Chapter 14 Lesson 2 – The Muscular System

FUNCTIONS All movements Pump blood throughout body Move food through digestive system Control movement of air in and out of your lungs

Contraction = the shortening of a muscle Extension = the stretching of a muscle Example – bicep/tricep

3 TYPES OF MUSCLES SMOOTH MUSCLE Type of muscle concerned with movements of internal organs Intestines, bronchi of lungs, the bladder, Involuntary – work without control SKELETAL MUSCLE Striped, or striated, muscles attached to bones that cause body movements Form the largest part of the body’s M.S. ( > 600) Voluntary - under conscious control CARDIAC MUSCLE Special type of striated tissue that forms the walls of the heart Heart is most important muscle in body

3 TYPES OF MUSCLES SMOOTH SKELETAL CARDIAC

Care of muscular system More use = more efficient/strong Exercise strengthens the heart (more blood pumped in a 1 beat) Practice good posture Increase muscle tone Eat nutritious foods “Use it or lose it” – an unused muscle will atrophy, or waste away

Lasting PROBLEMS Muscular dystrophy Inherited disorder Progressive wasting away of skeletal muscles No cure, but weakening can be delayed with exercise

INJURY RELATED PROBLEMS MUSCLE STRAIN BRUISE aka “pulled muscle” = tearing or stretching of muscle fibers Usually occur in large muscles Treatment = ice, wrap, rest Discolored area under the skin caused by leakage of blood after an injury Treatment = ice can reduce pain/swelling

INJURIES CONT… Inflammation of a tendon usually caused by overuse TENDINITIS HERNIA Inflammation of a tendon usually caused by overuse Symptoms = pain, tenderness, restricted movement Treatment = anti-inflam. meds Protrusion of an organ or tissue through a weak area in the muscle Abdominal – protrudes through weak area in abd. wall may appear after lifting heavy objects Surgery