| Term 
 | Definition 
 
        | the heart pumps and blood vessels allow circulation and delivery of neutrients and u2, o	Hollow cone shaped muscular organ within the thoracic cavity, o	14cm long by 9cm wide, o	lies under sternum, o	apex extends to the fifth intercostal |  | 
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        | outer layer made up of tough connective tissue |  | 
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        | middle layer that lines the fibrous pericardium |  | 
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        | Visceral pericardium (epicardium) |  | Definition 
 
        | layer that cover the heart ; at the base, the visceral pericardium folds back to form the parietal pericardium fluid in between layers is serious fluid |  | 
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        | Epicardium (visceral pericardium) |  | Definition 
 
        | outermost layer consisting of connective tissue, blood, and lymph capillaries |  | 
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        | middle layer consisting of cardiac muscles; thickest part |  | 
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 | Definition 
 
        | innermost layer consisting of connective tissue and is continuous with the endothelium (lining of blood vessels) of major vessels joining the heart; contain purkinje fiber (specialized cardiac muscles that act as nerve fibers to send impulses to the cardiac muscles) |  | 
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        | receives blood returning to the heart, thin walled |  | 
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        | pumps blood to the body (lungs and body) thicker walled cause they are sending blood further away |  | 
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        | divides the atria to the right and left |  | 
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 | Definition 
 
        | divides the ventricles into right and left |  | 
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        | 2 Atrioventricular valves (A-V valves) |  | Definition 
 
        | attach with chordae tendinae to prevent backflow of blood |  | 
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        | leads to the pulmonary trunk to lungs |  | 
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 | Definition 
 
        | rigid layer of connective tissue that surrounds the valves |  | 
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 | Definition 
 
        | leads to the aorta to feed the heart and body |  | 
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        | Term 
 
        | Path of the Blood through the Heart Step 1 |  | Definition 
 
        | Deoxygenated blood returns to the heart through the right atrium via the superior and inferior vena cave |  | 
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        | Term 
 
        | Path of the Blood through the Heart Step 2 |  | Definition 
 
        | Right atrium contracts to force blood through the tricuspid valve into the right ventricle |  | 
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        | Path of the Blood through the Heart Step 3 |  | Definition 
 
        | Right ventricle contracts to close the tricuspid vale and forces blood through the pulmonary valve into the pulmonary trunk |  | 
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        | Term 
 
        | Path of the Blood through the Heart Step 4 |  | Definition 
 
        | The pulmonary trunk diverges into 2 pulmonary arteries that carry blood the lungs where carbon dioxide within the blood  is exchanged with oxygen in the lungs |  | 
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        | Term 
 
        | Path of the Blood through the Heart Step 5 |  | Definition 
 
        | Freshly oxygenated blood returns to the heart through the left atrium via 4 	pulmonary veins |  | 
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        | Term 
 
        | Path of the Blood through the Heart Step 6 |  | Definition 
 
        | The left atrium contracts to force blood through the bicuspid valve into the left 	ventricle |  | 
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        | Term 
 
        | Path of the Blood through the Heart Step 7 |  | Definition 
 
        | Left ventricle contracts to close the bicuspid valve&forces through the aortic valve, blood enters aorta to feed heart and body |  | 
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 | Definition 
 
        | first branches of the aorta that carry blood to the heart |  | 
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        | drain blood from the heart muscles and carry it to the coronary sinus which empties into the right atrium |  | 
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        | artria contracting in unison |  | 
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        | ventricles contracting in unison |  | 
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        | brief moment when the entire heart relaxes |  | 
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        | = caused by vibrations in the tissues when blood velocity changes within the heart |  | 
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        | ventricular contraction and a-v valves close |  | 
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        | ventricular relaxation and semilunar valves close |  | 
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 | Definition 
 
        | Pressure within the chambers rises and falls with the contraction and relaxation of the atria and ventricles |  | 
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        | When the atria fill, the pressure within is greater than that of the ventricles and forces the A-V valves to open |  | 
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        | Pressure increases as the atria contracts to empty the remaining blood from the chambers |  | 
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        | When the ventricles begin to fill, the ventricles will contract and stimulate papillary muscles to contract |  | 
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 | Definition 
 
        | Once the papillary muscles contract, they will pull the chordae tendinae to close and prevent backflow of blood |  | 
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        | Term 
 
        | Cardiac Conduction System |  | Definition 
 
        | specialized cardiac muscles conducting impulses throughout the myoacrdium |  | 
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 | Definition 
 
        | mass of merging fibers that act as a unit, atrial syncytium & ventricular syncytium |  | 
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        | Cardiac Conduction System Step 1 |  | Definition 
 
        | Sinoatrial node (S-A node or pacemaker) = self-exciting mass of specialized cardiac muscles; generates the impulses for the heartbeat |  | 
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        | Cardiac Conduction System Step 2 |  | Definition 
 
        | Impulses spread to the atrial syncytium and causes it to contract |  | 
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        | Cardiac Conduction System Step 3 |  | Definition 
 
        | Impulses travels to the junctional fibers( small fibers that allow the atria to contract and empty fully before the impulse reaches the ventricles) leading to the Atrioventricular node (A-V node) |  | 
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        | Term 
 
        | Cardiac Conduction System Step 4 |  | Definition 
 
        | Branches of the A-V bundle give rise to Purkinje fibers that lead to the papillary muscles |  | 
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        | Cardiac Conduction System Step 5 |  | Definition 
 
        | Fibers stimulate papillary muscles contraction as ventricles contract |  | 
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        | Term 
 | Definition 
 
        | the pacemaker. Connected to both autonomic divisions of nervous(sympathetic and parasympathetic) - sympathetic speeds up the heart rate
 - parasympathetic slows down the heart rate
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 | Definition 
 
        | Cardiac control center of the medulla oblongata controls the 2 divisions Responses to barareceptors which detect changes in blood pressure
 Hypothalamus
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 | Definition 
 
        | the more you work the more your heart works to provide oxygen to body. So high activity causes heart activity to go up. |  | 
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        | Term 
 | Definition 
 
        | fluctuates, blood vessels dilate and constrict based on temp of body. Hot=dilation(blood flows out) cold=constrict(makes lumen smaller and causes more time for heart activity) |  | 
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        | Term 
 
        | Concentrations of certain ions |  | Definition 
 
        | Potassium – when high, there is a decrease in heart activity. If low there is an abnormal rhythm. Calcium – when levels are high there is an increase heart rate/long contractions. When levels are low there is a decrease in heart rate/short contractions
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        | Term 
 
        | Walls of the arteries and veins |  | Definition 
 
        | Tunica interna(endothelium), tunica media(smooth muscles), tunica externa(connective tissue) Have the ability to constrict or dilate
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 | Definition 
 
        | Arteries are strong and elastic vessels carrying high-pressure blood Arterioles are branches of the arteries, smaller, lead to capillaries
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 | Definition 
 
        | Smallest vessels, endothelium only, exchange site |  | 
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        | Exchanges in the capillaries |  | Definition 
 
        | - Substances are exchanged between the blood and tissue cells. - Capillary permeability varies from region to region.
 - Areas of greater metabolic activity have a greater density of capillaries.
 - Precapillary sphincters help to regulate the amount of blood entering the capillary bed and are controlled by oxygen concentration.
 - Blood entering capillaries contain high amounts of oxygen and nutrients that diffuse out the capillary and into tissues.
 - Hydrostatic pressure drives fluid and small molecules out the capillaries.
 - Osmotic pressure (venule end) causes tissue fluid to return to bloodstream.
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 | Definition 
 
        | venules lead from capillaries to form veins veins possess flap-like valves to prevent backflow
 thinner than arteries and carry low-pressure blood
 blood reservoir
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 | Definition 
 
        | force of blood against the arterial walls Arterial blood pressure rises and falls based on the cardiac cycle
 *Highest during ventricular contraction
 *Lowest during ventricular relaxation
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        | Term 
 
        | Factors; Cardiac Output(Heart Action) |  | Definition 
 
        | The amount of blood discharged per minute. When heart action goes up, blood pressure goes up. |  | 
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        | Term 
 | Definition 
 
        | based on body size, age, and gender. The volume goes up, the pressure goes up. Younger ppl have greater blood volume than older ppl. Larger ppl have larger body volume. |  | 
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        | Term 
 
        | Factors; Peripheral Resistance |  | Definition 
 
        | friction btwn the blood and the walls of the arteries. When it increases, there's more friction and causes a slower stream to cause slight backup. |  | 
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        | Term 
 | Definition 
 
        | the thicker of the blood the harder the blood flow, therefore blood pressure increases. |  | 
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 | Definition 
 
        | is a surge of blood with each of ventricular contraction. |  | 
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        | Regulations of blood pressure |  | Definition 
 
        | Blood pressure(BP)=COxPR Blood pressure is determined and regulated by Cardiac Output and Peripheral Resistance
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 | Definition 
 
        | cardiac output influenced by sympathetic and parasympathetic div. Emotional upset, exercise, temperature can effect cardiac output
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        | Term 
 | Definition 
 
        | vasomotor center of the medulla oblongata can adjust sympathetic impulses to regulate arteriole walls. Carbon Dioxide, oxygen, and hydrogen ions can also affect peripheral resistance
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 | Definition 
 
        | influenced by skeletal muscle contraction, breathing, and vasoconstriction of the veins. |  | 
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        | Term 
 | Definition 
 
        | vessels carrying blood to and from the lungs and the heart. - Includes pulmonary trunk, pulmonary arteries, lungs, alveolar capillaries in the lungs, pulmonary veins.
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 | Definition 
 
        | vessels carrying blood from the heart to the rest of the body and back. - Includes aorta and its branches leading to the body tissues and the venous system returning blood from the body to the right atrium.
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        | Term 
 | Definition 
 
        | -Principal branching of aorta Ascending aorta branches into coronary arteries
 Arotic arch branches into brachiocephalic, left common carotid, and left cubclavian arteries – head and upper limbs
 Descending aorta(thoracic aorta) gibes rise to arteries of the thoracic region.
 Abdominal aorta gives rise to arteries of the upper digestive tract and lower limbs.
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 | Definition 
 
        | alternate pathways through which blood can reach the brain. |  | 
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        | Term 
 | Definition 
 
        | - Returns blood to the heart after the exchange of substances between blood and tissue. - Run parallel with the arteries and are named accordingly
 - Veins from the head and upper torso drain into the inferior vena cava.
 - Veins from the heart drain into coronary sinus which then drains into the right atrium
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        | Term 
 
        | Hepatic Portal Circulation |  | Definition 
 
        | - Hepatic portal vein carries blood from the abdominal region to the liver in order to filter and detoxify blood, absorb nutrients, phagocytize bacteria. -Hepatic vein drains the liver and enters the inferior vena cava
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