What will cause a muscle to relax?
Relaxation: Relaxation occurs when stimulation of the nerve stops. Calcium is then pumped back into the sarcoplasmic reticulum breaking the link between actin and myosin. Actin and myosin return to their unbound state causing the muscle to relax.
ATP binding to myosin is a very exergonic reaction, with the result that ATP displaces actin from the myosin head as indicated by the equation below. Thus, it is often said that ATP is required for muscle relaxation. It is important to note that in relaxed muscle, myosin is in its high-energy conformational state.
- The gap junctions spread action potentials to support the synchronized contraction of the myocardium. In cardiac, skeletal, and some smooth muscle tissue, contraction occurs through a phenomenon known as excitation contraction coupling (ECC).
- A single motor neuron is able to innervate multiple muscle fibers, thereby causing the fibers to contract at the same time. Once innervated, the protein filaments within each skeletal muscle fiber slide past each other to produce a contraction, which is explained by the sliding filament theory.
- medical Definition of crossbridge. : the globular head of a myosin molecule that projects from a myosin filament in muscle and in the sliding filament hypothesis of muscle contraction is held to attach temporarily to an adjacent actin filament and draw it into the A band of a sarcomere between the myosin filaments.
Muscles which move bones act together in pairs. This means that as one muscle contracts, its partner relaxes. Then as the partner muscle contracts the first muscle relaxes again. The messages sent by the brain are 'contract' or 'relax'.
- Muscles which move bones act together in pairs. This means that as one muscle contracts, its partner relaxes. Then as the partner muscle contracts the first muscle relaxes again. The messages sent by the brain are 'contract' or 'relax'.
- Muscle tension refers to the condition in which muscles of the body remain semi-contracted for an extended period. Muscle tension is typically caused by the physiological effects of stress and can lead to episodes of back pain.
- The muscular system is composed of specialized cells called muscle fibers. Their predominant function is contractibility. Muscles, attached to bones or internal organs and blood vessels, are responsible for movement. Nearly all movement in the body is the result of muscle contraction.
Updated: 2nd October 2019