Muscle Physiology

Types of Muscle Skeletal Smooth Cardiac Attached to bones Makes up 40% of body weight Responsible for locomotion, facial expressions, posture, respiratory movements, other types of body movement Voluntary in action; controlled by somatic motor neurons Smooth In the walls of hollow organs, blood vessels, eye, glands, uterus, skin Some functions: propel urine, mix food in digestive tract, dilating/constricting pupils, regulating blood flow, In some locations, autorhythmic Controlled involuntarily by endocrine and autonomic nervous systems Cardiac Heart: major source of movement of blood Autorhythmic

1- Skeletal Muscle Structure Muscle = group of fascicles Muscle fibers extend length of muscle from tendon to tendon

Connective Tissue of a Muscle Epimysium. Dense regular c.t. surrounding entire muscle Separates muscle from surrounding tissues and organs Connected to the deep fascia Perimysium. Collagen and elastic fibers surrounding a group of muscle fibers called a fascicle Contains b.v and nerves Endomysium. Loose connective tissue that surrounds individual muscle fibers Also contains b.v., nerves, and satellite cells (embryonic stem cells function in repair of muscle tissue Collagen fibers of all 3 layers come together at each end of muscle to form a tendon or aponeurosis.

Connective Tissue of a Muscle Epimysium. Dense regular c.t. surrounding entire muscle Separates muscle from surrounding tissues and organs

Connective Tissue of a Muscle Perimysium. Collagen and elastic fibers surrounding a group of muscle fibers called a fascicle

Connective Tissue of a Muscle Endomysium. Loose connective tissue that surrounds individual muscle fibers

Fig. 10.03

Fig. 10.04

Fig. 10.06

Fig. 10.07