Muscular System This is what happens without muscles “The power system”

Responsible for all body movement. #One Function Responsible for all body movement.

Responsible for body form and shape (Posture) #Two Function

Responsible for body heat and maintaining body temperature. #Three Function

Test Your Gray Matter…. Muscles are responsible for producing most of our : White blood cells, Hormones, Protein synthesis, or Body Heat.

Types of Muscles Skeletal Muscle Smooth Muscle Cardiac Muscle Attached to bone Visceral muscle Found only in the heart Voluntary Involuntary

Skeletal Muscles Attached to bone Striated (striped) appearance Voluntary Sarcolemma = cell membrane Contract quickly, fatigue easily, can’t maintain contraction for a long period of time

Test your skeletal muscles… Open and close your dominant hand until the teacher tells you to stop.             

Smooth Muscle Visceral (organ) muscle Found in the walls of digestive system, uterus, and blood vessels Cells small and spindle shaped Involuntary – ANS Controlled Act slowly, do not tire easily, can remain contracted for a long time.

Cardiac Muscle Found in heart Striated and branched Involuntary Cells are fused, when one contracts, they all contract (HB)

Test your gray matter.. Which of the following muscles are considered “voluntary” Which kind of muscle forms the walls of the heart? Striated, cardiac, skeletal, visceral Cardiac, Skeletal, Smooth, Visceral

Sphincter Special circular muscles in openings of esophagus and stomach, and small intestine, anus, urethra and mouth AKA: dilator muscles

Characteristics of Muscles Contractibility Excitability Extensibility Elasticity 1.05 Understand the functions and disorders of the muscular system

Muscle Characteristics The ability of a muscle to reduce the distance between the parts of its content or the space it surrounds. The ability to respond to certain stimuli by producing impulses. The ability to be stretched. Ability of muscle to return to its original length when relaxing. Contractibility Excitability Extensibility Elasticity

Muscular system structures Connective tissue Tendons dense bands that connect skeletal muscle to the bone 1.04 Remember the structures of the muscular system

Structures of the muscular system Connective tissue Fascia Fibrous connective tissue sheets that wrap around muscle bundles 1.04 Remember the structures of the muscular system

Sources of heat / energy For muscles to contract and do their work they need energy ATP – adenosine triphosphate – a major source of energy found in the muscle cell. When muscle is stimulated, ATP is released, which produces heat and energy to contract muscle. Lactic acid – a by-product of cell metabolism

Muscle Movement Muscle moves bones by pulling on them. As a muscle contracts, it pulls the Insertion one closer to the Origin bone. Movement occurs at the joint between the origin and the insertion. Rule: A muscle’s insertion bone moves toward its origin bone. Muscle Movement

Groups of muscles usually contract to produce a single movement muscle whose contraction is mainly responsible for producing a given movement Prime mover

Antagonist muscle whose actions oppose the action of prime mover in any given movement.

Synergist helps steady a movement and stabilize joint activity.

When the antagonist muscles contract, they produce a movement opposite to that of the prime movers. Motor Unit – a motor neuron plus all the muscle fibers it stimulates. Neuromuscular Junction – the junction between the motor neuron’s fiber which transmits the impulse – and the muscle cell membrane.

Acetylcholine Fatigue Oxygen Debt Muscle chemical neurotransmitter, diffuses across the synaptic cleft (carries impulse across synaptic cleft) caused by the accumulation of lactic acid in the muscles after exercise, the amount of oxygen needed by the muscle to change lactic acid back to glucose. Acetylcholine Fatigue Oxygen Debt

Movement: Skeletal Muscle Receptors in muscles provide the brain with information about body position and movement. The brain controls the contraction of skeletal muscle. 1.05 Understand the functions and disorders of the muscular system

Movement: Digestive System The nervous system regulates the speed at which food moves through the digestive tract. 1.05 Understand the functions and disorders of the muscular system

Exercise and training Will affect the size, structure and strength of a muscle. If injured, muscles can only regenerate a limited degree. If severe injury, muscle tissue may be replaced with scar (connective) tissue.

Benefits of exercising Improved muscle coordination Improved respiratory and circulatory system to supply needs of an active muscular system Eliminate or reduce excessive fat. Improve joint movement. Increase muscle size

Atrophy vs hypertrophy Atrophy –wasting away of a muscle Hypertrophy – growth of a muscle due to repetitive usage

Muscle Tone John just got a cast off his leg. His calf muscle on the affected leg is 1” smaller in diameter than his other calf muscle. What happened? How do you explain this to him? 1.05 Understand the functions and disorders of the muscular system

Head & Neck Muscles 1.04 Remember the structures of the muscular system

Torso/Trunk (anterior) 1.04 Remember the structures of the muscular system

Torso/Trunk (anterior) 1.04 Remember the structures of the muscular system

Torso/Trunk (posterior) 1.04 Remember the structures of the muscular system

Upper extremities 1.04 Remember the structures of the muscular system

Lower extremities 1.04 Remember the structures of the muscular system

Musculoskeletal disorders - Strain a tear of the muscle resulting from excessive use Pain and swelling occur due to bleeding in the muscle Ice packs will help reduce swelling and stop bleeding Rest and OTC medicines also help.

Muscle spasm a sustained contraction of the muscle. Occurs from over usage.

Myalgia muscle pain

Fibromyalgia chronic disease that includes muscle pain lasting for 3 or more months S/S: HA, fatigue, numbness, tingling, and joint pain Tx – rest, exercise, medicines, chiropractic services, and massage.

Movement: Digestive System The nervous system regulates the speed at which food moves through the digestive tract. 1.05 Understand the functions and disorders of the muscular system

Hernia occurs when an organ protrudes through a weak muscle. Abdominal Inguinal Hiatal – occurs when the stomach pushes through the diaphragm.

Tetanus (lockjaw) infectious disease that causes continuous spasms of the voluntary muscles Caused by toxin from the bacillus: clostridium tetani enters the body through a wound Can be prevented by vaccine.

Muscular dystrophy muscle cells deteriorate most common is Duchenne’s MD:usually genetic defect Usually death occurs in late teens or early 20’s.

Myasthenia gravis muscle weakness and paralysis cause unknown: possible immune system defect.

TENDONITIS inflammation of a tendon