MEDICAL PHYSIOLOGY

Detailed explanation-1: -Both calcium & magnesium are required for muscle contraction.

Detailed explanation-2: -Calcium ions are required for muscle contraction, as well as for nerve impulse transmission.

Detailed explanation-3: -Voltage-gated Na+ and K+ channels are responsible for the generation of action potentials in neurons and skeletal muscle cells. In the neuron, generation of an action potential produces the nerve impulse, whereas in the muscle cell it leads to the contraction of skeletal muscle.

Detailed explanation-4: -Muscle contraction takes place by the cyclic interaction of two-stranded helical actin filaments with protuberances from the myosin filaments known as cross-bridges. The nature of the contractile process demands that the myosin cross-bridge be highly polymorphic.