What is the role of action potential in the muscles?
When muscle cells are stimulated, they download and develop strength in one direction. Muscle cell stimulation is caused by nerve pulses transmitted from the central nervous system to the muscles. When the nerve pulse reaches the end of the neuron, it causes the transmission of action potential in the muscles, leading to contraction.
There are three types of muscle cells in the body that are cardiac, smooth and skeletal. The heart muscle is only in the heart and has its own inner method for concluding contracts, although nerves can stimulate to accelerate or slow down as needed. The smooth muscle is found in layers surrounding organs and is stimulated by an autonomous or involuntary nervous system. The skeletal muscle is formed by fibers and causes movement. The action potential in the muscles of the skeleton is transmitted by a somatic or voluntary nervous system. Theaxons of neurons encounter muscle cells at a neuromuscular intersection. To ensure that muscle contraction is simultaneous and fast, there are many neuromuscularh intersections found in the muscle. All these neurons send impulses simultaneously to initiate the action potential in the muscles. Having many neuromuscular intersections for each muscle allows the body to control the strength of contraction by changing the number of units that send the impulse to the muscle.
When the action potential reaches the end end of the axon on the neuromuscular connection, the vesicles associate with the cell membrane to allow the release of the neurotransmitter - acetylcholine. The neurotransmitter spreads through the gap between the neuron and the muscle cell until it reaches Sarolemma, a membrane surrounding the muscle cell. Acetylcholin causes a change in the permeability of Sarcolemma, so the ions sodium can enter and leave the membrane. This change of ions depolarizes the membrane and causes the burning of action potential in the muscles.
When the muscle is at rest, tropomyosin blocks the binding areas of myosin found on actin fibers. During the accountsCancer is joined by myosin and performs the type of rowing action along the actin fibers. This causes the muscles to download. To do this, myosin must be able to bind to actin, so tropomyosin must be moved.
Depolarization caused by nerve pulse spreads via Sarolemma and T - system of tubes connected to sarcoplasmic reticulum. The T i sarcoplasmic reticulum system contains calcium ions that relax when there is action potential in the muscles. Calcium ions differ in a muscle cell and connect to a protein called troponin, which is connected to tropomyosin fibers found on actin fibers. Troponin changes the shape when the ions connect to it, which moves the fibers of tropomyosin and releases the binding areas of myosin along the actin fibers. Myosin can now come into contact with actin and cause muscle contraction.