TTU A&P2 Quiz 6 - Muscle Tissue

Which of the following is/are mechanism(s) to end neural transmission at the neuromuscular junction?

ACh is broken down into acetic acid and choline by the enzyme acetylcholinesterase (AChE). ACh diffuses away from the synaptic cleft.

Which of the following events most directly occurs due to an action potential generated by the motor neuron?

ACh is released at the synapse.

The post-synaptic reaction on the sarcolemma is short in duration. Which of the following explanations describes why the reaction of the sarcolemma is short in duration?

AChE acts to breakdown the ACh in the synaptic cleft. ACh diffuses out of the synaptic cleft.

The characteristic muscle stiffness associated with rigor mortis is due to the inability of myosin filaments to detach from the active site on actin filaments. What molecule is essential for this detachment?

ATP

The cross bridge cycle starts when _________.

Ca2+ from the sarcoplasmic reticulum binds to troponin

Which of the following statements is true?

The neurotransmitter is stored in the presynaptic motor neuron.

Which of these statements about skeletal muscles is FALSE?

Their fibers branch.

Sarcomere is best defined as __________.

a repeating functional unit of striated muscle

During neuromuscular transmission, the axon terminals release __________.

acetylcholine

Triads in skeletal muscle fibers function in __________.

calcium ion release

Titin is a(n) __________.

elastic protein

Muscle fibers are directly surrounded by which thin layer of connective tissue?

endomysium

The capillaries that wrap around each muscle fiber are located within the __________.

endomysium

What area of the thick filament binds to actin once its active binding sites are exposed?

myosin cross-bridge (head)

What is the function of the structure indicated by the arrows?

part of coupling the action potential (electrical event) to contraction (mechanical event)

Skeletal muscle does each of these EXCEPT __________.

pump blood

The action potential in skeletal muscle fibers is first generated on the __________.

sarcolemma

In response to an action potential along the transverse tubules, the __________ release(s) calcium ions into the sarcoplasm.

sarcoplasmic reticulum

What is the function of the structure indicated by the arrow?

storage of calcium

Which region of the sarcomere gives rise to the structure (Z line) indicated by the arrow?

the boundary between adjacent sarcomeres

Which region of the sarcomere gives rise to the structure (band or line) indicated by the arrow?

the region of the resting sarcomere that only contains thick filaments

Which region of the sarcomere gives rise to the structure (I band) indicated by the arrow?

the region of the sarcomere that contains only thin filaments

The muscle action potential penetrates deep into a fiber along the __________.

transverse tubules

What component of the thin filament binds to calcium once calcium is released from the terminal cisternae of the sarcoplasmic reticulum?

troponin