Calcium that will eventually enter the muscle cell to bind with troponin is stored in the .....

MUSCLE ANATOMY

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Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]

Calcium that will eventually enter the muscle cell to bind with troponin is stored in the ____

A	T-Tubule of the Muscle Cell
B	Sarcoplasmic Reticulum of the Muscle Cell
C	The Sarcolemma of the Muscle Cell
D	The interstitial space outside the muscle cell near the pre-synaptic terminal.

Explanation:

Detailed explanation-1: -When calcium binds to troponin, the troponin changes shape, removing tropomyosin from the binding sites. The sarcoplasmic reticulum stores calcium ions, which it releases when a muscle cell is stimulated; the calcium ions then enable the cross-bridge muscle contraction cycle.

Detailed explanation-2: -Each heartbeat is triggered by a pulse of intracellular calcium ions which bind to troponin on the actin-containing thin filaments of heart muscle cells, initiating a change in filament structure that allows myosin to bind and generate force.

Detailed explanation-3: -Once intracellular calcium levels are raised, calcium binds to either troponin C on actin filaments (in striated muscle) or calmodulin (CaM), which regulates myosin filaments (in smooth muscle).

Detailed explanation-4: -Calcium ions at rest are stored in the sarcoplasmic reticulum (SR) from which they are rapidly released upon the depolarisation of the sarcolemmal and transverse (T-) tubular membranes of the muscle cell.

There is 1 question to complete.

GENERAL ANATOMY

MUSCLE ANATOMY