The Equine Muscular System Equine Science

Muscles Function: One or more nerves bring commands AND send signals Provide movement Active organs of motion Contract or change shape when stimulated One or more nerves bring commands AND send signals Red flesh Make up about 50% of total body weight

Types of Muscles Smooth (Involuntary) Cardiac (Involuntary Striated) Skeletal (Striated)

Smooth Muscle Also called visceral muscle Location: Digestive system Uterus Capable of prolonged periods of activity Peristalsis: wavelike contractions of digestive system muscles Contraction is involuntary

Cardiac Muscle Location: ONLY found in the heart Requires NO nerve stimulus Requires NO conscious control Rate of contraction controlled by the nervous system

Skeletal Muscle Move the body voluntarily Usually attached to the bony levers of the skeleton Utilizes tendons to transmit the pull of the muscle Permits several muscles to attach at one point Generally arranged in pairs Become fatigued and require rest

Skeletal Muscle Extensor: extends a joint and brings bones into alignment Flexor: bends the joint Some muscles can act as both Opposed muscles act successively

Tendons Strong, cordlike structure that transmits the pull of the muscle as it contracts Tendon Sheath: synovial sac through which a tendon passes Tendon Bursa: synovial sac between the tendon and the surface over which it passes in a change of direction Both secrete synovia for lubrication Both usually found near joints

Five Major Functional Muscle Groups Forearms: allow for smooth gait and absorb shock Quadriceps: (hindquarters) used for propulsion Pectorals: carrying space for lungs Back: support riders or packs Stomach: hold organs in place