Understanding Muscle Fiber Types

What are the thick and thin fibers in skeletal muscles?

• Actin and Myosin

• Myosin and Actin

• Tropomyosin and Troponin

• Elastin and Titin

What is the role of tropomyosin in muscle contraction?

• It binds calcium ions.

• It provides elasticity to the muscle.

• It blocks the myosin-binding sites on actin molecules.

• It hydrolyzes ATP for energy.

Which type of stimulus is required for the strongest muscle contractions?

• Subthreshold stimulus

• Threshold stimulus

• Maximal stimulus

• Submaximal stimulus

What is rigor mortis?

• A condition of muscle relaxation after death

• A condition of muscle stiffness after death

• A type of muscle contraction

• A type of muscle fiber

What is the difference between isotonic and isometric contraction?

• Isotonic involves muscle length change, isometric does not.

• Isometric involves muscle length change, isotonic does not.

• Both involve muscle length change.

• Neither involves muscle length change.

What are the characteristics of smooth muscles compared to skeletal and cardiac muscles?

• They are voluntary and striated.

• They are involuntary and non-striated.

• They are voluntary and non-striated.

• They are involuntary and striated.

What is the sliding filament model of contraction?

• Actin filaments slide over myosin filaments, shortening the sarcomere.

• Myosin filaments slide over actin filaments, lengthening the sarcomere.

• Actin and myosin filaments do not interact.

• Myosin filaments slide over actin filaments, shortening the sarcomere.

What is the role of acetylcholine receptors on the motor end plate?

• They release calcium ions.

• They bind acetylcholine to initiate muscle contraction.

• They break down acetylcholine.

• They store glycogen.

Why do skeletal muscles store glycogen?

• To provide structural support

• To store energy for muscle contraction

• To transport oxygen

• To synthesize proteins

What is the difference between skeletal muscle tissue and neuronal tissue?

• Skeletal muscle tissue is excitable, neuronal tissue is not.

• Neuronal tissue is excitable, skeletal muscle tissue is not.

• Both are excitable tissues.

• Neither is excitable.