Term
| Properties of muscle fibers or myofibers |
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Definition
-contract and generate force
-stretch when an opposing muscle contracts
-return to their original length after stretching - that is, they are elastic
-contact when stimulated by a neuron. |
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Term
| Skeleton muscle contains: |
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Definition
Nerves
Blood vessels
Connective tissue
Muscle cells (= myofibers). |
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Term
| Properties of muscle cells |
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Definition
-Bundled into fascicles
-Packed with myofibrils
-Contain thick and thin myofilaments (filaments)
-Consist of a number of different proteins involved in the process of of contraction. |
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Term
| Connective Tissues in Muscle |
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Definition
-Endomysium
-Perimysium
-Epimysium |
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Term
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Definition
| Delicate networks of connective tissue that surrounded and fill the spaces between individual muscle fibers (myofibers) |
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Term
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Definition
| Stronger connective tissue that ensheaths the fascicles, which are bundles of muscle fibers |
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Term
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Definition
Ensheaths the whole muscle. It is continuous with perimysium and also with connective tissue layers in the body called
"fascia", a loose term that describes collections of connective tissue large enough to be observed with the naked eye. |
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Term
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Definition
| Tendon, when the connective tissue elements extend as a broad flat layer |
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Term
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Definition
| is a large aponeurosis that caps the skull and is connected to the occipital and frontal belly of the epicranius muscle and also to the temporoparietalis muscles (the muscles draw back or tighten the scalp, raise the eyebrows, wrinkle the forehead, raise the ears) |
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Term
| Tendon or Synovial sheaths |
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Definition
Certain tendons, especially those of the wrists and ankles, that are enclosed by tubes of fibrous connective tissue
- permit tendons to slide back and forth |
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Term
| Muscle sarcoplasm contains: |
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Definition
-Mitochondria, to provide ATP.
-Sarcoplasmic reticulum - A network of membranous channels equivalent to the endoplasmic reticulum in other cells. Together with the T-tubules, with which it is closely associated, the sarcoplasmic plays an important role in excitation-contraction couping.
-Myofibrils |
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Term
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Definition
| The contracting element of skeletal and cardiac muscle. Myofibrils consist of repeating assemblies of protein myofilaments. |
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Term
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Definition
| An elongated molecule with two globular heads that can hydrolyze ATP and bind to actin. |
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Term
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Definition
| Composes the thin filaments. One end of an actin molecule is attached to a Z-line, that extends across the muscle fiber. |
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Term
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Definition
Each skeletal muscle fiber is connected to the axon of a motor neuron, the body of which is located in the spinal cord or a nucleus in the brain.
(One muscle fiber receives commands from only one motor neuron, but that one motor neuron may connect with (and send commands) many muscle fibers.) |
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Term
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Definition
| A motor neuron together with all the muscle fibers its connected to |
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Term
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Definition
| The junction of an axon with a muscle fiber |
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Term
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Definition
| At neuromuscular junction, the sarcolemma is modified to form a motor end plate. |
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Term
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Definition
-On arrival of an electrical action potential at the end of the nerve axon, a chemical transmitter called acetylcholine is released.
-Acetylcholine is just one example of a large class of substances called neurotransmitter. |
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Term
| Acetylcholine receptor molecule |
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Definition
| The acetylcholine molecules then bind to specific acetylcholine receptor molecules in the sarcolemma of the motor end plate. |
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Term
| Electrical depolarization |
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Definition
| Action potential that spreads oner the sarcolemma and causes the muscle fiber to contact |
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Term
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Definition
| Enzyme that hydrolyzes acetylcholine |
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Term
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Definition
| A poison that blocks neuromuscular transmission by binding to acetylcholine receptors. |
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Term
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Definition
-Prevents the release of acetylcholine.
-It is one of the most potent toxins known.
-in very small and controlled doses, it has been used clinically in the relief of muscle spasms. |
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Term
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Definition
| is an uncommon autoimmune disease. Patient develops antibodies against acetylcholine receptors in the neuromascular junction. |
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Term
| Nerve gases (Saran, Soman, Tabun) |
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Definition
| block acetylcholinesterase-increase AcCH, causing constant stimulation of muscles |
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Term
| Black widow venom (latrotoxin) |
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Definition
| explosive release of AcCh |
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Term
| Myosin interaction with actin, powerd by ATP |
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Definition
1) Resting condition, the myosin is primed and ready for action
2) Attachment of myosin head to actin
3) Power stroke
4) Detachment and reorientation
5) Preparation and priming for next attachment step |
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Term
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Definition
| Hydrolosis of ATP to ADP and an inorganic phosphate group. ATP binds to the mysin head in the detachment and reorientation step. In the resting, primened condition, this ATP has been hydrolyzed and products ADP and P remain bound to the myosin head. |
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Term
| Excitation-contraction Coupling |
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Definition
| Muscle contaction is initiated by a rise in intracellular calcium ions, mediated by the two actin associated proteins troponin and tropomyosin. |
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Term
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Definition
| the coupling of the nerve impulse with muscle contraction hinges around the release of calcium ions that are stored within the sarcoplasmic reticulum |
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Term
| Excitation-contraction STEP 1 |
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Definition
| The action of acetylcholine at the neuromasular junction causes a wave of electrical depolarization to spread over the surface of the sarcolemma and penetrate inot the interior of the muscle fiber via the T-tubule system. |
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Term
| Excitation-contraction STEP 2 |
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Definition
| The depolarization of the T-tubule membrane causes the sarcoplasmic reticulum to release a large amount of calcium ions into the sarcoplasm through calcium-release channels |
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Term
| Excitation-contraction Step 3 |
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Definition
| The result is a sharp rise in the concentration of calcium ions in the sarcoplasm. |
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Term
| Exctitation-contraction Step 4 |
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Definition
| The action of calcium is mediated by two proteins: Tropomyosin and Troponin |
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Term
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Definition
| Winds over the surface of the actin filament, and obstructs the binding of myosin to actin in the resting muscle. |
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Term
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Definition
| binds to actin and to tropomyosin. it also binds calcium ions. |
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Term
| Excitation-contraction Step 5 |
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Definition
| When the calcium ion concertration in the sarcoplasm rises sharply, it bind to toponin, which then causes a change in the topomyosin molecule so that it no longer hinders the binding of myosin to actin |
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Term
| Excitation in Cardiac Muscle |
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Definition
Large amounts of calcium ions enter the muscle cells through the T-tubule membranes. This calcium then acts to trigger release of more calcium ions from the sarcoplasmic reticulum.
The contation of cardiac muscle, therefore, is mucho more dependent on calium ions in the external medium than the contraction of skeletal muscle. |
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Term
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Definition
| An ATP-driben calcium pump in the membranes of the sarcoplasmic reticulum removes the calcium ions from the sarcoplasm back into the interior of the sarcoplasmic reticulum, where much of it bind to a protein called calsequestrin. |
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Term
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Definition
| after death a person's ability to make ATP is ended. Calcium leaks into the muscle-fiber and the muscle contracts. The muscle cannot relax because ATP in not available to detach the myosin from actin. |
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Term
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Definition
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Term
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Definition
| is a giant protein expressed in cardiac and skeletal muscle that spans half of the sarcomere from the Z-line to M-line. |
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Term
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Definition
| another giant muscle. Its molecule has one end at Z-line and the other at the end of the thin filament. Nebulin is is not found in cardiac muscle. |
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Term
| Desmin and the microtubules |
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Definition
| Maintain the structural order within the cell and connect the cytoplasm and all cellular organelles with the sarcolemma |
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Term
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Definition
| Links the intracellular structural components with those of the extracellular matrix. |
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Term
| The energy during exercise is derived from: |
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Definition
1) ATP already in the muscle cell (enough for 3 seconds activity)
2) Creatine phosphate (also known as phosphocreatine: adds energy for another 5-7 seconds activity)
3)glycolysis (an anaerobic process)
4) Krebs cycle
5) oxidative phosphorylation (aerobic) |
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Term
Creatine phosphate
(phosphagen system) |
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Definition
pool of energy stored in the cell. The enzyme creatine phosphkinase transfers the high-energy phosphate group of creatine phosphate to ADP, so generating more ATP for immediate use. This is known as the phosphagen system.
creatine phosphate + ADP ----> cretine + ATP |
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Term
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Definition
| Over 95% of total creatine is found in skeleton muscle. Meat and fish are dietary sources of creatine, which can also be synthesized in the body from the amino acids arginine, glycine, and methionine. useless for endurance |
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Term
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Definition
| Creatine phosphate is the major source of energy during the 8-10 seconds of 100-meter sprint. After that time, however, the muscles beome dependent on cellular metabolism as a source of energy for synthesizing more ATP. |
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Term
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Definition
| Oxygen for oxidative phosphorylation is provided by hemoglobin in the blood. |
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Term
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Definition
| Acts as a store for oxygen in the muscle and also facilitates oxygen diffusion to the mitochondria. |
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Term
100-meter dash
jumping
weight lifting
diving
football dashes |
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Definition
| Phosphagen system (creatine) |
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Term
200-meter dash
baseball home run
ice hockey dashes |
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Definition
| Phosphagen and anaerobic systems |
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Term
400-meter dash
100-meter swim
tennis |
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Definition
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Term
800-meter run
200-meter swim
1500-meter skating
boxing
2000 meter rowing, 1 mile rum |
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Definition
| Anaerobic and aerobic systems |
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Term
10,00-meter skating
cross-country skiing
marathon rum
jogging |
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Definition
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Term
| Excess Post-Exercise Oxygen Consumption Pays off the Oxygen Debt Built up During Exercise |
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Definition
a) Convert the accumulated lactate back to glucose in the liver. The glucose is used to replenish the glycogen stores of the liver and muscle. The cycle of glucose-pyrucate-lctate-glucose is sometimes called the Cori cycle.
b) Replenish the muscle ATP and creatine phosphate stores
c)Replenish the oxygen content of the muscle myoglobin. |
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Term
| Slow, Oxidative (Red) Fibers (Type 1) |
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Definition
| Endurance fibers - they generate aerobic energy and are relatively fatigue resistant. Red fibers look red because they contain the red protein myoglobin, a good supply of blood containing hemoglobin, and the red cytochromes in their many mitochondria. These fibers are important for utilizing fatty acids as well as glucose. |
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Term
| Fast, Glycolytic (White) Fibers (Type II) |
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Definition
| Carry our rapid, forceful movements-they generate anaerobic and are susceptible to fatigue. |
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