Understanding Skeletal Muscle Structure

Which type of muscle tissue is found in the heart?

• Cardiac muscle

• Skeletal muscle

• Visceral muscle

• Smooth muscle

What is the outermost connective tissue layer of a skeletal muscle called?

• Perimysium

• Endomysium

• Epimysium

• Sarcolemma

What are the cylindrical cells that make up muscle fibers known as?

• Sarcomeres

• Myofibrils

• Skeletal muscle cells

• Myofilaments

What are the dark bands in myofibrils called?

• H-zones

• Z-lines

• A-bands

• I-bands

Which protein is a component of the thick filaments in myofibrils?

• Myosin

• Tropomyosin

• Troponin

• Actin

What is the basic unit of contraction in a skeletal muscle?

• Myofilament

• Sarcomere

• Fascicle

• Myofibril

During muscle contraction, which band shortens?

• A-band

• I-band

• M-line

• H-zone

What is the specialized endoplasmic reticulum in muscle cells called?

• Sarcolemma

• Sarcoplasmic reticulum

• T-tubule

• Sarcoplasm

What structure is formed by a T-tubule and two terminal cisterns?

• Dyad

• Triad

• Sarcotubular system

• Sarcomere

What is the role of calcium in muscle contraction?

• It forms the Z-line.

• It is stored in the sarcoplasmic reticulum.

• It binds to myosin heads.

• It provides energy for contraction.