Muscle Physiology

Types of Muscle• Skeletal

– 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– Controlled involuntarily by endocrine and autonomic nervous systems

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