Term
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Definition
- Size of a fist
- Pumps 1000 gallons of blood every day through blood vessels
- Hollow organ composed mainly of muscle tissue with a series of one-way valves
- Located in the chest cavity between the lungs in a region called the mediastinum
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Term
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Definition
- Three layers: pericardium, myocardium and endocardium
- Pericardium: 2layered serous membrane the covers entire structure; between the membranes is a serous fluid that allows friction-free movement
- Myocardium: forms the bulk of the heart wall and is the thickest and strongest layer; composed of cardiac muscle tissue; contraction is responsible for pumping blood
- Endocardium: innermost layer. composed of a thin layer of connective tissue; lines the interior of the heart, the valves and the larger vessels of the heart
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Term
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Definition
- Right Atrium: upper right chamber; receives deoxygenated blood from the body; superior vena cava returns blood from the head, neck and arms; inferior vena cava returns blood from lower body
- Right Ventricle: lower right chamber. it receives deoxygenated blood from the right atrium; pumps blood to the lungs via the pulmonary artery to release CO2 and receive oxygen
- Left atrium: upper left chamber; receives oxygenated blood from the lungs via the pulmonary veins
- left ventricle: lower left chamber; receives oxygenated blood from the left atrium; thickest most muscular section; pumps the oxygenated blood out through the aorta to all parts of the body
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Term
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Definition
- Tricuspid valve: Atrioventricular valve; located between the right atrium and the right ventricle; called tricuspid valve because it contains three flaps, or cusps;
- Bicuspid valve: AV valve; located between the left atrium and the left ventricle; commonly called the mitral valve;
- Pulmonary semilunar valve: located between the right ventricle and the pulmonary artery; has three cusps that resemble a half moon
- Aortic semilunar valve: located between the left ventricle and the aorta; has three cusps that resemble a half moon
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Term
Electrical Conduction System
Automaticity |
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Definition
| the heart muscle tissue's inherent ability to contract in a rhythmic pattern. |
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Term
Electrical Conduction System
Irritability |
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Definition
| Heart muscle cell's ability to respond to a stimulus in the same way that nerve cells do |
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Term
Electrical Conduction System
Sinoatrial (SA) Node
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Definition
| Location where heartbeat is initiated. AKA as a pacemaker. Impulses are passed to the AV node; AV node slows the impulses to allow the ventricles to fill |
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Term
Electrical Conduction System
Bundle of His
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Definition
| group of conduction fibers that receive impulses from the SA node; |
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Term
Electrical Conduction System
Right and Left branches of AV bundle |
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Definition
| small branches of fibers divided to the right and left branches of AV bundle; passes impulse to the purkinje fibers |
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Term
Electrical Conduction System
Purkinje fibers
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Definition
| branches of fibers that surround the ventricles; impulses travel rapidly through the ventricles and cause contractions which empty the ventricles |
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Term
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Definition
| complete heartbeat; the 2 atria contract while the two ventricles relax; when ventricles contract, the atria relax; comlete diastole and systole of both atria and ventricles constitute a cardiac cycle; takes an average of 0.8 second |
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Term
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Definition
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Term
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Definition
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Term
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Definition
| heart sounds produced by closure of the valves; the first sound, lubb, is heard when AV valves close; the second, dubb is heard when the semilunar valves close |
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Term
Blood Vessels
Capillaries |
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Definition
| tiny blood vessels joining arterioles and venules |
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Term
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Definition
| large vessels carrying blood away from the heart |
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Term
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Definition
| Vessels that convey blood from the capillaries and return to the heart |
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Term
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Definition
| blood vessels of the smallest branch of the arterial circulation; deliver the blood to the tissues. |
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Term
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Definition
| tiny veins that link with the larger veins and return to the heart |
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Term
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Definition
| the delivery of oxygen and nutrient-rich arterial blood to cardiac muscle tissue and the return of oxygen-poor blood from this active tissue to the venous system |
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Term
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Definition
| When blood is pumped from the left ventricle of the heart through all parts of the body and returns to the right atrium |
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Term
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Definition
| the largest artery (1 inch[2.5 cm] in diameter). When oxygenated blood leaves the left ventricle, it enters the aorta. the aorta is composed of 4 parts: te ascending aorta, the arch, the thoracic portion of the descending aorta, and the abdominal portion of the descending aorta |
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Term
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Definition
| largest vein; there are two, inferior and superior; returns blood from peripheral circulation to the right atrium of the heart |
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