Understanding Skeletal Muscle Function

What controls skeletal muscles?

• Voluntary control

• Autonomic nervous system

• Spinal reflexes

• Cardiac impulses

What are fascicles?

• Bundles of muscle fibers

• Types of muscle cells

• Nerve bundles

• Connective tissue layers

What is the role of motor units in skeletal muscles?

• Insulate muscle fibers

• Connect muscles to bones

• Signal contraction

• Provide energy

What protein forms thick filaments in muscles?

• Actin

• Collagen

• Myosin

• Elastin

What is the function of sarcomeres in muscle fibers?

• Contract and relax muscles

• Store nutrients

• Protect muscle fibers

• Produce myosin

How do myosin and actin interact during muscle contraction?

• Myosin binds to actin

• Actin repels myosin

• Actin encapsulates myosin

• Myosin decomposes actin

What initiates the muscle contraction process?

• Myosin detachment

• Action potential in motor nerve

• ATP synthesis

• Calcium release

What is the role of T-tubules in muscle contraction?

• Transmit action potentials

• Produce myosin

• Store ATP

• Synthesize proteins

What happens during the 'excitation' step of muscle contraction?

• ATP is consumed

• Myosin binds to actin

• Calcium ions are released

• Action potential depolarizes sarcolemma

During the 'coupling' step, what crucial element is released from the sarcoplasmic reticulum?

• Potassium

• Chloride

• Sodium

• Calcium