Vertebrate striated muscle contraction is controlled (regulated) by the action of the proteins troponin and tropomyosin on the actin filaments. Nervous stimulation causes a depolarisation of the muscle membrane (sarcolemma) which triggers the release of calcium ions from the sarcoplasmic reticulum.
n. 1  Abnormally fast or deep respiration, which results in the loss of carbon dioxide from the blood, thereby causing a fall in blood pressure, tingling of the extremities, and sometimes fainting.
Troubled or labored breathing is medically referred to as dyspnea, and excessively rapid breathing is medically referred to as tachypnea (also, polypnea). Breathing difficulties can affect cats of any breed or age, and the problem can quickly become life threatening.