The Muscular System

How many muscles???  There are more than 600 muscles in the human body!!!  Muscles: bundles of muscle fibers that are held together by connective tissue  They are:  Excitable  Contractible  Elastic  Extensible

 3 main types of muscle  What is the muscle that forms the walls of the heart?  Cardiac Muscle  What is the muscle found in the internal organs, such as the digestive and respiratory systems?  Visceral or smooth muscle  What is the muscle that is attached to bones and causes movement?  Skeletal muscle

What are the functions of skeletal muscle????  Movement via attachment to bone  Heat and energy production—muscle movement generates 85% of heat the keeps you warm  Maintains posture

Functions of Muscles Protects internal organs Moves food through GI system and fluids through ducts Muscle movement, such as walking, aids the flow of blood through the veins as it returns to the heart.

How do our bodies move??

 How are muscles attached to bones????  By tendons—tough fibrous connective tissue

 Some muscle attaches by a tough sheetlike membrane that covers and protects the tissue called Fascia

Origin=end of muscle attached to bone that does not move Insertion=the end that moves when the muscle contracts

Muscles in Action Stand up!!!! Follow these movements to practice the different actions performed by YOUR muscles Adduction=TOWARDS midline Abduction=AWAY from midline Flexion=decrease angle Extension=increase angle Rotation=turn

Muscles in Action Circumduction=one end moves in circle, one end stays still Pronation=downward Supination=upward Dorsiflexion=bend foot to knee Plantar flexion=bend foot away from knee

What happens to my muscles if I don’t use them???? If you don’t use muscles, whether paralyzed or due to illness, they atrophy. They shrink and become weak Also form contractures Severe tightening of muscles Seen in patients in coma, long term illness, other brain injuries, muscle diseases

Contractures

Diseases and Abnormal Conditions of the Muscles Fibromyalgia Chronic Widespread pain S/S: muscle stiffness, numbness, tingling, fatigue, headaches, sleep/mood issues Tx: pain relief such as PT, massage, exercise, medications, reducing stress

Muscular Dystrophy Inherited Chronic Progressive muscle atrophy Appears in early childhood S/S: healthy at first, then progressive muscle weakness as cells begin to die, eventually confined to WC, and death Tx: exploring gene therapy options

Myasthenia Gravis Chronic Improper transmission of nerve impulses Thought to be autoimmune disease S/S: progressive muscle weakness and paralysis and can be fatal, first sign can be eye weakness (droopy eyelids), difficulty with speech, eating Tx: Cholinesterase inhibitors, immunosuppressants, plasmapheresis (washing of blood cells)

Muscle spasms and strains Spasms=cramps, sudden painful involuntary muscle contractions Causes: dehydration, overexertion, poor circulation Tx: rest, hydration, stretching, massage (pressure) Strains=overstretching of muscle or injury to muscle or tendon Tx: rest, medication, ice, elevation, compression, heat