When Ach enters the synaptic cleft (gap) it open chemically gated sodium channels that starts an action potential spreading through the sarcolemma of the myofibril. This action potential spreads down the T-tubules and "shocks" the sarcoplasmic reticulum into releasing calcium ions.
The concentration of calcium ion is greater in the sarcoplasmic reticulum compared to the sarcoplasm of a resting muscle. This is because the sarcoplasmic reticulum stores and releases calcium ions during muscle contraction.
The organelle that stores calcium in resting muscle cells is the sarcoplasmic reticulum. Calcium ions are released from the sarcoplasmic reticulum during muscle contraction to trigger muscle activity.
Calcium is released from the sarcoplasmic reticulum inside the muscle cell when a nerve signal triggers the release of calcium ions. This calcium binds to troponin on the actin filaments, which activates the contraction process in the muscle cell.
The calcium would come from the sarcoplasmic reticulum, which is a specialized structure found within skeletal muscle cells responsible for storing and releasing calcium ions for muscle contraction. A sudden release of large amounts of calcium from the sarcoplasmic reticulum can lead to uncontrolled muscle contractions and potentially muscle damage.
The immediate source of calcium ion for muscle fiber is the sarcoplasmic reticulum, a specialized organelle within muscle cells that stores and releases calcium ions in response to nerve signals. When a muscle cell is stimulated, calcium ions are rapidly released from the sarcoplasmic reticulum into the cytoplasm, triggering muscle contraction.
The sarcoplasmic reticulum is known for its storage of calcium ions in muscle cells.
The sarcoplasmic reticulum actively pumps calcium ions out of the cytosol to produce relaxation in muscle cells. This process is facilitated by the calcium pump located on the membrane of the sarcoplasmic reticulum, known as the sarcoplasmic/endoplasmic reticulum calcium ATPase (SERCA) pump.
The concentration of calcium ion is greater in the sarcoplasmic reticulum compared to the sarcoplasm of a resting muscle. This is because the sarcoplasmic reticulum stores and releases calcium ions during muscle contraction.
Calcium ions in muscle fibers are stored in the sarcoplasmic reticulum, which is a specialized form of endoplasmic reticulum found in muscle cells. When a muscle is stimulated to contract, the sarcoplasmic reticulum releases calcium ions into the cytoplasm, triggering muscle contraction.
Sarcoplasmic reticulum
Cardiac muscle relies solely on the sarcoplasmic reticulum as its calcium source for muscle contraction.
Sarcoplasmic reticulum is the type of skeletal muscle cell that functions in calcium storage. It plays a critical role in regulating intracellular calcium levels during muscle contraction and relaxation.
Calcium is transported out of the sarcoplasm by means of special ion pumps.
The part of the sarcoplasmic reticulum where calcium ions are stored is called the terminal cisternae. These structures are found at the ends of the sarcoplasmic reticulum and play a key role in releasing calcium ions into the muscle cell during muscle contraction.
sarcoplasmic reticulum
The sarcoplasmic reticulum is a special type of smooth endoplasmic reticulum. It releases calcium ions during muscle contraction and absorbs them during relaxation.
The organelle that stores calcium in resting muscle cells is the sarcoplasmic reticulum. Calcium ions are released from the sarcoplasmic reticulum during muscle contraction to trigger muscle activity.