Plasma membrane of a skeletal muscle fiber - _________Extension of the sarcolemma that dives into the muscle fiber and surrounds
- _________Modified smooth endoplasmic reticulum that wraps around the myofibrils and stores calcium ions - _________Point at which the sarcoplasmic reticulum swells where it meets a T-tubule - _________Rodlike bundle of contractile filaments found in muscle fibers - _________Long, filamentous proteins that constitute myofibrils - _________Myofilament composed of the contractile protein myosin - _________Myofilament composed of contractile protein actin and the regulatory proteins troponin and tropomyosin - ______
These are all parts of the skeletal muscle and they are all involved in the contraction of your muslces.
The sacrolemma is also known as the myolemma. It is a specialized plasma membrane of the skeletal muscle cell. It is an excitable membrane that shares similarities to the cell membrane of a neuron cell.
The T-tubule extends from the sarcolemma to the sarcoplasmic reticulum (SR). This is the smooth endoplasmic reticulum of the muscle cell. When the sarcolemma gets excited, it triggers the SR to release the calcium ions stored in it. The release of Calcium ions triggers the contraction of myofilaments.
There are two types of myofilaments, the thick myofilament and the thin myofilament. These myofilaments contain contractile proteins, actin and myosin. Thick myofilaments contain myosin where one thick myofilament contains 300 myosin molecules. Thin myofilaments contain contractile and regulatory proteins. These myofilamens make up myofibrils.
Gravity is not the same thing as magnetism. They are in fact entirely distinct forces. Gravity is a force that works with weight between two objects. Magnetism can pull or separate the two objects, depending on how the magnets point.
