Term
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Definition
| individual muscles cell (2 other names) |
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Term
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Definition
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Term
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Definition
| plasma membrane/plasmalemma of muscle |
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Term
| skeletal, smooth, cardiac -> mesoderm |
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Definition
| list the 3 types of muscle, what germ layer are they derived from? |
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Term
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Definition
| muscle type responsible for movement of the skeleton, under voluntary motor control |
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Term
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Definition
| how much of the body mass is skeletal muscle? |
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Term
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Definition
| skeletal muscle fibers all exhibit ______________ response, either contracts or it doesn't |
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Term
| total # of fibers contracting at any given time (referred to as graded response) |
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Definition
| determines the strength of overall contraction of skeletal muscle |
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Term
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Definition
| group of muscle fibers supplied by a single motor neuron |
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Term
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Definition
| excitation of a motor unit results in contraction of ___ muscle fibers within that unit |
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Term
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Definition
| increase in the number of motor units firing within a muscle |
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Term
| 80-100 um, up to 35cm long |
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Definition
| size of individual skeletal muscle fibers |
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Term
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Definition
| cells of skeletal muscle are multinucleate and form ______ due to fusion of myoblasts into a multinucleate _____ during development |
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Term
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Definition
| synthesizes contractile proteins which assemble into sarcomeres |
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Term
| the periphery, lose ability to peripherate |
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Definition
| where do the nuclei of skeltal muscle cells migrate? |
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Term
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Definition
| CT that surrounds individual muscle fibers |
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Term
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Definition
| several (skeletal) muscle fibers bound together |
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Term
| perimyseum (connective tissue) |
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Definition
| surrounds fascicles of skeletal muscle |
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Term
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Definition
| surrounds an entire muscle, it is continuous with the tendonous attachment |
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Term
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Definition
| deep to superficial, what is the order of perimyseum, epimyseum, endomyseum? |
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Term
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Definition
| blood vessels and nerves follow what for support |
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Term
| slow twitch and fast twitch |
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Definition
| 2 types of fibers in skeletal muscle |
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Term
| early in development of myotubes |
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Definition
| when are fast/slow twitch muscles innervated by fast/slow nerves? |
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Term
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Definition
| what contractile proteins differ in slow/fast twitch muscles? |
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Term
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Definition
| what are type 1 muscle fibers? |
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Term
| slow twitch muscles(type 1) |
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Definition
| small muscle fibers with a lot of myoglobin, primarily use aerobic respiration for oxidative metabolism |
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Term
| type 1, slow twitch fibers |
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Definition
| muscle type common in peripheral limbs because it is resistant to fatigue, but only generates a moderate amount of muscle tension |
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Term
| type 2 (fast twitch fibers) |
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Definition
| muscle fiber type with large fibers, less myoglobin, fewer mitochondira |
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Term
| fast twitch skeletal muscle |
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Definition
| what type of fibers are type 2 fibers? |
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Term
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Definition
| this type of fiber uses primarily ANaerobic glycolysis for energy production |
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Term
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Definition
| this muscle fiber type has more mitochondria |
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Term
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Definition
| this type of muscle fiber has extensive sarcoplasmic reticulum for rapid Ca release |
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Term
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Definition
| this muscle fiber fatigues quickly, but generates high muscle tension for short bursts of activity |
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Term
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Definition
| what are the intermediate muscle fibers? |
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Term
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Definition
| during peak periods of exertion, both type 1 and 2 muscle fibers metabolyze ______ via anaerobic glycolysis to produce ATP |
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Term
| intermediate metabolites(of anaerobic glycolysis) such as lactic acid |
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Definition
| what precipitates as crystals in muscles, tearing muscle fibers, causing pain after heavy exertion |
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Term
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Definition
| what leads to ischemia, cramps, and cell death if it is severe enough |
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Term
| acute rhambdomyolysis and subsequent kidney failure (myoglobinuric nephrosis) |
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Definition
| what can extreme muscle exertion cause? |
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Term
| type 1 muscle fibers, and release of myoglobin |
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Definition
| what is broken down/released when acute rhambdomyolysis and subsequent kidney failure (myoglobinuric nephrosis) happens? |
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Term
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Definition
| increase in muscle cell size with exercise |
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Term
splitting/branching of individual muscle fibers, increase in mitochondria, and increase in volume of contractile proteins
rare: production of new muscle fibers |
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Definition
| causes muscle hypertrophy with exercise |
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Term
| atrophy, or possible denervation leading to atrophy |
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Definition
| with disuse-due to immobilization(from a splint or cast), muscles decrease in cell size causing this |
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Term
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Definition
| with increase in age, there is a progresssive loss of muscle fibers that causes a decrease in number and mass of muscle fibers |
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Term
| the extent of repair is limited, but primarily satellite cells proliferate following injury and differentiate into myoblasts |
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Definition
| when skeletal muscle is injured, how does it regenerate |
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Term
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Definition
| small myogenic cells adjacent to the sarcolemma that proliferate following injury |
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Term
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Definition
| another name for mechanoreceptors |
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Term
| neuromuscular spindles and neurotendinous spindles |
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Definition
| name the 2 types of mechanoreceptors found in muscle |
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Term
| muscle spindles/neuromuscular spindles |
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Definition
| intrafusal fibers located within the belly of muscles sensitive to changes in length |
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Term
| neurotendinous spindles/golgi tendon organs |
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Definition
| intrafusal fibers located within tendons, sensitive to changes in tension |
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Term
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Definition
| what are neurotendinous spindles/golgi tendon organs sensitive to? |
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Term
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Definition
| what are muscle spindles/neuromuscular spindles sensitive to? |
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Term
| mechanoreceptors (both types) |
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Definition
| prevent overstretching and tearing of muscles used in postural reflexes, coordination |
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Term
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Definition
| individual M fibers are composed of ___ |
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Term
| myofilaments/contractile proteins |
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Definition
| myofibrils are composed of numerous _____ in parallel bundles |
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Term
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Definition
| the 2 types of myofilaments |
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Term
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Definition
| thin filament, 6-8 nm in diameter |
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Term
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Definition
| thick filament, 15 nm in diameter |
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Term
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Definition
| ratio of myosin:actin in skeletal muscle |
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Term
| parallel arrangement of contractile proteins (actin and myosin overlap) |
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Definition
| causes striated appearance of (striated)muscles in longitudinal section |
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Term
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Definition
| myofibrils are arraned in ______, the functional units of muscle cells |
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Term
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Definition
| anchoring points for actin myofibrils |
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Term
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Definition
| what bands to actin and myosin overlap? |
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Term
| sarcomeres shorten, myofibrils stay the same length |
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Definition
| what shortens in muscle contraction, what stays the same length? |
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Term
| rratchet-like/ walk-along mechanism |
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Definition
| mechanism in sliding filament theory of muscle contraction |
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Term
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Definition
| what is required for thick and thin filaments to slide across one another(muscle shortening)? |
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Term
| shortening of the sarcomere via repeated binding of actin and myosin filaments (requires ATP) |
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Definition
| what creates the sliding filament motion? |
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Term
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Definition
| sites where skeletal muscle is innervated by motor neurons |
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Term
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Definition
| dilated terminal portion of the axon surrounded by myelin, rests on sarcolemma |
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Term
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Definition
| how are terminal boutons related to motor end plates? |
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Term
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Definition
| space between motor end plate of neuron and sarcolemma of muscle |
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Term
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Definition
| this chemical neurotransmitter usually bridges neuromuscular junctions |
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Term
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Definition
| how is the external lamina/muscle cell membrane arranged at the synaptic cleft? |
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Term
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Definition
| when an neuron is stimulated, what ion rushes into the neuron? |
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Term
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Definition
| what is released from the neuron once sodium channels open, allowing sodium to rush in? |
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Term
| the sarcolemma is depolarized and sodium rushes into the muscle fiber (causing release of Calcium from ER) |
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Definition
| when receptor proteins(neurotransmitters) bind to the sarcolemma what happens? |
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Term
| t-tubules (transverse tubules) continuous with the sarcolemma |
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Definition
| where the wave of depolarization travels in muscle fibers |
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Term
| extracellular space to ER and intracellular environment |
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Definition
| what do t-tubles link indirectly? |
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Term
| ends of t-tubules bounded by enlarged terminal cisternae of ER on either side |
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Definition
| forms a triad in a muscle fiber |
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Term
| sarcoplasmic reticulum and terminal cisternae |
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Definition
| when the muscle is relaxed this acts as a calcium reservoir |
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Term
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Definition
| this activates sliding filament mechanism leading to contraction |
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Term
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Definition
| causes conformational change in [myosin head & sliding of myosin past actin] troponin and tropomyosin (bound to actin) exposing the myosin-binding site on the actin filament |
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Term
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Definition
| myosin heads repeatedly bind and unbind in presence of ____ causing contraction |
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Term
1. myosin cross bridge attaches to the actin myofilament (myosin head in high energy conformation)
2. working stroke-the myosin head pivots and bends as it pulls on the actin filament sliding it toward the M line (ADP and Pi released)
3. as new ATP attaches to the myosin head, the cross bridge detaches (myosin head in low energy conformation)
4. as ATP is split into ADP and Pi, cocking of the myosin head occurs |
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Definition
| steps of sliding filament mechanism |
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Term
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Definition
| rhythmic wave-like contractions independent of neurological stimulation |
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Term
| highly irregular, branching fascicles (specialized for prolonged contractions with low force) |
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Definition
| how are smooth muscle fibers bound together? |
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Term
| smaller than skeletal muscles (2-5 um, and 2-200 um in length) |
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Definition
| size of smooth muscle fibers |
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Term
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Definition
| where is/are the nucle(i/us) in smooth muscles? |
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Term
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Definition
| ratio or actin to myosin in smooth muscle |
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Term
| no, it is not arranged into sarcomeres |
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Definition
| is smooth muscle striated? |
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Term
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Definition
| intracytoplasmic structures functionally equivalent to Z-discs provide attachment sites for actin in smooth muscle |
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Term
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Definition
| _____ complex that controls myosin binding |
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Term
| troponin, has calmodulin instead |
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Definition
| smooth muscle lacks _____ complex that controls myosin binding, instead has ______ |
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Term
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Definition
| in smooth muscles this binds calcium and activates myosin cross-binding |
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Term
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Definition
| what does smooth muscle have instead of T tubules/sarcoplasmic reticulum? |
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Term
| diffusion of extracellular Ca |
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Definition
| where does smooth muscle get Ca for contraction? |
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Term
| sympathetic and parasympathetic |
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Definition
| most smooth muscle has dual _____ and ______ innervation making it involuntary |
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Term
| ANS, hormones, local metabolites |
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Definition
| what smooth muscle contraction(calcium uptake) is influenced by |
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Term
sympathetic = inhibitory
parasympathetic = stimulatory |
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Definition
_______ stimulation -> inhibitory while
_______ stimulation is stimulatory to smooth muscles |
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Term
| single unit (tonic smooth muscle) |
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Definition
| smooth muscles fibers that contract as a unit, ex visceral smooth muscle of gut |
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Term
| multi unit (phase smooth muscle) |
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Definition
smooth muscle fibers that contract individual muscle fibers independently
ex: ciliary body of iris, erector pili musc. |
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Term
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Definition
| most common type of smooth muscle |
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Term
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Definition
| this type of muscle retains its ability to divide and repair itself following injury |
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Term
| endothelial cells, pericytes of blood vessels, & fibroblasts |
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Definition
| what cells can smooth muscle cells develop from? |
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Term
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Definition
| glandular epithelial cells can differentiate into |
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Term
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Definition
| fibrous CT sac surrounding the heart |
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Term
| serous, epicardium, mesothelial cells |
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Definition
| cardiac muscle has an outer fibrous CT tissue layer and an inner ____ layer continuous with ______ containing ___ cells |
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Term
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Definition
| lubrication containsed within pericardium |
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Term
| epicardium, myocardium, endocardium |
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Definition
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Term
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Definition
| type of mesothelium that is on the external surface of the heart |
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Term
| underlying fibroblastic CT and adipose tissue |
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Definition
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Term
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Definition
| layer of heart where blood vessels and nerves are located |
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Term
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Definition
| there is a protective layer of ____ surrounding the heart |
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Term
| thinner in atria, thicker in ventricles |
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Definition
| myocardium is _____ in the atria and _____ in the ventricles |
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Term
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Definition
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Term
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Definition
| myocardium contains bundles of myocytes attached to thick, ______ CT skeleton |
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Term
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Definition
| lines atria, and ventricles, covers heart valves |
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Term
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Definition
| type of endothelium in the heart (endocardium) |
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Term
| subendothelial fibroblastic CT interspersed with reticular fibers and smooth muscle |
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Definition
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Term
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Definition
| thicker in atria than ventricles due to greater turbulence in atria |
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Term
thicker-endocardium
thinner-myocardium |
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Definition
| what is thick in the atria, what is thinner in the atria? |
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Term
| within subepi and endocardial layers |
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Definition
| where are purkinje fibers located in the heart? |
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Term
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Definition
| the heart fibrous CT skeleton is composed of ___ and ____ |
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Term
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Definition
| tough fibrous rings at the base of the aorta and pulmonary arteries (AV valves) extending into the IVS |
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Term
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Definition
| tissue ossifies to form bony rings at the base of the AV valves to form this |
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Term
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Definition
| cardiac valves contain layer of fibrous tissue called _____ ___ covered with endothelium |
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Term
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Definition
| intermediate between smooth and skeletal muscle structurally and functionally |
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Term
| 1, central (ocassionally 2) |
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Definition
| how many nuclei cardiac muscle cells have and the location |
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Term
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Definition
| cardiac fibers are striated but under _____ control |
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Term
| diad, 1, 1 (skeletal muscle has 2 cisternae & 1 t-tubule) |
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Definition
| instead of a triad, cardiac contractile proteins have and intracellular ____ composed of _(#) T-tubules and __(#) cisterna of ER located at the _____ |
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Term
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Definition
| inherent automaticity is exhibited by individual ____ ____ |
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Term
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Definition
| M fibers of cardiac muscle cells branch, but the ends abut at specialized ____ unique to cardiac muscles-a specialized connection between cells |
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Term
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Definition
| enhance spread of contractile stimulus between cardiac mm cells and allow synchronous contractions |
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Term
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Definition
| provides attachment sites for myofibrils between adjacent cardiac mm cells |
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Term
| desmosomes, fascia adherens, gap junctions |
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Definition
| cell junctions that make up intercalated discs |
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Term
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Definition
| bind individual myocytes together laterally and on ends |
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Term
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Definition
| join ENDS of M fibers, like zonula adherens |
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Term
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Definition
| located laterally, provide ionic communication between cells, synchronize contractions and allow muscle to behave as a syncitium |
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Term
| sa node, av node, bundle of his, purkinje fibers |
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Definition
| components of cardiac conduction |
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Term
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Definition
| sa node, av node, bundle of his, and purkinje fibers consist of highly modified cardiac myocytes that coordinate conduction, joined by extensive ______ |
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Term
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Definition
| cardiac conduction cells are _____ that surrounding cardiac muscle cells and conduct impulses ____ faster |
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Term
| paler, due to glycogen content |
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Definition
| conduction cells in cardiac tissue stain _____ due to ______ content |
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Term
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Definition
| pacemaker, located at the junction of the superior vena cava and RA |
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Term
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Definition
| generates impulses that induce contraction of atria |
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Term
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Definition
| as impulses travel across atria, they stimulate the ____ (located between RA and V) |
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Term
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Definition
| delays the impulse giving atria time to contract |
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Term
| interventricular septa (IVS) |
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Definition
| after impulses cross the atria they travel down what structure |
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Term
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Definition
| this structure branches into L and R AV bundles within the IVS |
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Term
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Definition
| initiates ventricular contraction |
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Term
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Definition
| when bundle of his fibers subdivide in ventricular myocardium they ramify into ___ within the endocardium and spicardium of ventricular free wall |
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Term
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Definition
| what do purkinje fibers gradually merge with |
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Term
| sympathetic ganglia, increases |
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Definition
| sympathetic stimulation originates from ____ and ___ heart rate |
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Term
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Definition
| parasympathetic stimulation originates from ____ and ___ heart rate |
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