 FUNCTIONS: ◦ Body Movement ◦ Pump Blood Throughout body ◦ Move food through digestive system ◦ Control air movement in and out of the lungs

 CONTRACTION: Shortening of a muscle.  EXTENSION: stretching of a muscle.

 Muscles work in opposition, while one contracts, the other extends.  Antagonistic = work in opposition, muscles do this, so one muscle would be the antagonistic muscle to another one.  Examples = bicep/triceps quadriceps/hamstrings

 SMOOTH MUSCLE: control movements of internal organs. ◦ Involuntary movements…work without conscious control. ◦ Intestines, bronchi of the lungs, the bladder.

 SKELETAL MUSCLE: striped or striated muscles attached to the bones that cause body movement. ◦ Biceps, triceps. ◦ Largest part of the body’s muscular system. ◦ Voluntary movements, conscious control. ◦ FLEXORS: muscles that close a joint. ◦ EXTENSORS: muscles that open a joint.

 CARDIAC MUSCLE: striated tissue that forms the wall of the heart. ◦ Involuntary muscle. ◦ Heart contracts rhythmically about 100,000 times a day.

 ATROPHY: waste away (“Use it or lose it”)  MUSCLE TONE: the natural tension in the fibers of a muscle. ◦ Aerobic exercise, resistance training, balanced diet. ◦ Older adults…prevent loss of mobility, balance, and risk of falls. ◦ The heart is a muscle that needs “training”…regular exercise. ◦ Stretching, warm-up, cool down. ◦ As always safety.

 MUSCLE SORENESS: damage to the muscle fibers themselves. Muscle biopsies taken on the day after hard exercise show bleeding and disruption of the z-band filaments that hold muscle fibers together as they slide over each other during a contraction.

 MYASTHENIA GRAVIS: muscles become weak and easily fatigued. ◦ Eye muscles…drooping eyelids and double vision.  MUSCULAR DYSTROPHY: inherited disorder characterized by a progressive wasting away of skeletal muscles. ◦ No cure.

 MUSCLE STRAIN:  “pulled muscle”, tearing or stretching of muscles fibers as a result of suddenly pulling them to far.

 BRUISE: discolored area under the skin caused by a leakage of blood after an injury. After Femur fracture

 TENDINITIS: the inflammation of a tendon, usually caused by overuse.

 HERNIA: the protrusion of an organ of tissue through a weak area in the muscle.

 Cartilage = allows smooth movement at a joint – connects the ribs and is a cushion between vertebrae.  Ligaments = connect bone to bone at a joint.  Tendons = a band of fiber that connects muscles to bones.

 Muscle tissue is ◦ ¾ water ◦ The remaining ¼ is  20% protein substances  5% nonprotein and mineral substances.

 What is ATP? ◦ Adenosine Triphosphate is a nonprotein chemical substance in muscle tissue. It is a source of immediate energy for muscle contraction. What is Glycogen? - An organic compound in muscles. Stored in cells and used as the body needs energy.