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15 Cards in this Set
- Front
- Back
Cardiac muscles fibers are small, ___ cells and has ___. Adjacent fibers are connected at their ends by junctions (dark zigzagged line) called ____ Each fiber has a oval euchromatic nucleus in the __ of the cell. |
branched striations intercalated disc center |
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What are the similarites of cardiac muscles and skeletal muscles? Are the organelles less developed in cardiac muscles? what is the main difference? |
1)both have contractile filaments (actin and myosin), myofibrils, and sacromeres with A, I bands, and Z lines and 2) membranous specializations that include sarcoplasmic reticulum with terminal cisternae and tubules -yes -Cardiac muscle has a Diad (one t tubule and one cisternae at the Z line |
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(T or f) Cardiac muscles are abundant with myoglobin and mitochondria ( t or F) individuals are not attached to each other with special junctions |
true false (they are by intercalated discs) |
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___ and ____ hold adjacent cells together and transmit the force of contraction from cell to cell ____ anchors actin filament of the last sarcomere to the sarcolemma ___ are strong spot attachments that bind neighboring cells. ___ allow the diffusion if ions and electrical excitation between the cells
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fascia adherens (type of intermediate junction) and desosomes fascia adherens desosomes gap junctions |
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The linking of the individual cells structurally and ionically, allow the cell to contract together as a mass or ____ Cardiac muscles are ____ that is they exhibit a spontaneous rhythmic contraction. (t or f) there are motor end plates in the cardiac muscle |
synctium autogenic false |
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Purkinje fibers are located in the ___ of the heart. they contain an abundant amount of __ with a few myofibrils. They are specialized to a play a key role in coordinating ___ of the heart. they help set the pace of the contraction by quickly conducting and spreading waves of ____ to other cardiac muscle by gap junctions |
endocardium glycogen the pattern of contraction excitation |
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Do cardiac muscles replicate? If portions of the cardiac muscle dies (myocardial infarct) muscle tissue is replaced by what? |
no CT |
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hypertension can lead to ___ off the cardiac muscle if the increased functional demands on the heart to maintain the high blood pressure leads to a massive increase in cell and heart heart size |
hypertrophy |
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Where is smooth muscle commonly found? Smooth have __ spindle shaped cells Each fiber has how many central nucleus? Are there any striations? |
in the walls of tubes (blood vessels, airways) and hollow organs (gut, uterus) acidophilic one no |
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(True or false) myofilamets are present and is organized into myofibrils, sarcomeres, a and I bands in smooth muscle In smooth muscle, the filaments interconnect and are anchored to ___ that in turn are anchored to the sarcolemma |
false, they are not dense bodies
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Do smooth muscles cells have specialized membrane system (organelles)? they have small invaginations called ___ , and ___ are prevalent in the cytoplasm
Are there any specialized motor end plates in smooth muscle? what are they often linked by? |
No caveolae pinocytotic vesicles no gap junctions |
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(T or f) Most of the smooth muscle tissue can spontaneously contract, although the autonomic nervous system and hormones of the endocrine system can modify the rate of contraction |
true |
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Smooth muscle can undergo __ and ___
*smooth muscle divide to maintain its number, new smooth muscle can develop from existing smooth muscle cells, or undifferentiated stem cells or from pericytes associated with blood vessels* |
hyperplasia, hypertrophy |
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Can smooth muscle proliferation and extracellular matrix (fibers and proteogylcans) deposition play an important role in the formation of atherosclerosis lesions in the walls of blood vessels? |
yes |
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___ are malignant tumors derived from smooth muscles. they are most found in the pelvic organs (especially the uterus) and blood vessels. These rare tumors usually occur in adults __ are malignant tumors that resemble developing skeletal muscle cells. they usually occur in the arms and legs. this rare tumor is typically present in children (1 through 6) |
Leiomysarcomas Rhabdomyosarcomas |