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Muscular System. Stephen Springer Nolan Wool. Functions. Fluid Propulsion. Movement. Posture. Generate Heart Beat. Structure of Skeletal Muscle. Nervous Tissue. Skeletal Muscle Tissue. Connective Tissue. Blood. Structure of a Muscle Fiber. Cylindrical Sarcolemma covering
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Muscular System Stephen Springer Nolan Wool
Functions Fluid Propulsion Movement Posture Generate Heart Beat
Structure of Skeletal Muscle Nervous Tissue Skeletal Muscle Tissue Connective Tissue Blood
Structure of a Muscle Fiber • Cylindrical • Sarcolemma • covering • Sarcoplasm • cytoplasm • Myofibrils • Myosin • Actin
Relationship: Neuromuscular Junction • Stimulus travels from: Brain Neuron Neuron Motor Muscle Axon End Plate
Myosin and Actin Myosin Actin • Thick • Heads/Cross bridges • Thin • Binding Sites
Sliding Filament Theory • Heads of myosin attach to binding sites of actin • Myosin heads swivel • ATP releases myosin heads • Muscle relaxes
Muscle Contraction Calcium released from sarcoplasmic reticulum exposes the binding sites • Calcium binds to troponin • Tropomyosin pulls aside • Binding sites on actin exposed
Muscle Contraction (Cont.) • Myosin heads bind to actin • Power stroke occurs (swivel of heads) • Muscle contraction occurs
Muscle Contraction (Cont.) • ATP binds to myosin • Linkage is released • ATP splits into ADP and Phosphorous • Causes the myosin head to cock back • Cycle continues* • *If there are ATP & Calcium Ions
Energy and Oxygen Energy: • Glycolysis anaerobic • Cellular Respiration aerobic ATP Contraction
Fatigue Definition: When a muscle is exercised strenuously for a prolonged period and loses its ability to contract. Glycolysis • Fast-twitch muscle • Oxygen Debt • Lactic acid build up • +2 ATP Cause: • Low pH • Accumulation of Lactic Acid Cellular Respiration • Slow-twitch muscle • Includes the process of Glycolysis • +34 ATP
Cramping Definition: A painful condition in which a muscle undergoes a sustained involuntary contraction Causes: • Lack of ATP • Changes in extracellular fluid • Uncontrolled stimulation
Superficial Muscles Frontalis Zygomaticus Sternocleidomastoid Trapezius Deltiod Pectoralis Major Biceps Bracii Expeliarmis *Harry Potter Rectus Abdominus External Oblique Sartorius Gracilis Adductor Longus Rectus Femoris VastusLateralis FibularisLongus Tibialis Anterior Gastrocnemius Soleus Extensor DigitorumLongus
Posterior Superficial Muscles Occipitalis Sternocleidomastoid Trapezius Deltoid Triceps Bracii Infraspinatud Brachialis Teres Major Rhomboideus LatissimusDorsi Nobody Cares Gluteus Medius Gluteus Maximus Gluteus Maximus Adductor Magnus Biceps Femorous Semitendinosus Semimembranosus Gostrocnemius Soleus FibularisLongus Calcaneal Tendon
Origin & Insertion Origin: The immovable end of a muscle Insertion: The moveable end of a muscle
Prime Movers, Synergists, & Antagonists Synergists: • Helper muscles Prime Mover (agonist): • Mainly responsible for movement Antagonists: • Resist prime mover
Recruitment and Muscle Tone Muscle Tone: • Nerve impulses continuously sent from spinal cord Recruitment: • Increases number of active muscle fibers • Summation or Tetanic Increase of weight
Summation and Sustained Contraction Summation: • Combined individual twitches • Eventual relaxation Sustained Contraction (tetanic): • Combined individual twitches • Doesn’t relax • Rigor mortis
Diseases Myotonic Dystrophy—An Expanding Gene: • Stronger and more threatening with each generation • RNA too large to leave nucleas, gets copied, passed to next generation continuously • Weakness of limbs Hereditary Idiopathic Dilated Cardiomyopathy: • Actin not anchored to z-line properly • Causes the heart chambers to enlarge and eventually fail