| A | B |
|---|
| Functions of Muscle | Motion, movement of material in the body, thermoregulation, mainitaining posture, and regulating organ volume. |
| Characteristics of muscle tissue | Excitability, contractility, extensibility, and elasticity. |
| Excitability | Respond to stimulus |
| Contractility | Shorten its length |
| Extensibility | Extend or stretch |
| Elasticity | Return to original shape |
| Subdivisions of muscle | Muscle-Fasciculi-Muscle cells (fibers)-Myofibrils-Myofilaments |
| Connective Tissue | Epimysium, Perimysium, and Endomysium |
| Thin Myofilament | actin, tropomyosin, troponin |
| Thick Myofilament | myosin (cross-bridges) |
| Motor Neuron | Nerve cell that stimulates a muscle. |
| Neuromuscular junction | General area of "contact" between a motor nueron and a muscle cell. |
| Motor End Plate | Muscle membrane directly under end of motor neuron. |
| ACh (acetylcholine) receptors | Millions of ACh receptors are located on the motor end plates. |
| Acetycholine | Neurotransmitter secreted by motor neurons that transmits stimulus to motor end plate...ie. to muscle. |
| Motor unit | Motor neuron plus all the muscle cells (2-2000) it innervates. |
| Subliminal stimuli | (Subthreshold) weak stimulus, no contraction. |
| Liminal stimuli | (Threshold) a stimulus that is strong enough to cause a muscle cell to contract. |
| All or None Principle | Muscle Fiber will contract all it can or it will not contract at all. |
| Twitch | Rapid, single contraction resulting from a single stimulus. |
| Treppe | Later contractions are stronger. |
| Tetanic (COMPLETE TETANUS) | Rapid contractions, completely smooth myogram. |
| Tetanic (INCOMPLETE TETANUS) | Not so rapid contractions, incompletely smooth myogram. |
| Isotonic | Results in movement. |
| Tonic | Maintains muscle tone and posture.....a sustained partial contraction in response to stretch receptors. |
| Mucsle Waste Products | CO2, lactic acid, and heat. |
| Recovery Oxygen Consumption | The amount of Oxygen required after exercise to convert excess lactic acid into glycogen, to replenish ATP and creatine phosphate, and to replace the O2 removed from myoglobin. |
| Slow Oxidative Muscle Fibers | Contract slowly using aerobic processes, lots of capillaries, mitochondria, and myoglobin, very fatigue resistant, and used when maximum endurance is required. |
| Fatigue | Decreased strength of muscle contaction |
| Fibrosis | Formation of excess connective tissue |
| Muscular Dystrophy | Degeneration of muscle cells, usually only skeletal, most common form hereditary, absence of a gene that can make the muscle protein dystrophin. |
| Myasthenia Gravis | Autoimmune deactivation of neuromuscular junction |
| Spasm | Short duration...painless twitch of a single muscle |
| Cramp | Longer duration...painful tetanic contraction. |
| Convulsion | Violent contraction...whole groups of muscles |
| Fibrillation | Quivering...unsynchronized |
| Tic | Twitch(often of eyelid and facial muscles) typically psychological in origin |
| Gangrene | Tissue death from reduced blood supply. |
| Myosclerosis | Hardening of muscle |
| Shin Splints | inflammation of periosteum and/or flexor digitorum. Tendonitis of posterior tibialis muscle, or stress fracture of tibia. |
| Wryneck | Abnormal, continuous contraction of neck muscles. |
| Lever | A rigid rod that moves about on a fulcrum. ie. bones |
| Fulcrum | A fixed point on which a lever moves. ie. joints |
| Effort | A force applied to a lever to make the lever move. Effort results in a muscle contraction. |
| Resistance | Another force that acts upon a lever. |
| Prime Mover | The muscle primarily responsible for causing the desired movement. |
| Antagonist | Muscle that opposes the prime mover...must relax. |
| Synergist | Muscles that help the prime mover. |
| Fixators | Synergistic muscles that stabilize the origin of the prime mover. |
| Fusiform | Fascicles are almost parallel, but diverge at center of muscle. |
| Circular | Fascicles arranged in a circle, often forming a sphincter. |
| Unipennate | Fascicles are found only on one side of the tendon. |
| Bipennate | Fascicles are found on two sides of a centrally located tendon. |
| Multipennate | Fascicles attach from many directions to several tendons. |
| Origin | Attachment to stationary bone. |
| Insertion | Attachment to moveable bone. |
| Intradermal | Within the skin...allergy testing |
| Subcutaneous | Under the skin...insulin. |
| Intramuscular | Within a muscle |
| Intravenous | Within a vein, fast action. |
| Intraspinal | Within the subarachnoid space |
| Intraosseus | within a bone |
| Three most commonly used intramuscular injection sites | Gluteus medius, lateral thigh, and deltiod. |
| Tetanus | Caused by Clostridium Tetani-results in spastic paralysis-mechanism unclear, apparently causes central nervous system to stimulate muscles continuously. |
| Gas Gangrene | Caused by Clostridium perfringens-results in death of muscle-bacterial toxins affect muscle directly. |
| Botulism | Caused by Clostridium botulinum-results in flaccid paralysis-inhibits release of Acetycholine at motor neuron endings in neuromuscular junctions. |
| Force | Push or Pull. |
| Scalar quantity | No direction. |
| Vector quantity | Has direction. |
| Concurrent forces | 2 or more vectors applied to the same object at the same time. |
| Resultant Force | The overall force that results from the action of concurrent forces. |
| Torque | Twisting force...produces rotation. |
| Center of gravity | Balance point at which mass is "centered". |
