MUSCLE PHYSIOLOGY

Detailed explanation-1: -In contrast to both smooth muscle and cardiac muscle, skeletal muscle contracts primarily in response to a voluntary stimulus.

Detailed explanation-2: -In general, smooth muscles contract more slowly than do skeletal muscle fibers and maintain the contraction for longer periods of time. Smooth muscles can be divided into phasic muscles which contract more rapidly and tonic muscles which contract slowly and maintain tension for long periods of time.

Detailed explanation-3: -Skeletal muscle contains different fibers which allow for both rapid short-term contractions and slower, repeatable long-term contractions.

Detailed explanation-4: -A Muscle Contraction Is Triggered When an Action Potential Travels Along the Nerves to the Muscles. Muscle contraction begins when the nervous system generates a signal. The signal, an impulse called an action potential, travels through a type of nerve cell called a motor neuron.

Detailed explanation-5: -Skeletal muscle contraction and changes with exercise. (A) Neurotransmitter (acetylcholine, ACh) released from nerve endings binds to receptors (AChRs) on the muscle surface. The ensuing depolarization causes sodium channels to open, which elicits an action potential that propagates along the cell.