Term
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Definition
| Blood pumps: from the Heart to the Arteries, to the Arterioles, to the Capillaries, to the Venules, to the Veins, and eventually back to the heart. |
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Term
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Definition
| Blood flows through the Heart and travels out the right side and back through the left side. The Pulmonary Circuit eliminates Co2 by the Lungs, and oxygenates the blood. |
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Definition
| Blood flows through the body and delievers oxygen to the (deoxygenated) body cells & carries waste away. It travels out the left side of the heart and back through the right side. |
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Term
| Size & the Location of the Heart |
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Definition
| Average Size of the Heart is 14cm long and 9cm wide. It is located within the mediastinum, posterior to the sternum, medial to the lungs, anterior to the vertebral column, and lies upon the diaphragm. The top of the heart is called the Base and the bottom is called the Apex. |
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Term
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Definition
| Pericardium(Outer Layer) is made of dense Connective Tissue. The inner layer is the Serous. The Serous has two layers, the Outer Parietal Pericardium, and the Inner Visceral Pericardium. Serous fluid is located between the Pericardium Cavity. |
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Term
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Definition
| Outer Layer is called Epicardium. It is responsible for the secretion of Serous Fluid. The middle layer is called the Myocardium. It is the thickest layer and is composed of cardiac muscle. It also has the richest blood supply. The innermost layer is called the Endocardium. The Endocardium has blood vessels and is made of smooth muscle tissue. |
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Term
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Definition
| The heart has 4 Chambers, 2 Upper Atria, and 2 Lower Ventricles. The Atria receive blood returning to the Heart. The walls are extremely thin and separated by the Interatrial Septum. Auricles are found external to the Atria. The Ventricles are the lower half of the heart, and is where blood is sent out. It is separated by the Interventricular Septum. The right side Myocardium is much thinner than the left side |
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Term
| Atrial Natriuretic Peptide(ANP) |
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Definition
| Hormone secreted from Atria in response to increased stretching of the Heart. ANP inhibits the release of renin and aldosterone. This results in the excretion of sodium and water which lowers blood volume and blood pressure. |
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Term
| Heart Valves of the Right Side |
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Definition
| The Tricuspid(Right Atrioventricular) Valve separates the Atrium from the Ventricles. It is composed of three cusps and is held to the Papillary muscles by Chordae Tendinae. The second valve of the Heart on the right side is the Pulmonary(Semilunar) Valve. It leads from the right Ventricle to the Pulmonary Trunk. |
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Term
| Heart Valves of the Left Side |
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Definition
| The Mitral(Atrioventricular/Bicuspid) Valve is responsible for permitting blood flow from the left Atrium to the left Ventricle. It consists of 2 cusps and is held to the Papillary Muscles by Chordae Tendinae. The last valve is the Aortic(Semilunar) Valve. It leads from the left Ventricle into the Aorta. |
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Term
| Pathway of Blood through the Heart |
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Definition
1.)Blood from the Systemic Circuit
2.)Superior/Inferior Vena Cava
3.)Right Atrium-->Tricuspid Valve
4.)Right Ventricle-->Pulmonary Valve.
5.)Pulmonary Trunk
6.)Pulmonary Arteries
7.)Alveolar(Lung)Capillaries
8.)Pulmonary Veins
9.) Left Atrium--> Mitral Valve
10.)Left Ventricle--> Aortic Valve
11.)Aorta
12.) Blood, back to Systemic Circuit |
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Term
| Blood Supply to Heart Tissue |
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Definition
| Blood flows to the heart best through ventricular contraction. When blood is being supplied, it is best through ventricular relaxation. This is because the valves are closed and there is no blocking of the vessels. Blood travels from the coronary arteries & branches to the capillaries to the cardiac veins. The cardiac veins are parallel to the cardiac arteries. Cardiac veins drain into the coronary sinus and returns blood to the right atrium. |
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Term
| Angina Pectoris(Chest Pain) |
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Definition
| Occurs when a thrombus or embolus partially blocks coronary arteries. The myocardial cells then become deprived of oxygen. Pain normally occurs when the heart is being stressed(physically or emotionally). A complete clot can lead to myocardium tissue death and result in a myocardial infarction. |
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Term
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Definition
| Systole is heart contraction. Diastole is heart relaxation. The atria contracts together and the ventricles contract together. |
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Term
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Definition
| Is a series of events that constitute a complete heart beat. Blood moves between high and low pressures in each chamber which changes during the cardiac cycle. |
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Term
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Definition
| Atrial Systole. This means the AV Valves are open and only 30% of blood moves from the atria to the ventricles. |
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Term
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Definition
| Ventricle Systole and Atrial Diastole. The AV Valves become closed, and the SL Valves open. The Chordae Tendinae prevents the valves from bulging into the Atria too far. Blood the leaves the Ventricles and enters the Atria through the Veins. |
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Term
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Definition
| Ventricle Diastole. AV Valves Open and SL Valves close. 70% of blood moves from the Atria to the Ventricles. All 4 chambers become relaxed at this point at some point. There is also high pressure in the blood vessels but low pressure in the ventricles. |
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Term
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Definition
Lubb(Cardiac Cycle 2) happens during ventricular systole. What you hear is the AV Valves closing.
Dubb(Cardiac 3) Happens during ventricular diastole. What you hear is the closing of the SL Valves.
A Murmur is an abnormal sound of the valves not closing all the way |
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Term
| Cardiac Conduction System |
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Definition
| Clumps & Strands of specialized cardiac muscle that initiates and distributes impulses throughout the myocardium |
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Term
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Definition
SA Node; found on the superior wall of the right atrium. Initiates 80b/m. It is the "jumpstarter" of the heart
AV Node; found on the inferior wall of the right atrium. Delays impulses from the SA Node to allow the Atria to contract completely.
AV Bundle(Bundle of Hs); between ventricles
Purkinje Fibers; found on the outside of the ventricles. |
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Term
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Definition
| Muscles in the ventricular myocardium forms irregular patterns. This causes the ventricles to twist when contract to "wring" out the blood. Purkinje Fibers stimulate the Apex first in order to push blood up toward vessels |
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Term
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Definition
| Recording of the electrical changes that occur in the myocardium during the cardiac cycle. ECG's are used to asses the hearts ability to conduct impulses. Body fluids are used to conduct the current. ECGs diagram the following waves; PWAve; atrial depolarization(cardiac cycle 1), QRS Wave;ventricle systole(cardiac cycle 2), TWave, ventricular repolarization(cardiac cycle 3) |
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Term
| Electrocardiogram Imaging |
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Definition
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Term
| Regulation of the Cardiac Cycle |
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Definition
| Autonomic nerve impulses that alter the activities of the SA and AV nodes. Factors that influence heart rate: physical exercise, body temp, and the concentration of various ions. Potassium: electrical potential of membrane. Calcium: cardiac muscles depend on blood carried calcium. The parasympathetic impulses decrease heart rate. The sympathetic system increases heart rate. The cardiac center in the medulla regulates the autonomic impulses to the heart. |
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Term
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Definition
| Carry blood away from the heart. They are very thick and the middle layer is me of smooth muscle and elastic tissue. The outer layer is made of connective tissue. Arteries carry blood under relatively low pressure. Vasoconstriction & Vasodilation are controlled by sympathetic innervation |
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Term
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Definition
| Receive blood from the arteries and carry blood to the capillaries. made of smooth muscle tissue and a small amount of connective tissue |
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Term
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Definition
Where site of exchange occurs of substances between blood and body cells. Smallest diameter blood vessel, Semipermeable.
Sinusoids are leaky capillaries that occur in the liver or spleen, When this happens large proteins are able to pass through the membrane |
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Term
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Definition
| Much thinner than Arterioles. Receive blood from the capillaries |
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Term
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Definition
| Carry blood toward the Atrium. Walls are thinner than the arteries. There are three layers but the middle is very poorly developed. Some veins have flap like valves. Carries blood under relatively low pressure ad is a blood reservoir. |
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Term
| Regulation of Capillary Blood Flow |
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Definition
| More capillaries are in areas requiring more oxygen and nutrients. Precapillary Sphincters(bands) may close a capillary, respond to needs of a cell, low oxygen & nutrients cause sphincter to relax. |
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Term
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Definition
| pressure is greatest in arteries |
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