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9 Cards in this Set
- Front
- Back
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Where is the heart located? |
-mediastinum and is enclosed by the pericardial cavity -in the thoracic cavity medial to the lungs |
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What is muscle found in the heart and description of this muscle |
- cardiac muscle- Only in heart Striated Needs oxygen Contains Intercalated discs which are branching interconnections between cells Specialized intercellular connections |
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List the three layers of the heart and be able to describe each layer |
1. Serous Pericardium—Made up of 2 layers: a. Parietal pericardium is outer layer b. Visceral serous- pericardium that is the sac directly touching heart . Epicardium is another name 2. Myocardium—middle layer. It is a concentric layers of cardiac muscle. Pumping action 3. Endocardium—innermost layer |
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Know the cardiac cycle |
1. Cardiac cycle begins—all four chambers are relaxed 2. Atrial Systole -Atrial systole (100 msec)—atria contract; finish filling ventricles -Atrial diastole (270 msec)—continues until start of next cardiac cycle (through ventricular systole) 3. Ventricular Systole -Isovolumetric contraction (called this because no volume change). Contracting ventricles push AV valves closed but not enough pressure to open semilunar valves. Increasing pressure opens semilunar valves. -ventricular systole = second phase. This allows blood to leave the ventricle, ejection 4. Ventricular Diastole -Ventricular diastole—early. Ventricles relax and their pressure drops. The blood in aorta and pulmonary trunk backflows. This leads to a reflex closure of the semilunar valves -Isovolumetric relaxation. All valves closed. No volume change. However, blood passively filling atria -Ventricular diastole—late. All chambers relaxed. AV valves open. The ventricles fill passively to ~70% |
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two atrioventricular valves and the semilunar valve. |
AV Valves: tricuspid ( right atrium and ventricle) and bicuspid or mitral ( left atrium and ventricle) Semilunar valves: pulmonary valve which allows one way back flow from right ventricle to pulmonary trunk and the aortic valve which allows one way back flow from left ventricle to the aorta |
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systole and diastole |
Systole- contraction; blood leaving chamber
Diastole- relaxation; chambers refilling |
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layers of blood vessels? |
1. Tunica intima, • This is the innermost layer • Is lined with endothelial cells with connective tissue with elastic fibers – In arteries
2. Tunica media lamina). It separates the tunica interna from the tunica interna. • Is the middle layer • Contains concentric sheets of smooth muscle – We need this layer to control the diameter of the blood vessels. o Contraction causes vasoconstriction o Relaxation causes vasodilation 3. Tunica externa, or tunica adventitia • This is the outermost layer • This is made up of a connective tissue sheath – In arteries, contains collagen and scattered elastic fibers – In veins, this layer is generally thicker than the tunica media. |
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different types of capillaries? |
Continuous Capillary- Endothelium is a complete lining
Fenestrated Capillary- Contains “windows,” or pores within the endothelial lining |
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What do veins have the keep the blood flowing in this vessel |
Valves- permit blood flow in one direction and prevent backflow of blood toward capillaries |
