ch 7 - The Cardiovascular System Flashcards Preview

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Flashcards in ch 7 - The Cardiovascular System Deck (61)
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pathway of blood

deoxygenated blood into R atrium (past tricuspid valve) to right ventricle past pulmonary valve to pulmonary artery to lungs to be oxygenated to pulmonary veins to left atrium past mitral valve to left ventricle past aortic valve to aorta to arteries to arterioles to capillaries (systemic body) to venules to veins to venae cavae to right atrium (which is deoxygenated blood)


pulmonary circulation

first pump of heart, deoxygenated blood from body enters lungs from R side of heart


systemic circulation

second pump of heart; receives oxygenated blood from lungs into L side and pumps it to body through aorta


atrioventricular valves

atria are separated from ventricles by these


semilunar valves

separate atrioventricular valves and vasculature; allow creation of pressure within the ventricles necessary to propel blood forward and prevent backflow


tricuspid valve

valve between the right atrium and right venticle


tricuspid or mitral valve

valve between the left atrium and left ventricle


pulmonary valve

valve that separates right ventricle from pulmonary circulation


aortic valve

valve that separates left ventricle from aorta


pathway of electrical impulse in the heart

sinoatrial (SA) node, the atrioventricular (AV) node, the bundle of His (AV bundle) and its branches, and the Pukinje fibers


SA node

small collection of cells located in the wall of the right atrium; sight of impulse initiation in heart; generates 60-100 signals per minute w/o requiring neurological input. depolarization wave spreads from SA node, causes two atria to contract simultaneously resulting in an atrial kick (extra bit of blood forced into the ventricles through atrial systole (contraction) - accounts for 5-30% of cardiac output)


AV node

group of cells at junction of the atria and ventricles where electrical signal goes after SA node. Signal is delayed here to allow for ventricles to fill completely before they contract


bundle of His and branches

in electrical signal pathway of heart after AV node; embedded in interventricular septum (wall)


Purkinje fibers

last step in electrical signal pathway of heart; distribute the signal through the ventricular muscle


intercalated discs

connects ventricular muscle; contain many gap junctions directly connecting cytoplasm of adjacent cells allowing for coordinated ventricular contraction


vagus nerve

provides parasympathetic signals to slow hr



ventricular contraction and closure of the AV valves occurs and blood is pumped out of the ventricles



heart is relaxed, seminlunar valves are closed and blood from the atria fills the ventricles


Cardiac output

total blood volume pumped by a ventricle in a minute; CO = HR x SV (stroke volume, volume of blood pumped per beat); CO should = about 5 L per min


endothelial cells

line all blood vessels; help to maintain vessel by releasing chemicals that aid in vasodilation and vasoconstriction; can allow WBCs to pass through the vessel wall and into the tissues during an inflammatory response; also release certain chemicals when damaged that are necessary for formation of blood clots to repair vessel


only arteries that contain deoxygenated blood

pulmonary and umbilical


only veins that carry oxygenated blood

pulmonary and umbilical


superior vena cava (SVC)

returns blood from the portions of the body above the heart


Inferior vena cava (IVC)

returns blood from portions of the body below the heart


hepatic portal system

one of three portal systems in which blood passes through a series of two capillary beds (as opposed to just one) before returning to the heart; blood leaving capillary beds in walls of gut passes through hepatic portal vein before reaching capillary bed of the liver


hypophyseal portal system

one of three portal systems in which blood passes through a series of two capillary beds (as opposed to just one) before returning to the heart; capillary beds in the hypothalamus then to capillary bed in anterior pituitary to allow for paracrine secretion of releasing hormones


renal portal system

one of three portal systems in which blood passes through a series of two capillary beds (as opposed to just one) before returning to the heart; blood goes to glomerulus then travels through efferent arteriole before surrounding the nephron in a capillary network called vasa recta



RBCs contain roughly 250 million molecules of hemoglobin which each can bind 4 molecules of O2 which means RBCs carry about 1 billion molecules of O2 each; no mitochondria and rely entirely on glycolysis for ATP with lactic acid as main byproduct; can live for 120 days before cells in spleen and liver phagocytize them for their parts



measure of how much of blood consists of RBCs, given as percentage norm for females is 36-46%, males is 41-53%,


measure of Hemoglobin

quantity in blood given in grams per deciliter normal for females is 12-16. Males is 13.5-17.5