Term
| Endothelium is a lining of what types of cells? |
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Definition
| Simple squamous epithelium |
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Term
| The cardiovascular system is lined by what? |
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Definition
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Term
| What are the three layers/tunics of the heart? |
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Definition
| Endocardium, myocardium, epicardium |
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Term
| Endocardium is continuous with what? |
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Definition
| Tunica intima of vessels entering the heart |
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Term
| Myocardium is composed of what? |
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Definition
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Term
| How is myocardial cardiac muscle arranged? |
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Definition
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Term
| What is the name of the simple squamous epithelium covering the epicardium? |
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Definition
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Term
| What is the outer tunic of the heart wall? |
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Definition
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Term
| What cells are responsible for the contractility of the myocardium? |
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Definition
| Myocytes (cardiac muscle cells) |
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Term
| A centrally-located nucleus, lipofuschin granules near the nucleus, and poorly developed t tubles describes what cells? |
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Definition
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Term
| Mitochondria in ventricular myocytes are found where? |
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Definition
| Adjacent to the sarcolemma between myofibrils |
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Term
| How do t tubles of cardiac muscle cells compare to those of skeletal muscle? |
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Definition
| Much larger in diameter, less extensive |
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Term
| SR terminal cisterna and an apposed t tubule associate to form what? |
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Definition
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Term
| Cardiac muscle diads occur where? |
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Definition
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Term
| Junctional complexes at the ends of cardiac myocytes used for cell to cell attachment and ionic coupling are known as what? |
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Definition
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Term
| Intercalated discs are one of the most distinctive histological features of cardiac myocytes and sometimes appear as what? |
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Definition
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Term
| Intercalated discs possess what important specializations? |
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Definition
| Fascia adherens, desmosomes, gap junctions |
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Term
| What is the attachment site for actin filaments of terminal sarcomeres of cardiac myocytes? |
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Definition
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Term
| What is located in the transverse portion of a cardiac myocyte Z-disc? |
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Definition
| Fascia adherens, desmosomes |
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Term
| What is located on lateral portions of a cardiac myocyte Z-disc? |
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Definition
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Term
| What is responsible for physically holding myocyte ends together? |
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Definition
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Term
| What protein hexamer forms gap junctions between cardiac myocytes? |
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Definition
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Term
| What is largely responsible for the wave of contraction that spreads throughout the heart wall? |
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Definition
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Term
| Depolarization of a cardyac myocyte sarcolemma is carried to the next myocyte via ion flow through what? |
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Definition
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Term
| Ay any given depth, all myocytes of that layer run in what direction? |
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Definition
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Term
| Multiple layers of cardiac myocytes insert into what? |
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Definition
| Fibrous skeleton of the heart |
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Term
| The twisting and lifting motion of ventricular contraction is a functional result of what? |
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Definition
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Term
| How are myocyte layers oriented? |
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Definition
| Angled to adjacent layers |
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Term
| What are the different segments of the fibrous skeleton of the heart? |
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Definition
| Annuli fibrosi, trigonum fibrosum, septum membranaceum |
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Term
| What portion of the fibrous skeleton of the heart is found surounding the bases of the aorta, pulmonary artery, and atrioventricular orifices? |
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Definition
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Term
| What segment of the fibrous skeleton of the heart is found near the aortic valve cusp? |
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Definition
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Term
| What segment of the fibrous skeleton of the heart is found in the upper portion of the atrioventricular septum? |
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Definition
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Term
| What structural discontinuity between atrial and ventricular muscles ensures that the contraction of atria and ventricles will not occur simultaneously? |
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Definition
| Fibrous skeleton of the heart |
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Term
| Cardiac valves attach to what? |
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Definition
| Fibrous skeleton of the heart |
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Term
| Where is the Sinoatrial (SA) node located? |
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Definition
| Right atrium near junction iwth the superior vena cava |
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Term
| What is the site of initiation of excitation, also referred to as the pacemaker of the heart? |
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Definition
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Term
| Both the SA node and purkinje fibers lack what common feature of cardiac myocytes? |
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Definition
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Term
| What is the average rate of spontaneous depolarization by the SA node? |
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Definition
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Term
| What is comprised of cells that carry impulses from the SA node to the AV node? |
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Definition
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Term
| Where is the atrioventricular (AV) node located? |
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Definition
| Lower right side of the interatrial septum |
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Term
| What gives rise to left and right bundle branches that send conduction impulses into the unspecialized myocardium of the ventricles? |
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Definition
| AV bundle (bundle of His) |
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Term
| Which node conducts impulses relatively slowly, contributeing to the necessary delay between atrial and ventircular filling? |
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Definition
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Term
| What myocardial fibers are specialized for rapid impulse conduction? |
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Definition
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Term
| What connects cells of Purkinje fibers? |
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Definition
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Term
| True or false: Purkinje fibers are developmentally related to Purkinje cells of the cerebellum. |
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Definition
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Term
| Depolarization of the myocyte membrane opens what voltage gated channels? |
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Definition
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Term
| What induces Ca++ release from the SR of cardiac muscle? |
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Definition
| Voltage gated Ca++ channels |
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Term
| What accounts for most of the Ca++ that binds to TnC, initiating actin-myosin interaction? |
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Definition
| Ca++-induced Ca++-release response triggered at diads |
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Term
| What removes Ca++ from the sarcoplasm in cardiac muscle? |
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Definition
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Term
| What removes Ca++ that has entered the cell during cardiac muscle excitation? |
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Definition
| Na+/Ca++ exchanger protein |
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Term
| Where is the Na+/Ca++ exchanger protein that pumps Ca++ out of cardiac muscle cells located? |
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Definition
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Term
| What is the ratio of exchange in Na+/Ca++ exchanger proteins? |
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Definition
| One Ca++ out, three Na+ in |
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