The Muscular System Support Systems Unit 2

Functions of the Muscular System Heat Production (thermogenesis) Heat is a byproduct of muscle contraction Movement Facilitation Muscles shorten and pull on bones which produces movement Structure (postural support) Contraction of muscles keeps us upright and maintains posture

Functions cont. Protection of Internal Organs Contraction of abdominal muscles causes them to become hard and offers protection to the underlying organs Other muscles con contract prior to receiving a blow thus protection bones and soft tissue. Controls the volume of hollow organs Smooth muscle surrounds our hollow organs and contractions propel the substances through them, aid in their emptying, or helps control their volume Stomach and small intestines The bladder Blood vessels

Anterior Skeletal Muscles

Posterior Skeletal Muscles

Cardiac Muscle Striated – appears striped under a microscope Involuntary- no conscious control Found in the heart

Smooth Muscle Located in walls of hollow internal surfaces such as: blood vessels - stomach urinary bladder - intestines Non-striated in appearance Involuntary

Skeletal Muscle Attached to bones Striated appearance under a microscope Voluntary control (conscious control)

Diseases and Disorders of the Muscular System

Tendonitis Characterized by Inflammation of the tendons due to overuse or age-related changes of the tendon. Common in individuals who begin a new exercise or increase their level of exercise. Treatment includes: rest, ice, compression, and elevation (RICE).

Strains A tearing of a muscle or its attaching tendon Occurs when a muscle receives a stress that overcomes its strength Sudden, quick heavy lifting During sports While performing work tasks

Strains cont. 3 types of strains A 1st degree occurs when the muscle is stretched causing micro-tears in the muscle fibers A 2nd degree sprain occurs when the muscle or tendon is partially torn A 3rd degree sprain occurs when the muscle is completely ruptured Signs & symptoms include: Pain, especially when the muscle is contractiong which limits function Swelling Bruising Treatment includes Rest, Ice, Compression, Elevation

Muscle Spasm An involuntary muscle contraction Also called a “Charlie Horse” or “muscle cramp” Main causes are electrolyte imbalances, dehydration and fatigue

Muscle Spasm cont. Initial treatment is to put the muscle that has the spasm on stretch If spasm persists ice or heat can be used Prevention incudes maintaining a proper diet, drinking plenty of water and proper conditioning Sports drinks may be beneficial during exercise to help replace lost sodium due to sweating

Muscular Dystrophy An inherited disorder in which the muscles are missing a certain protein causing degeneration of muscle tissue Causes progressive weakness and loss of function of the affected muscles There is no cure but physical therapy can lessen the severity of the disorder.