What is the structure of skeletal muscles?
Skeletal muscles structure differs slightly from other two main types of muscles, heart and smooth muscles. Also called striped muscles, the skeletal muscle has a striped look due to two overlapping proteins that allow the muscle to download quickly. Extended cylindrical cells, which are also called muscle fibers, also form the structure of skeletal muscles. Each skeletal cell contains several hundred nuclei, unlike a single nucleus found in cells of other types of muscles. Muscle fibers have membranes and fibers called myofibrils, structures that are particularly important for their contractile function.
Three types of muscle tissue, including skeletal, heart and smooth muscles, form a human muscle system. Skeletal muscles are the most abundant type of muscles because they cover and provide the movement of the whole skeleton of the human body. They have two alternative names: striped muscles, because of their cross-view and voluntary muscles, because the conscious mind can control their actions. Muscle fibers with quickly withThey pull due to the presence of myofibrils or small fibers that contain two overlapping proteins called actin and myosin. As can be seen under the microscope, dark belts consisting of myosin overlapping light strips created by actin, leading to a striped appearance of skeletal muscle structure.
Muscle contraction is possible mostly by the chemical reaction between myosin and actin and controlled by calcium ions and two other proteins that cooperate, call troponin and tropomyosin. When calcium ions are released from sarcoplasmic reticula of skeletal muscles, troponin, chemical reactions, and thus muscle contraction occur. The release of calcium ions triggers troponin to change the position, causing tropomyosin to be a push -in, how to make a way to "reach" and communicate with actin. When calcium ions remain stored in sarcoplasmic reticulum, there is no gossipIt is contracted, and therefore it is said that the muscle is "resting" or in a relaxed state.
The skeletal muscle structure also consists of two membrane systems called plasma or cell membrane and sarcoplasmic reticulus that are involved in the contraction process. Each muscle fiber is surrounded by a cell membrane that has a tubelike extension called transverse tubules. The transmission of electrical pulses that activate the contraction occurs using transverse tubes that reach deep into the muscle fibers. Meanwhile, the sarcoplasmic reticulum, which is located inside the muscle fibers, relaxes calcium during muscle contraction and stores calcium during muscle relaxation. A characteristic pattern called triad is created, because sarcoplasmic reticulum is located very near the transverse tubules.