Term
| What is the length of a sacromere? |
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Definition
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Term
| the connective tissue that surround individual muscle cells |
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Definition
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Term
| Organized bundles of myofilaments within each muscle fiber that are each surrounded by a sarcoplasmic reticulum |
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Definition
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Term
| What separates myofibrils? |
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Definition
| mitochondria and sacroplasmic reticulum |
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Term
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Definition
| Link thick filaments to M-line |
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Term
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Definition
| Extends into thick filaments from Z-lines. Flexibly stabilizes thick filament position |
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Term
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Definition
| caps thin filament, maintains length |
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Term
α-actinin &
CapZ (ß-actinin): |
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Definition
| Anchor & weave thin filaments into Z-line |
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Term
| Central T-tubule with 2 adjoining terminal cisternae. Located at A-I band junctions in human skeletal muscle |
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Definition
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Term
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Definition
| X-linked genetic disorder of membrane-associated protein, dystrophin |
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Term
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Definition
| Important component in a complex that stabilizes membrane structure, and forms a structural link between muscle fiber and surrounding basal lamina. |
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Term
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Definition
| decreases the amount of muscle development by blocking the development of satellite cells |
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Term
| Fiber diameter and muscle strength |
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Definition
| the larger the diameter the stronger the muscle fiber due to an increased number of proteins or satellite cells |
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Term
| Things that can cause muscle atrophy |
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Definition
Disuse
Cachexia- muscle gets smaller during cancer because the body begins to break down muscle proteins
Neurogenic-issue with the nerve stimulated the muscle |
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Term
| Things that can cause muscle hypertrophy |
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Definition
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Term
| Changes in band width seen during a muscle contraction |
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Definition
A-band: Constant
I-band: Narrows
H-band: Narrows
A-I overlap: Increases |
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Term
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Definition
Myosin head binds to binding site on actin
Conformational change in myosin hinge region drives power stroke
Fresh ATP binds to myosin head allowing release from actin.
(ATP hydrolysis “re-cocks” myosin head to “fire” next power stroke) |
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Term
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Definition
Toxin complex uptake by receptor-mediated endocytosis
Toxin light chain dissociates and enters cytosol where it cleaves components of the synaptic fusion complex
Prevents fusion of synaptic vesicles with presynaptic membrane and ACh release
Cleaves the SNARES so Ach vesiscle can not bind to the plasma membrane |
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Term
| Where can satellite cells be found? |
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Definition
| within the basal lamina of a muscle cell |
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Term
| A disorder characterized by autoantibodies to Ach receptors. Causing inflammation and widening of the synaptic cleft decreasing the surface area. THis leads to progressive loss of neuromuscular function |
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Definition
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Term
| How is the depolarization propogated down the T-tubule during excitation-contraction coupling? |
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Definition
| voltage gated ion channels |
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Term
| during the excitation-contraction coupling what releases calcium and then pumps the calcium back in after the depolarization? |
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Definition
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Term
| What are the 3 ways calcium is removed from the cytosol? |
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Definition
1. mitochondria
2. reuptake by SR CaATPase (SERCA)in SR membranes
3. sarcolemmal Na+/Ca+ exchange pumps (NCX) |
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Term
| A molecule that inhibits SERCA activity |
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Definition
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Term
| One axon and all the muscle fibers it innervates |
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Definition
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Term
| Why does damage to a single nerve rarely cause a complete loss of muscle function |
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Definition
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Term
| the size of the motor unit that is involved in gross and postural movments |
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Definition
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Term
| the size of a motor unit that is involved in fine movement |
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Definition
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Term
| receptors that monitor muscle tension (stretch). Modify contraction strength |
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Definition
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Term
| the difference between intrafusal and extrafusal muscles |
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Definition
intrafusal muscle are specialized muscles with sensory abilities.
extrafusal muscle is just normal muscle |
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Term
| A reflex that is sensed by the muscle spindles and is processed in the spinal cord |
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Definition
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Term
| A type of skeletal muscle involved in slow contraction, that is red due to an abundance of mitochondria, has a high level of oxidation and low glycolysis, scant amount of glycogen. Important for endurance. Example Postural muscles |
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Definition
type I skeletal muscles
Red Fiber |
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Term
| a type of skeletal muscle that have fast contractions, mostly white due to lower number of mitochondria, low levels of oxidation, but high levels glycolysis, and an abundant amount of glycogen. Quickly fatigued. burst activity. causes a buildup of lactic acid. example muscles of the eye, most of the limb muscles |
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Definition
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Term
| Enzyme histochemical staining for this structure marks the number of mitochondria in muscles. |
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Definition
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Term
| death by muscular dystrophy is usually due to |
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Definition
| respiratory failure or heart failure |
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Term
| a substance that competes with ach for its receptors |
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Definition
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Term
| an acetylcholinesterase inhibitor, that could be a treatment for myasthenia gravis |
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Definition
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Term
| a substance that blocks choline reuptake |
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Definition
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Term
| What are some tests used to diagnose myasthenia gravis? |
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Definition
1. Edrophonium test: related to a brief improvement of symptoms
2. Antibodies in the blood for Ach receptor |
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Term
| tension generated by stretching non-muscular elements within the whole muscle |
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Definition
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Term
| Tension generated by cross bridge cycling in contrile elements is transmitted to the load and movement occurs |
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Definition
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Term
| the weight or reciprocal force (resistance to movement) exerted by the object on the muscle |
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Definition
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Term
| what must be greater to move a load |
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Definition
| tension must be greater than the load |
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Term
| The two types of isotonic muscle tension |
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Definition
| concentric and eccetric contraction |
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Term
| muscle tension that remains constant as muscle changes length |
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Definition
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Term
| A type of isotonic contraction that involves muscle shortening |
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Definition
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Term
| a type of isotonic contraction that involves muscle lengthening |
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Definition
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Term
| tension that develops at constant muscle length. the tension prevents the muscle shortening |
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Definition
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Term
| A muscle fiber is restimulated before it has completely relaxed, and the second twitch is added to the first twitch |
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Definition
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Term
| If a muscle fiber is stimulated so rapidly that it does not have an opportunity to relax at all between stimuli, a maximal sustained contraction is known as |
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Definition
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Term
Increase availability of [Ca2+] as muscle work; muscle liberates
heat--> the enzyme system become more efficient. the reason why you should warm up before exercising |
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Definition
| Treppe (staircase effect) |
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Term
| maximal contraction is achieved when the muscle fiber is at its..... |
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Definition
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Term
| if the load = max force muscle can exert, velocity of shortening = 0 then.... |
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Definition
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Term
| Why is energy needed for muscle contraction |
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Definition
1. Perform cross-bridge cycling
2. Pump Ca2+ to the SR
3. Maintain Na+ and K+ concentration across muscle fiber membrane |
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Term
| the muscle fiber type is dependent on what... |
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Definition
| the nerve that innervates the muscle fiber |
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Term
| limited amount of energy source that is used in the first few seconds of exercise |
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Definition
| ATP and Creatine Phosphate |
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Term
| a type of metabolism where glycogen is broken down during heavy exercise and lactic acid is produced |
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Definition
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Term
| Nutrient breakdown with extra long exercise, cardiovascular and respiratory adjustments are made |
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Definition
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Term
| the balance between the energy required by the working muscle and the rate of ATP proction via aerobic metabolism |
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Definition
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Term
| THe lag between the onset of exercise and reaching the steady state of increase in oxygen consumption (ATP may come from anaerobic metabolism or other store sources; |
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Definition
O2 deficit
this decreases with training |
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Term
| The oxygen consumed in excess of the resting value during recovery from exercise. |
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Definition
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Term
| Ways a muscle can undergo hypertrophy. |
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Definition
1. Increase the amount of actin and myosin
2. adding sarcomeres at the end of the muscle |
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Term
| What causes rigor mortis? |
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Definition
a) Inability of the dying cells to exclude calcium
b) Calcium influx into muscle cells promotes binding of myosin cross bridges
c) No ATP available for cross bridge detachment
d) Actin and myosin become irreversibly cross-linked |
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Term
| Occurs as a defense mechanism in muscles in order to not deplete supplies of ATP |
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Definition
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Term
| Occurs when the CNS does not stimulate a neuron to contract a muscle. is pyschologically based |
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Definition
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Term
| How many calciums bind to TnC |
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Definition
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Term
presence of large amounts of muscle protein (myoglobin) in the urine.
• Results after major muscle trauma i.e. muscle crush injury.
• Long-distance running, certain severe infections, exposure to electrical shock can cause extensive muscle damage and excessive release of myoglobin.
• May cause renal failure if myoglobin is trapped in renal capillaries/tubules |
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Definition
| Rhabdomyolysis (myoglobinuria): |
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