chapter10

B

In the diagram, calcium ions will rush into this area.

Which type of muscle tissue contracts when excited by their own autorhythmic muscle fibers?

cardiac muscle

Which age group would be most susceptible to an increase in slow oxidative muscle fibers?

30+ years

Which of the regions of a sarcomere contain titin?

from M line to Z disc

What is the result of acetylcholine attaching to the ligand gates of the motor end plate?

The sarcolemma increases permeability to sodium

Smooth muscle tone is maintained by the prolonged presence of [_____] in the muscle cell’s cytosol?

calcium ions

All of the muscle fibers within the muscle are fully contracted and are in sustained contraction with no individual twitches detected due to high frequency of stimulation.

D

Which of the following structures are made of dense regular connective tissue?

A

Which region of a sarcomere contain thin filaments

Both I band and A band

In the diagram, which structure(s) moves towards the center of the sarcomere (closer together) when the fiber contracts

A

At the neuromuscular junction, _______must enter the synaptic end bulb to stimulate the release of ____________, which binds to ligand gates so ________can enter the muscle fiber

calcium ions; ACh, sodium ions

When athletes is preparing to perform a pull up, they hang from the bar. At this point, they are performing what type of contractions?

Isometric

For the muscle to contract and relax, what must be present (choose all that apply)?

ATP

Calcium ions

ACh

Writer's cramp can occur in Anatomy and Physiology lecture class. What factor would most likely contribute to the muscles not being able to relax?

a deficit of ATP keeping myosin from detaching

Which type of muscle tissue is capable of undergoing the stress-relaxation response when stretched?

single-unit smooth muscle fibers

Muscle damage can be indicated by…

myoglobin found in blood.

Which term describes a somatic motor neuron and all the skeletal muscle fibers it stimulates

motor unit

The relaxation phase of a muscle contraction is often prolonged in a fatigued muscle, raising the likelihood of fused summation of action potentials causing painful disturbances to a skeletal muscle. What disturbance is being described

Cramp

Which microscopic structure is found only in the cardiac muscle tissue?

intercalated discs

Myofibrils contain what type of proteins? Select all that apply

contractile proteins

regulatory proteins

structural proteins

Place the muscle tissue type in order from least to most ability to regenerate

skeletal, cardiac, smooth

What energizes the myosin head?

ATP hydrolysis reaction

Motor unit recruitment occurs when there is _______ in the number of active motor units within a skeletal muscle

Increase

In the diagram, where would you find stored Ca²⁺?

F

On the diagram, which layer is composed of dense irregular connective tissue and surrounds the entire muscle.?

C

Which statement explains the sarcomere appearance change during a muscle contraction?

The light A bands remain at a constant length

During muscle contractions , thin filaments are pulled towards the

M line

What proteins are found in thin filaments of skeletal muscle fibers? Select all that apply

tropomyosin

myosin

actin

nebulin

hypertrophy of fast oxidative-glycolytic fibers

Strength training would result in

Which characteristics describe both skeletal and cardiac muscle

Striations

Epimysium

The outermost layer of connective tissue surrounding a skeletal muscle is the

twitch contraction

A brief contraction of all muscle fibers in a motor unit in response to a single action potential moving down the somatic motor neuron is known as

In the diagram, what structure contains motor proteins that convert the energy in ATP into mechanical movements

C

In skeletal muscles, the combined amounts of creatine phosphate and ATP provide enough energy for the muscle to contract maximally for approximately

15 seconds

After prolonged strenuous exercise has stopped, heavy breathing will often continue for several minutes in order to provide the oxygen needed to

all of these choices are correct

In the diagram, how do action potentials penetrate the outside of the muscle fiber?

D

Which correctly lists the sequence of structures that action potentials must move through to excite skeletal muscle contraction?

axon of neuron, sarcolemma, T tubules

Which regions of the sarcomere contain thick filaments? Select all that apply

zone of overlap

A band

H zone

Which portion of this myogram shows a single twitch of the muscle?

A

The zone of overlap increases during the

contraction period

On the diagram, a tendon is formed by the merging of which structures

C, D, and H

Myasthenia Gravis is an autoimmune disorder that targets the ACh receptors at the NMJ and ultimately reduces the number of available receptors. Predict what happens if you treat the patient with a drug that inhibits the activity of acetylcholinesterase?

The drug will increase contraction.

Leg muscles are predominantly composed of which type of muscle fiber?

fast oxidative-glycolytic

Diltiazem is a calcium channel blocker, reducing free intracellular calcium. What stage of the myogram would be affected immediately?

Latent period

Which function do all three muscles perform

Moving and storing material throughout the body

In the diagram, acetylcholine is released from ____ and diffuses to _____.

B; E

Which functions as a motor protein in all three types of muscle tissue?

Myosin

Why would cardiac muscles have longer refractory periods than skeletal muscles. Choose the best answer?

to preserve the normal rhythm of the heart and prevent fatigue

Which disorder occurs when little to no proteins are produced to support the sarcolemma?

muscular dystrophy

When an athlete performs a pull up (raising their chin to a bar while their body hangs), the process of pulling the body up so the chin can touch the bar is

Concentric

Contraction of myofibrils within a muscle fiber begins when

calcium is released from the sarcoplasmic reticulum

In a neuromuscular junction, the effect of acetylcholine (ACh) binding to receptors on the motor end plate lasts only briefly due to

rapid destruction of ACh in the synaptic cleft by acetylcholinesterase.

Skeletal muscle contraction is triggered to begin when calcium is released from

terminal cisterns of sarcoplasmic reticulum

Which ATP production would be sufficient to run in place for one minute

anaerobic cellular respiration

After the fusion of myoblasts, the muscle fiber loses its ability to

go through mitosis

When an athlete performs a pull up (raising their chin to a bar while their body hangs), the process of lowering the body down is

Eccentric

Mitochondrial activity in skeletal muscle cells are usually efficient, but can have limited ATP production if

there is limited O₂availability

On the diagram, what structure is composed of the three connective tissue layers that extend past the muscle?

A

Which protein is used to reinforce the sarcolemma and help transmit the tension generated by the sarcomeres to the tendons?

dystrophin

Why will an individual who lifts weights build larger muscles?

skeletal muscles increase number of myofibrils but not number of cells

Which property of muscle gives it the ability to stretch without damage?

Extensibility

The opening of ligand gates on the sarcolemma is directly caused by

all choices are correctt

For crossbridges to occur, what events must happen? Select all that apply.

ATPase breaks down ATP

Calcium ions be present in the sarcoplasm

Myosin binding sites be exposed.

World class shot-putters will have a higher percentage of ______in their arm muscles.

fast glycolytic fibers