Term
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Definition
| voluntary, striated muscle that is used to create movement |
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Term
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Definition
| highly vascularized, and highly innervated (nerves near blood vessels) |
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Term
| From small to large muscle (skeletal) |
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Definition
| Actin & Myosin--> Myofilament--> Myofibril--> muscle fiber-->fascicle and -->muscle |
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Term
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Definition
H - only myosin
A - myosin and actin
I - only actin |
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Term
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Definition
composed of myosin, occupy the centtral portions of the sarcomere,
Titin - anchor the thick filament to the Z line -->stabilizes myosin druing contraction
C-,X-, and H-proteins are positioned around the thick filaments |
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Term
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Definition
I bands are thin filaments only, are attached to the Z line
Actin is capped by CapZ protein on + end & thin filament stabilized y alpha-actinin on the Z line |
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Term
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Definition
I bands are thin filaments only, are attached to the Z line
Actin is capped by CapZ protein on + end & thin filament stabilized y alpha-actinin on the Z line |
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Term
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Definition
filament = bundle of myosin dimers
head of the myosin molecules has Actin binding and ATPase domains
ATP-drives the mov. of myosin heas along actin
Myosin II- has a double head and tail |
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Term
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Definition
binds myosin heads
the filament is polar and contains myosin-binding sites on the G-actin monomers |
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Term
| Myosin-Actin interactions |
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Definition
| Ca2+ binds to troponin C and makes troponin I move out of the way and allow troponin T to bind to tropomyosin and this allows the troponin-tropomyosin complex to move out of the way and allow myosin to bind to G-actin |
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Term
| Myosin cross bridge cycle |
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Definition
| ADP comes off and ATP binds + head releases and pivots--> ATP is hydroplyzed--> ADP and Pi stay bound to head as weakly attached to actin--> head binds to Actin and as Pi is released--> Powerstroke, myosin head pivots--> ADP comes off and ATP binds a binds--> head releases and pivots |
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Term
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Definition
| Terminal cisterna and T tuble (invagination of the sarcolemma) - which make contact with the sarcoplasmic reticulum- allows action potential to be brought quickly into the muscle |
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Term
| Excitation-Contraction coupling |
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Definition
| AP--> reaches T-tublar system --> changes conformation of L-type Ca2+ channel to open and increase concentration of intracellular Ca2+ this changes the conformation of the R-type Ca2+ channel and releases stores from the sarcoplasmic reticulum--> bind to troponin C and initiates contraction--> A ca2+ ATPase pum, pums the Ca2+ back into the SR and this Ca2+ binds to calsequestrin |
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Term
| Myofibril connection to the membrane |
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Definition
Intermediate filament (Desmin) - extends from one myofibril to the other and anchored to the sarcolemma, encircle the Z disk of each sarcomere
Plectin links adjacent desmin filaments to each other
alph-Beta-christallin - is a heat shock protein associated with desmin, protects it from stress-induced damage |
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Term
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Definition
involuntary striated muscle that pumps blood throughout the body
arrangement of sarcomeres and a T tubule system associated with the SR near the Z line |
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Term
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Definition
Involuntary non-striated muscle for visceral organ contraction/function
found on the walls of bladder, Gi, Respiratory tract, blood vessels, etc |
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Term
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Definition
fibers are joined together by junctional complexes (intercalated disks) and have gap junctions
single, centrally placed nuclus
branched muscle fibers
mitochondria are more abundant |
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Term
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Definition
thin filaments insert into dense bodies (like Z disks of striated muscle)
gap junctions electrically couple smooth muscle
Contain actin and myosin, but filaments are not arranged in orderly arrays as in skeletal muscle (limited SR) |
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Term
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Definition
| vesicles at the periphery of smooth muscle cells. work like T tubules, increasing the surface area for transfer of calcium into the cytoplasm |
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Term
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Definition
| in cross-section- nuclei of smooth muscle are found in the center, with very little cytoplasm around the nucleus |
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Term
| Dense bodies of Smooth muscle |
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Definition
| function as the actin filament binding sites (or Z bands). |
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Term
| Smooth Muscle Contraction |
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Definition
| Ca2+ binds to calmodulin-->which binds to Myosin Light Chain Kinase (activates it)--> phosphorylates Myosin light chains--> bind to F-actin and "walk" along the filament |
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Term
| Differences between skeletal, cardiac, and smooth |
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Definition
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Term
| Duchenne Muscular Dystrophy |
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Definition
muscle degenerates/regenerate
loss of the diaphragm is usually the cause of death |
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Term
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Definition
mutation in dystrophin gene
dystrophin is associated with F-actin and it functions to reinforce and stabilize the sarcolemma during the stress of muscle contraction by maintaining a link between the cytoskeleton and the EM |
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Term
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Definition
| necrotic (dead tissue) cardiocytes are completely surrounded by neutrophil then scar tissue develops |
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Term
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Definition
| aerobic exercise requires oxygen and uses a higher percentage of slow-twitch (type I) muscle fibers |
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Term
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Definition
are used for anaerobic exercise (sprinting) uses a higher percentae of fast-twitch muscle fibers
anaerobic exercise can cause type II hypertrophy |
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Term
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Definition
decreased lean body mass during aging due to loss of skeletal muscle mass
overall leads to decreased muscle strength placing patients at risk ofor falls
increase in slow twitch (type I) and decrease in fast twitch (type II) |
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