Malignant hyperthermia is a rare but frequently lethal condition stimulated by certain anesthetics. suddenly the individual's muscles become rigid, heart rate shoots up, and body temperature rises rapidly. those at risk for malignant hyperthermia have a mutation in the gene that codes for the ryanodine receptor. the mutation results in excessive opening of the ca2* channels in the sarcoplasmic reticulum. knowing this cause of the condition, how can you explain all of its manifestations temperature, heart rate, and muscle tension?