin filament shortens D: The I band gets smaller

A, D,

In Muscle, ATP is used: A: for calcium transport back to the sarcoplasmic reticulum B: by calcium release channels to increase sarcoplasm calcium concentrations C: by troponin for moving tropomyosin off of actin's active sites D: by myosin ATPase to energize the myosin cross bridge E: by myosin ATPase to break the bond between actin and myosin

A, D, E,

Match the Fiber type with its unique characteristics. (Type letters in corresponding order) Slow Twitch (Type I) Fast Twitch (Type IIA) Fast Twitch (Type IIX) A: Intermediate diameter, intermediate glycogen content, intermediate resistance to fatigue, high myoglobin, fast twitch rate. B: Small Diameter, low glycogen content, High resistance to fatigue, High myoglobin, Slow twitch rate. C: Large diameter, High glycogen content, low resistance to fatigue, low myoglobin, fast twitch rate.

B, A, C

Put the motor units (Listed by innervation ratio) in order from first activated to last to be activated. A: 1:100 B: 1:25 C: 1:1000

B, A, C,

Due to the lag time required by the cardiovascular system, the skeletal muscles metabolize __________ for the first 45-90 Seconds of moderate exercise.

Anaerobically

When a muscle contracts isometrically, A: no tension develops within the muscle B: the muscle does not shorten C: the load is greater than or equal to the tension that the muscle can produce D: the muscle uses no ATP

B, C

After flexion of the biceps brachii and forearm, the muscle group that acts on the same joint to produce extension is called the __________ muscle group.

Antagonistic

As the load on the muscle increases, the velocity of shortening: A: is not effected B: Decreases C: Increases

B

Creatine phosphate: A: is produced during anaerobic respiration B: is used to convert ADP into ATP C: Stores oxygen for use during exercise D: Pumps calcium back into the SR

B

How is contraction initiated in cardiac muscle? A: The AP triggers contraction via excitation contraction coupling. B: A pacemaker region depolarizes. C: Motor units are stimulated

B

In skeletal muscle calcium binds to troponin, while in smooth muscle calcium binds to _______ causing the activation of _________. A: Calmodulin; actin B: Calmodulin; myosin C: troponin; tropomyosin D: Myosin; actin

B

Unlike skeletal muscle, smooth muscle cells do not contain: A: Myosin B: Sarcomeres C: Dense bodies D: Actin

B

What is the H band of the sarcomere? A: the attachment point of the actin to the cytoskeleton of the cell B: The area that contains only thick filaments C: The area that contains only thin filaments D: The attachment point of the myosin to the cytoskeleton of the cell

B

What is the function of tropomyosin in muscle contraction? A: To move/lever tropomyosin off the active site of actin so that myosin can bind to it B: To block myosin from binding to actin when there is no contraction signal C: To bind to the myosin head and cock it back (energize it) D: To bind to actin and initiate the power stroke E: To break the bond between actin and myosin when the contraction is finished.

B

What is the origin of a muscle? A: The tissue that gives rise to muscle tissue during development B: The attachment point of the muscle on the bone that does not move C: The attachment point of the muscle on the bone that moves D: The start point of a muscle movement during flexion

B

What is the process that activates larger motor units as more strength is needed? A: Tetanus B: Motor unit recruitment C: Temporal summation D: Excitation contraction coupling

B

What stimulates the release of calcium from the sarcoplasmic reticulum in cardiac muscle cells? A: Excitation contraction coupling between the T Tubules and the sarcoplasmic reticulum. B: Extracellular calcium from the opening of the voltage gated Ca++ channels C: ATP pumping of calcium D: Acetylcholine binding

B

When the biceps brachii of the arm contracts, the angle between the bones of the forearm and humerus decreases, what type of contraction is this? A: Abduction B: Flexion C: Adduction D: Extension

B

When the contraction of a muscle increases the angle between two articulated bones, the movement is defined as: A: Adduction B: Extension C: Abduction D: Flexion

B

Which label represents the H Zone of the sarcomere? A B E D C

B

Which of the following must be present to allow a muscle fiber to relax? A: Sodium B: ATP C: Acetylcholine D: Calcium

B

Which of the following will not increase the strength of a muscle contraction in a normal healthy muscle? A: diameter of the fiber B: Size of the motor neuron axon innervating the fiber C: Increasing the number of fibers stimulated D: Frequency of stimulus

B

If the calcium release channels were held open continuously, which of the following would be plausible? A: The muscle would not be stimulated to contract B: The muscle would not relax completely. C: Calcium levels in the sacroplasm would remain high D: The muscle would not contract

B, C,

Myostatin: A: stimulates muscle growth and repair B: inhibits muscle growth and repair C: inhibits satellite cell function D: Stimulates satellite cell function

B, C,

The anaerobic threshold: A: is also called the V02 Max B: is the percentage of the maximal oxygen uptake at which a significant rise in blood lactate levels occurs C: is also called the lactate threshold D: is the maximum rate of oxygen consumption by aerobic respiration

B, C,

Place the Events of Excitation Contraction coupling in order from the action potential being produced at the neuromuscular junction to finish: A: Ca release channels in SR open. B: Action potentials conducted along transverse tubules. C: AP opens voltage gated Ca channels in T-tubules. D: Ca binds to troponin beginning contraction. E: Ca diffuses out into sarcoplasm

B, C, A, E, D

The VO2 Max: A: represents the onset of anaerobic metabolism B: Is usually 15-20% higher for males than for females C: Is estimated by the relationship of heart rate to oxygen requirement during exercise D: is the maximal oxygen uptake or aerobic capacity

B, C, D

How does smooth muscle differ from skeletal muscle? A: Smooth muscle does not have actin or myosin. B: The thin filaments in smooth muscle cells are much longer. C: Smooth muscle does not have sarcomeres. D: The myosin in smooth muscle fibers is stacked perpendicular to the length of the cell.

B, C, D,

The action of the Ca ATPase pumps: A: causes the fiber to contract B: moves calcium into the SR C: Moves calcium against its gradient D: allows the fiber to relax E: moves calcium into the sarcoplasm

B, C, D,

Which of the following helps determine the maximal oxygen uptake? A: Time of day B: Size of person C: Sex D: Age

B, C, D,

During moderate exercise, a muscle obtains energy from: A: Amino acids B: muscle glycogen C: plasma glucose D: free fatty acids E: Triglycerides

B, C, D, E,

Which of the following statements about myosin are correct? A: At rest, each globular myosin head is attached to actin. B: Each globular myosin head has a binding site for actin as well as for ATP. C: The myosin heads act as myosin ATPase enzymes. D: Each globular myosin head has a binding site for calcium and one for actin. E: At rest, each globular myosin head is not attached to actin

B, C, E,

A eccentric contraction: A: causes the muscle to shorten B: causes the muscle to lengthen C: Produces tension that is greater than the load D: is an isotonic contractoin

B, D,

Match the Structure with the label. Sarcoplasm Myofibril Myofilament Sarcolemma A B C D

B, D, C, A

Which of the following are characterstics of skeletal Muscle: A: Intercalated discs B: Striated C: Uninucleate D: Branched Fibers E: Multinucleate

B, E,

A resting muscle obtains most of its energy needs from: A: Breakdown of triglycerides B: Conversion of muscle glycogen to glucose C: Aerobic respiration of fatty acids D: Conversion of liver glycogen to glucose

C

Actin: A: Is released from the sarcoplasmic Reticulum B: Is an enzyme that regulates acetylcholine C: Is a protein involved in muscle contraction D: Makes up the thick filament of the sarcomere

C

At rest, __________ inhibits contraction, while after a stimulus, __________ binding to calcium allows for contraction. A: Troponin; myosin B: myosin; tropomyosin C: tropomyosin; troponin D: troponin; tropomyosin

C

In Smooth muscle, Calcium ultimately regulates _____________ while in skeletal muscle calcium regulates the availability of actin binding sites. A: the availability of ATP B: the position of actin C: the phosphorylation of myosin cross bridges D: the binding of troponin to tropomyosin

C

In smooth muscle, the receptors for autonomic neurotransmitters are located: A: only at the junction or synapse with the axon B: at the varicosities C: across the entire surface of the cell D: at the dense bodies

C

What is a motor unit? A: The group of sarcomeres that make up a single muscle fiber B: A group of myofilaments that are bundled together C: A neuron and the muscle fibers it synapses with D: A nerve and all the muscles it connects with

C

What is the connective tissue sheath that surrounds each fascicle? A: Myofibril B: Epimysium C: Perimysium D: Endomysium

C

When sarcomere lengths are greater than 2.2um, the tension produced by the muscle during contraction: A: increases because there is no overlap between actin and myosin B: Decreases because actin and myosin overlap too much causing interference C: Decreases because there are fewer interactions between actin and myosin D: Increases because there are more interactions between actin and myosin.

C

Which of the following is an example of extension? A: The movement of your thigh when you rotate your hip to the side of your body. B: The movement of your thigh when your rotate your hip towards the midline of your body. C: The change in the angle between your arm and forearm when performing the up part of a push up. D: The change in the angle between your arm and forearm when performing the down part of a push up.

C

Which of the following is true of both temporal summation and motor unit recruitment? A: they both result in complete tetanus B: They increase the contraction phase of a muscle twitch C: They increase the force that a muscle generates D: They increase the number of cells that contract

C

Match the description with the muscle type in order (Type the letters in its corresponidng order): Skeletal Muscle Cardiac Muscle Smooth Muscle A: Unstriated, no sarcomeres, myogenic B: Striated, myogenic, intercalated disks C: Striated, innervatged in motor units, multinecleate

C, B, A

Asynchronous activation of different motor units in a muscle: A: leads to treppe B: produces incomplete tetanus C: Produces a smooth, sustained contraction D: Prevents muscle fatigue

C, D,

Which of the following are eccentric contractions? A: Trying and failing to pick up your car from the ground B: climbing up the stairs C: Putting down a heavy barbel on the gym floor D: lifting your textbook off the desk E: jumping off a ledge and landing with your legs flexed

C, E,

The arrangement of thick and thin filaments between Z lines forms a repeating subunit called a(n) ____________ which is the basic unit of striated muscle contraction.

Sarcomere

Before actin and myosin can bind, _________ binds to troponin C causing a conformational shape change that pulls tropomyosin off the F-actin's active site.

Calcium

When cardiac muscle cells are stimulated to contract, the influx of ____________ induces Ca2+ release from the sarcoplasmic reticulum.

Calcium

In smooth muscle, calcium combines with the protein __________ which then ultimately allows actin and myosin to bind.

Calmodulin

During muscle contraction, the majority of ATP is used: A: by actin for moving tropomyosin B: for Ca transport during relaxation C: for Ca transport during contraction D: by myosin ATPase for contraction

D

The VO2 max measures: A: the maximal rate of oxygen absorption of the alveoli B: The rate of lactate production C: the maximal volume of oxygen during inhalation D: the maximal oxygen uptake during exercise

D

Varying the number of muscle fibers participating in a contraction will produce: A: Temporal Summation B: Partial Tetanus C: Complete tetanus D: a graded contraction

D

What is another name for the prime mover of any skeletal movement? A: Antagonist B: Synergist C: Flexor D: Agonist

D

What is the fibrous connective tissue sheath that extends around the muscle? A: Endomysium B: Perimysium C: Fascicle D: Epimysium

D

What makes up the I bands in skeletal muscle? A: Actin and Myosin B: Myosin only C: Titin only D: Actin only

D

What makes up the thin filaments? A: Myosin B: Sarcoplasm C: Myofibrils D: Actin

D

What structure in the sarcomere serve to anchor the thick filaments and allow them to stay together during contraction? A: H zone B: Z bands or disks C: Troponin D: M lines

D

What type of contraction is produced when the tension created by the muscle is just greater than the load applied to the muscle? A: fused contraction B: Isometric contraction C: Treppe contraction D: Isotonic Contraction

D

Which label marks the sarcoplasmic reticulum?

D

Which label represents the A band of the sarcomere? E C B A D

D

Which of the labeled structures is a myofibril? B A C D

D

Place the events of the sliding filament theory in order from a fiber at rest to contraction. A: Ca++ binds to toponic C B: Myosin cross bridges bind to actin C: the myosin head binds an ATP molecule and detaches from the actin D: Ca++ is released from the sarcoplasmic reticulum E: the myosin head pivots towards the center of the sarcomere

D, A, B, E, C

when the muscle of your leg contract to move your lower leg back in order to kick a soccer ball, thus decreasing the angle between the femur and the tibia, the contraction produced is __________________

Flexion

The specialized region of the sarcolemma of a muscle fiber at the neuromuscular junction is called the ___________________

Motor End Plate

Which label represents the Z disks of the sarcomere? E C D B A

E

Each muscle fiber is enveloped by a thin connective tissue layer called the ________

Endomysium

The labeled structure forms the ________ ________________ of the sarcomere which anchor the thick filaments into the cell and prevent them from separating during contraction.

M Line

The process by which action potentials cause contraction in skeletal muscle is termed _________________ ____________ coupling.

Excitation Contraction

Contraction of this type of skeletal muscle, categorized as _________ muscles, increases the angle between their attached bones.

Extensor

On the diagram, the labeled structure is a(n) ________.

Fasciculus

When a skeletal muscle experiences a reduction in its ability to produce tension during exercise, the muscle has undergone ________________.

Fatigue

The ________________ ________________ of the sarcomere is the area that contains only thick filaments and is visible only in relaxed muscle.

H Band

The light bands in the skeletal muscle are also called _________ bands.

I

By Increasing the frequency of stimulus so that the relaxation time between twitches gets shorter but the strength of the contraction gets larger, the fiber will then undergo _________ tetanus, but when the fusion frequency is reached and there is no visible relaxation between twitches, ________ tetanus is reached.

Incomplete, Complete

The site of attachment of a muscle to the bone that it moves is its _________.

Insertion

The contractions of skeletal muscles produce movements of bones at joints, the joints act as _____________ to move the loads against which the muscle's force is exerted:

Levers

The thick filaments are primarily composed of the protein __________.

Myosin

The ________ of a muscle is the attachment point on the relatively immobile bone.

Origin

Stronger muscle contractions are produced by the process of ______________ during which the body stimulates more muscle fibers to contract.

Recruitment

The Plasma membrane of a skeletal muscle cell is also called the __________

Sarcolemma

The Calcium release channels found in the _____________ __________ are responsible for the passive diffusion of calcium ions into the sarcoplasm which initiates fiber contraction.

Sarcoplasmic Reticulum

The elastic structures of muscle and tendons, called the __________ __________ ___________, must be pulled tight before a muscle contraction can result in shortening.

Series elastic component

A muscle will _________ if the tension it develops is greater than or equal to the load it is under.

Shorten

Increasing the frequency of action potentials delivered to a muscle fiber so that the fiber does not relax and the response adds together is called ___________.

Summation

Narrow, membrane tunnels called the ____________ ___________ form from the sarcolemma and open to the extracellular environment next to the terminal cisternae of the sarcoplasmic reticulum.

Transverse Tubules

In order for actin to bind to myosin, the active sites on the actin molecule must be uncovered. This involves the movement of tropomyosin by the protein ____________.

Troponin

A muscle ___________ occurs when the muscle is stimulated with a single electric shock of sufficient voltage to cause it to contract and relax once.

Twitch

The Dark lines that can be seen in the middle of the I bands are the __________ ____________ which anchor the thin filaments into the cell and provide the boundary of sarcomere units.

Z Disc

When ________________ ___________________ form between myosin and actin, they pull the actin towards the M line of the sarcomere.

cross bridges

A cell in skeletal muscle is also called a muscle _______

fiber

_______________ contractions are produced by varying the number of muscle fibers participating in the contraction.

graded

The contraction of smooth muscle are slow and sustained due to their ability to enter a ___________ state where less ATP is hydrolyzed.

latch

During the _________ period, the action potential stimulates the release of calcium but the muscle has not yet begun to shorten.

latent

The basal nuclei have inhibitory effects on the ________ motor neurons. A: cerebellar B: afferent C: lower D: upper

lower

Each myofibril contains smaller subunits called _________ that are made up of actin and myosin.

myofilaments

During _________ the fibers are stimulated to contract before they relax completely, while ____________ produces more force by increasing the number of fibers that are contracting.

summation, recruitment

Most of the calcium in skeletal muscle cells is stored in the _____________ _____________

terminal cisternae