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
10 Kinesthetic Muscle Principles 1. Muscles must have 2 point of attachment Origin stays stationary Insertion moves 2. Muscles attach to bones by tendons 3. Muscles must cross at least 1 joint to move 4. Muscles shorten when they contract 5. Muscles only pull 6. Muscles work in antagonistic pairs 7. Muscle fibers/tendons run in direction of pull 8. Muscles shape the bones 9. Muscles with parallel fibers are for speed and muscles that have angled fibers are for power 10. Muscles are named to help us remember something about each muscle Size, Shape, Directions of fibers, Action, Origin/ Insertion, or Combination
Anterior Skeletal Muscles
Posterior Skeletal Muscles
Full Body
Head & Eye
Trunk
Arm
Lower Body
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 Tendons Attach muscle to bones Striated appearance under a microscope Voluntary control (conscious control)
Skeletal Muscle Origin Attachment to the bone that is mostly immovable Insertion Attachment to the freely moving bone of its joint
Flexors Skeletal Muscle Muscle that decreases the angle of a joint Extensors Muscle that increases the angle of a joint Muscles can only pull
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 1 st degree occurs when the muscle is stretched causing micro-tears in the muscle fibers A 2 nd degree strain occurs when the muscle or tendon is partially torn A 3 rd degree strain occurs when the muscle is completely ruptured Signs & symptoms include: Pain, especially when the muscle is contracting 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.