Rigor mortis sets in when there is no calcium to bind to troponin.

SYNAPTIC PHYSIOLOGY

Please wait while the activity loads.
If this activity does not load, try refreshing your browser. Also, this page requires javascript. Please visit using a browser with javascript enabled.

If loading fails, click here to try again

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

A	True
B	False
C	Either A or B
D	None of the above

Explanation:

Detailed explanation-1: -Troponin plays a central role in the calcium-regulation of muscle contraction: Troponin is the sole calcium-binding component of thin filaments (actin-tropomyosin-troponin complex) of striated muscles. Thin filaments without troponin support contraction irrespective of calcium concentration.

Detailed explanation-2: -Option A: Rigor Mortis is an irreversible change. Its effects cannot be reversed. Hence, this is the incorrect option.

Detailed explanation-3: -In the rigor hastened by calcium the effects of the extensor muscles mostly prevail; in the rigor following magnesium injection, on the other hand, either the flexor muscles prevail or the muscles become stiff in the original position of the animal at death.

Detailed explanation-4: -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.

There is 1 question to complete.