Muscle Physiology and Pathology: Healthy Versus Diseased Condition

Skeletal muscle represents approximately half of the total body mass and thus is the most abundant tissue of the equine body. The skeletal muscles induce smooth and coordinated body movements through their attachment to the skeleton. To ensure proper function, the muscles are highly vascularized and extensively innervated. It has been established that, during intense exercise, skeletal muscle receives more than 80% of the total blood flow in the horse
(Erickson, 1993). Contraction of muscle occurs when calcium flows into the sarcoplasma, triggering a series of events that include the binding of calcium to the muscle regulatory proteins, the cross linking of myosin with actin microfilaments, and the myosin-actin cross-bridge working stroke ...