Understanding Skeletal Muscle Structure

What is the basic functional unit of a skeletal muscle called?

• Sarcomere

• Myofibril

• Muscle fiber

• Fascicle

Which protein is primarily responsible for the contraction of skeletal muscles?

• Myosin

• Actin

• Tropomyosin

• Troponin

What is the connective tissue layer that surrounds an individual muscle fiber?

• Epimysium

• Perimysium

• Endomysium

• Sarcolemma

Which of the following is the thick filament in a sarcomere?

• Actin

• Myosin

• Troponin

• Tropomyosin

What is the term for the connective tissue that surrounds a bundle of muscle fibers?

• Epimysium

• Perimysium

• Endomysium

• Sarcolemma

Which of the following describes the sliding filament theory?

• Actin filaments slide over myosin filaments, shortening the sarcomere

• Myosin filaments slide over actin filaments, lengthening the sarcomere

• Actin and myosin filaments remain stationary, while the sarcomere shortens

• Myosin filaments slide over actin filaments, shortening the sarcomere

Label the muscle tissue

a

b

c

d

e

f

g

h

Endomysium

Bone

Perimysium

Tendon

Blood Vessel

Fascicle

Myofibril

Epimysium

Myofibrils are composed of individual:

• sarcomeres

• striations

• myofilaments

• fascicles

Thin filaments within a muscle fiber are called:

• actin

• myosin

• striation

• sarcolemma

What is the basic unit of a skeletal muscle called?

• Sarcomere

• Myofibril

• Muscle fiber

• Fascicle