Chapter 9 Review

Which type of muscle lines the walls of hollow organs?

• smooth muscle

• skeletal muscle

• cardiac muscle

• striated muscle

Which of the following connective tissue sheaths line the a fascicle?

• epimysium

• perimysium

• endomysium

which of the following structures attach muscles to bones?

• tendon

• ligament

Answer explanation

ligaments connect two bones together

T or F: The H zone disappears during muscle contraction

• true

• false

each sarcomere is separated by a(n)

• Myosin filament

• A-band

• H-zone

• Z-disc

• M-line

T or F: There are several myofibrils within one sarcomere

• True

• False

Answer explanation

There are several SARCOMERES within one MYOFIBRIL. Sarcomeres are like the box cars of a train (myofibril is the whole train).

Which of the following stores calcium and releases it into to muscle fiber?

• Troponin

• Tropomyosin

• Sarcoplasmic reticulum

• Thin Filament (Actin)

• Sarcolemma

T or F: The thick and thin filaments both get shorter when a muscle contracts

• True

• False

Answer explanation

Elastic filament is the only filament that changes length. This causes the entire sarcomere to shorten. However, myosin & actin lengths do not change.

T or F: A cross bridge is formed when myosin heads bind to actin

• True

• False

Which of the following is an electrical signal that travels down the neuron and causes a change in membrane potential/voltage across a plasma membrane?

• Synaptic vesicle

• Action Potential (AP)

• Acetylcholine (ACh)

• Synaptic vesicle

Answer explanation

An AP is what causes calcium to enter the axon terminal.

THEN ACh is released from the axon and binds to receptors on the muscle fiber.

(ACh doesn't travel down the neuron from the spinal cord, but it is released from the axon terminal)