Term
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Definition
Inherent rhythmicity
Can contract spontaneously |
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Term
|
Definition
Sinoatrial node
Atrioventricular node |
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Term
| Conductive fibers of the heart |
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Definition
Bundle of His
Purkinje fibers |
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Term
| what is the flow of the impulse through the heart |
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Definition
starts with the SA node, goes to the AV node
at the AV node the impulse is delayed as these fibers are slower then the rest
AV node through the bundle of His(AV bundle) splitting into R and L bundles
impulse to the ventricle through purkinje fibers |
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Term
|
Definition
Long, branching, anastomosing fibers
Arranged in layers |
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Term
| cardiac muscle nucleus shape |
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Definition
Central oval nucleus
Occasionally bi-nucleate |
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Term
| cardiac muscle Cell junctions form |
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Definition
|
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Term
| 2 types of intercalcated disks |
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Definition
| Specialized end-to-end junctions can be transverse or lateral |
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Term
| Transverse intercalated disks functions |
|
Definition
Mechanical junctions
Fascia adherens
Thin filaments attach
Can act as Z disks
Desomsome |
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Term
| Lateral intercalated disks functions |
|
Definition
Electrical connections
Gap junctions |
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Term
| what is found inside of a cardiac muscle cell |
|
Definition
½ Volume Mitochondria
Glycogen stores
Abundant myoglobin |
|
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Term
| what % of energy do cardiac muscles get from triglycerides |
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Definition
|
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Term
| these atrial muscle cells help control blood pressure |
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Definition
| Atrial Natriuretic Peptide |
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Term
| Atrial Natriuretic Peptide are what type of cell |
|
Definition
| APUD or diffuse endocrine ceclls |
|
|
Term
| what is the function of Atrial Natriuretic Peptide |
|
Definition
Lowers blood pressure
Decreases ability of renal tubes to resorb water and sodium |
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Term
| what structures differ between cardiac muscle and skeletal muscle? |
|
Definition
Sarcoplasmic reticulum
T-Tubules
Ca++
Ion channels
Duration of action potential |
|
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Term
| what are the differences in the sarcoplasmic reticulum of cardiac muscle compared to skeletal muscle |
|
Definition
Less extensive
Insufficient stored Ca for contraction
No dialated terminal cisternae
Small terminal nears T-tubule |
|
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Term
| these make up the cardiac muscle diad |
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Definition
| the T-Tubule is only intimately associated with ONE Terminal cisternae |
|
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Term
| where is the diad located? |
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Definition
|
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Term
| how big is the T-tubule in cardiac muscle compared to in skeletal muscle |
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Definition
|
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Term
|
Definition
| 2 terminal cisternae + T-tubule |
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Term
| how does contraction in cardiac muscle differ from contractions in skeletal muscle |
|
Definition
Ca comes in through the plasma membrane opening Ca channels in the SR
it takes Ca from both of these sources for the muscle to fire |
|
|
Term
| what does DHPR do in cardiac muscle? |
|
Definition
| DHPR isoform establishes coupling mode |
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Term
|
Definition
No Striations
Fusiform (spindle-like, tapered) |
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Term
|
Definition
| Single Nucleus (centrally located) |
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Term
|
Definition
|
|
Term
|
Definition
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Term
| Multiunit smooth muscle cell traits (2) |
|
Definition
Contract independently
Unique (own) nerve supply |
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|
Term
| Unitary smooth muscle cell traits (4) |
|
Definition
Most common
Do NOT contract independently
Gap Junctions between contiguous cells
Nerve supply shared |
|
|
Term
| what are the functions of smooth muscle |
|
Definition
| contraction and protein synthesis |
|
|
Term
| what proteins do smooth muscles make? |
|
Definition
collagen
elastin
glycosaminoglycans
proteoglycans
growth factors |
|
|
Term
| smooth muscle arrangement |
|
Definition
| laid out in sheets-Usually 2 layers perpendicular, for peristalsis |
|
|
Term
| what are smooth muscle thin filaments made of? |
|
Definition
Actin and caldesmon, Tropomyosin
No troponin |
|
|
Term
| caldesmon function smooth muscle |
|
Definition
| (protein that blocks the active site of F-actin) |
|
|
Term
| what acts as Z-disks in smooth muscle? |
|
Definition
| dense bodies act as Z-disks |
|
|
Term
| where are the heavy heads located in smooth muscle? |
|
Definition
| located the whole length of the fiber |
|
|
Term
| what is on the two ends of the smooth muscle cell |
|
Definition
| they do not have heads like striated muscle does |
|
|
Term
| smooth luscle surface area differs from striated muscle in this way and for this reason |
|
Definition
| larger surface area for the interaction of actin with myosin II and permitting contractions of long duration. |
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Term
| Unitary smooth muscle Intermediate Filaments composition |
|
Definition
|
|
Term
| Multiunit smooth muscle Intermediate Filaments compostiion |
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Definition
|
|
Term
| along with thin filaments , intermediate filaments create this |
|
Definition
|
|
Term
| these act as the sarcomere between dense bodies |
|
Definition
| Interwoven array of thin, thick and intermediate filaments |
|
|
Term
| Dense body to dense body= |
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Definition
|
|
Term
| what happens to the nucleus when smooth muscle contracts? |
|
Definition
|
|
Term
| how is smooth muscle contraction controlled? |
|
Definition
Control different than striated muscle
Absence of troponin |
|
|
Term
| actin-binding site is masked by this |
|
Definition
|
|
Term
|
Definition
| small plasma membrane invaginations act similar to T tubules |
|
|
Term
| Calcium ions from caveolae and SR do this |
|
Definition
|
|
Term
| the binding of calmodulin in smooth muscle does this |
|
Definition
| binds to caldesmon unmasking active site on actin |
|
|
Term
| what 2 things does Ca do in smooth muscle contraction? |
|
Definition
Calcium ions from caveolae and SR bind to calmodulin
Ca2+-calmodulin complex activates myosin light chain kinase |
|
|
Term
| the Ca calmodulin complex activates this |
|
Definition
Myosin light chain kinase phosphorylates one of the myosin light chains
Unfolds light meromyosin moiety |
|
|
Term
| when the smooth muscle cell unfolds, unmasking the actin binding site this happens |
|
Definition
interaction between actin and myosin
Results in contraction |
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