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18 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Describe the heart's location |
•The heart lies obliquely in the mediastinum •Its base is directed anteriorly and slightly superiorly •Its apex is directed posteriorly and slightly inferiorly •Two-thirds of the heart's mass lies to the right of the midline in the sternum |
Oblique in mediastinum, base anterior>superior, apex posterior>inferior |
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The epicardium |
Is the visceral pericardium |
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The heart has a double layer of ____ with a layer of ____ in between |
Endocardium, Connective tissue |
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Which structure delivers blood to left atrium? |
Pulmonary veins |
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Valve located between left atrium and left ventricle |
Bicuspid (mitral) valve |
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What are Chordae tendinae? |
Strong connective tissue strings that are attached to papillary muscles and to the cusps of atrioventricular valves |
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What is the AV node? |
The group of modified cardiac muscle cells that delays action potentials between the atria and the atroventricular bundle |
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What is the SA node? |
The SA node is the heart's natural pacemaker. The SA node consists of a cluster of cells that are situated in the upper part of the wall of the right atrium (the right upper chamber of the heart). The electrical impulses are generated there. The SA node is also called the sinus node. |
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What will happen if the SA node stops functioning? |
The heart will stop functioning |
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What are action potentials? |
Changes in the electrical charge along the plasma membrane |
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What are gap junctions? |
Gap junctions are a specialized intercellular connection between a multitude of animal cell-types. They directly connect the cytoplasm of two cells, which allows various molecules, ions and electrical impulses to directly pass through a regulated gate between cells. |
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Importance of gap junctions? |
Action potentials pass rapidly from one cardiac muscle cell to another because of intercalated discs and gap junctions |
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What happens when voltage gated Na+ ion channels open? |
The depolarization phase of the cardiac muscle action potential occurs |
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When are voltage-gated K+ ions open? |
During the final repolarization phase |
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What is responsible for the depolarization phase (of the action potential)? |
The movement of the Na+ ions into the pacemaker cells |
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In an EKG, the P wave represents |
Depolarization of the atria |
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During the QT interval of the EKG_____? |
The atria contract and begin to relax |
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Somatic |
Consists of spinal and cranial nerves connected to skeletal muscles and skin reptors. These enable us to feel changes we can control |
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