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61 Cards in this Set
- Front
- Back
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Functions of the Skeletal system |
Locomotion Facial expression Posture Body position Regulation of temperatureorigin |
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Origin |
The place where the Muscle stars on a bone; stationary |
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Insertion |
The place where the muscle ends on the bone |
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Muscle Action |
The insertion moves towards the origin (bicep curls) |
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Reverse Muscle Action |
When the insertion is anchored, the origin can move towards the insertion (pull ups) |
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First Class Levers |
E^ F L_ Scissors Neck and maxilla |
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Second Class Levers |
F L_ E^ Wheel barrow Going on reléve |
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Third Class Levers |
F E^ L_ Tweezers Elbow joint |
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Abduction of the arm |
Agonist: deltoid Antagonist: latissimus dorsi Synergist: supraspinatus Fixator: trapezius |
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Flexion of the Forearm |
Agonist: brachialis Antagonist: triceps Branchii Synergist: biceps Branchii Fixator: pectoralis major |
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Organization of Muscle |
Groups of muscle (deep fascia) Muscle (epimysium) Fascicles (perimysium) Myofibril (endomysium) |
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Major Structures of a Muscle Fiber |
Sarcolemna: conduction of electrical signals SR: control of muscle contraction/ calcium storage Myrofibrils: contraction via sacromeres |
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Sacromere |
Z-discs: define length h-zone: only thick filament M-line: down the middle A band: all thick filament I band: only thin filament ZOO: overlap Titin filament: pulls apart during relaxation |
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Thin filament |
Actin: myosin binding site Troponin: holds tropomyosin in place, moves when Ca binds Tropomyosin: covers myosin binding site on actin |
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Thick filament |
Myosin: motor protein, form crossbridges with actin |
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Sliding Filament Mechanism |
Myosin heads form cross bridges, conformational change energized ATP hydrolysis causes power strokes and think filaments slide over thick |
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Contraction cycle (1) |
Myosin binding sites on actin are exposed when Ca binds to troponin |
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Contraction cycle (2) |
Myosin heads form crossbridges |
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Contraction cycle (3) |
Myosin heads pivot towards the center of the sacromere |
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Contraction cycle (4) |
ATP binds to myosin Head, and detaches the from actin |
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Contraction cycle (5) |
ATP hydrolysis and the energy released re-energized the myosin head back to cocked position |
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Contraction cycle (6) |
Repeats until myosin binding site on actin is no longer available |
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Rigor of Death |
Lack of ATP to detach myosin Head from actin |
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Components of NMJ |
Motor Nueron Synaptic end bulb Voltage gated calcium channel Acetylcholine vessels Synaptic cleft Acetylcholine receptors Motor end plate Sodium T-tubule SR Calcium |
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NMJ (1) |
Action potential arrives at synaptic end bulb and voltage gated calcium channels open |
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NMJ (2) |
Synaptic vessels with acetylcholine go through exocytosis |
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NMJ (3) |
Acetylcholine is released into synaptic cleft and binds to receptors in the motor end plate of sarcolemna |
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NMJ (4) |
Acetylcholine receptors opens and allow sodium to enter the muscle fiber, generating action potential on the sarcolemna |
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NMJ (5) |
Acetylcholine beaks Down into acetylcholine esterase |
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Acetylcholine Esterase |
East remaining acetylcholine in synaptic cleft so that another muscle action potential does not arise unless more acetylcholine is released from the motor neuron |
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Role of Calcium |
Calcium diffuses into sarcoplasmic and myofibrils where it can bind to troponin and initiate contraction |
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Order of muscle contraction |
1 excitation: motor neuron sends signal to sodium influx 2 contraction coupling: action potential on sarcolemna to release of calcium from SR 3 contraction: calcium bind to troponin to detachment of crossbridge 4 relaxation: AP stops to sacromere to resting position |
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Creatine Phosphate Pool |
Fastest way to create ATP ~ 15 sec sustainability |
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Glycogen (anaerobic) |
Glycolysis Creates pyruvate acid and lactic acid Occurs in cytoplasm ~ 2 min of sustainability |
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Glycogen (aerobic) |
Cellular respiration with amino acids, fatty acids, pyruvic acid, oxygen Mitochondria Slow process ~ 40 min (to several hours) sustainability |
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Fatigue |
Progressive increase in the effort required to maintain a desired force, and progressive inability to maintain this force in sustained or repetitive contractions |
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Causes of Fatigue |
Glycogen depletion Lactic acid buildup from anaerobic glycolysis Phosphate build up from creation phosphate metabolism |
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Most Common Fatigue |
Psychological Nervous Muscular |
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Cori Cycle |
Muscle creates lactic acid through anaerobic glycolysis Lactic acid is turned into glucose in the liver Glucose returns to muscle |
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O2 Debt |
Excess post exercise oxygen consumption Caused by: Cori cycle, resynthesis of creatine, replace oxygen with myoglobin, repair |
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Twitch |
Arising from a single electrical stimulus |
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Twitch sequence |
Latent period: 2 msec, no change in tension Contraction period: 10-100 msec, peak tension Relaxation period: 10-100 msec, tension decreases |
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Temporal Summation (tetanus) |
Increasing frequency of electrical stimulus to increase tension |
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Motor unit |
A motor neuron and all the muscle fibers it innervates |
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Special Summation |
Motor unit recruitment to increase tension |
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Size Principal |
Small fibers are used first and large ones are used last |
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Isometric |
Same length |
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Isometruc |
Same tension; after tension is generated length can change |
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Concentric contraction |
Effort > load |
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Eccentric Contraction |
Load > effort |
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Nervous Strategies to Increase Tension |
1) temporal Summation 2) spatial Summation |
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Controlled Strategies to increase force |
Optimal fiber length at he beginning of contraction. Tension generated is proportional to the number of crossbridges formed. Peak tension is developed by utilizing intermediate fibers |
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Slow Oxidative fibers |
Smaller Slowly contracting Aerobic metabolism |
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Fast Glycolytic |
Rapidly contracting Anaerobic M |
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Oxidative-Glycolutic Fibers |
Medium in size Relatively fast Primarily anaerobic |
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Hypertrophy |
With training, each muscle fiber increases in diameter because it increases the amount of myofibrils |
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Atrophy |
Decreased diameter due to decreased myofibrils but amount of nuclei stay the same |
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Muscle Adaptations |
Increased capillary action Increased mitochondria Increased cross sectional area |
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Cardiac Muscle |
Pumps blood Smaller branched cells Organized into sacromeres Longer contraction than skeletal No sufficient Ca from SR Extracellular SR Pacemaker cells No motor units No temporal summation |
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Smooth Muscle |
No sacromeres Crossbridges form Contraction is very slow Cytoplasmic Ca binds to calmodulin, myosin light chain kinase, myosin Head group stimulates |
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Structural proteins |
Titin: spans half the sacromere from z-disc to m line, stabilizes thick filament Dystrophin: cytoskeleton protein that links thin filaments to sarcolemna Nebulin: spans the length of thin filament, anchors thin filament to z disc Alpha-actin: found in z disc, binds to actin molecules Myomesin: found in m-line, binds to titin and thick filaments to connect them together |
