Question

a triad is composed of a t - tubule and two adjacent terminal cisternae of the sarcoplasmic reticulum. how are these components connected?
a series of proteins that control calcium release.
potassium leak channels.
myosin cross - bridge binding sites.
voltage - gated sodium channels.

Explanation:

Triads are important in muscle contraction. T - tubules (transverse tubules) are invaginations of the sarcolemma. The terminal cisternae of the sarcoplasmic reticulum store calcium. A series of proteins (such as dihydropyridine receptors on T - tubules and ryanodine receptors on sarcoplasmic reticulum) control calcium release. Potassium leak channels are involved in maintaining resting membrane potential. Myosin cross - bridge binding sites are on actin filaments. Voltage - gated sodium channels are involved in action potential generation.

Answer:

A. A series of proteins that control calcium release.