Muscular Quiz

Which of the following is NOT a primary function of muscle tissue

• Movement production

• ATP production

• Stabilizing body positions

• Moving substances within the body

This property of muscle is defined as the ability to stretch and extend without being damaged

• Excitability

• Contractability

• Extensibility

• Elasticity

How does skeletal muscle grow?

• Skeletal muscle hypertrophies, growing in size before dividing

• Myofibrils inside the myocyte grow in number and size, increasing the size of each individual cell

• Satellite cells build up the perimysium of muscles following intense activity

• Muscle cells become more efficient over time, the increased number of mitochondria make individual cells bigger over time

Dense sheet or broad band of connective tissue that surrounds muscles

• Myofascial adhesion

• Aponeuroses

• Collagen

• Fascia

Plasma membrane of a myocyte

• Epimysium

• Sarcolemma

• Sarcoplasm

• Sarcolipid bilayer

Assuming a well-nourished, well-hydrated subject: which chemical is most likely to run out FIRST during the contractile cycle, thus ending muscle contraction

• Adenosine triphosphate

• Calcium ion

• Acetylcholine

• Creatine phosphate

Membranous sacs which encircle each myofibril

• Sarcolemma

• Myosin Capsule

• Vacuole

• Sarcoplasmic Reticulum

Thick motor protein filament with outward projections that bind to its thin filament counterpart

• Actin

• Myosin

• Troponin

• Tropomyosin

Answer explanation

Remember: Actin? Act-THIN

ATPs role in the contraction cycle can be described as the following:

• ATP binds to troponin, which changes the shape of the protein and moves tropomyosin out of the way for myosin to bind to.

• ATP is expended at the sarcolemma, where the sodium-potassium pump uses it to move sodium inside the cell AGAINST the concentration gradient

• ATP binds to a head of a myosin filament and one of its phosphate groups is expended, detaching the myosin from the actin filament. The resulting ADP is unbound from myosin, which then binds to a new site on the actin filament.

• ATP binds to myosin, causing it to bind to an available site on an actin filament, expending one of its phosphate groups. Once the resulting ADP unbinds, the myosin detaches from the actin filament

How does acetylcholine get to the integral proteins of the sarcolemma in order for the contraction cycle to begin?

• It is produced in the soma, where it is then transported to the synaptic end bulb via vesicles, where it then awaits a neural action potential to send it into the synaptic cleft

• It is passively present in interstitial fluid, especially in that of the synaptic cleft, awaiting an action potential from the presynaptic neuron

• It is synthesized in the synaptic end bulb. Neural impulses (action potentials) release ACh into the synaptic cleft.

• It is produced in the CNS and travels from neuron to neuron through the dendrite-axon network, eventually reaching the synaptic end bulb where an action potential will signal its release into the synaptic cleft