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Ch 5 Cir System
A & P Paramedic
Question | Answer |
---|---|
absolute refractory period | the early phase of repolarizationin which the cell contains such a large cocentration of ions that it cannot be stimulated to depolarize |
afterload | the pressure in the aorta against which the left ventricle must pump blood |
agranulocytes | leukocytes that lack granules |
alpha effect | stimulation of alpha receptors that results in vasoconstriction |
anemia | adecrease in the number of red blood cells, for any reason |
anterior descending coronary artery | one of the two brances of the left main coronary artery |
antibodies | proteins within plasma that react with antigens |
antigens | substances on the surface of erythrocytes that are recognized by the immune system |
aorta | the largest aretery in the body, which carries oxygenated blood from the left ventricle to the entire body |
aortic arch | one of the tree described portions of the aorta; gives rise to the reight brachiocephalic, left common carotid, and left subclavian arteries |
arteriosclerosis | the deposition of calcium in the arterial walls that results in a loss of elasticity and concomiant reduction in blood floww |
ascending aorta | the first of three portions of the aorta; gives rese to two brances, the right and left main coronary arteries |
atherosclerosis | a disorder characterized by the formation of plaques of material, mostly lipids and cholesterol, on the inner arterial walls |
atrioventricular (AV) node | the site located in the right atrium adjacent to the septum that is responsible for transiently slowing electrican conduction |
atrioventricular valves | the two valves through which blood flows from the atria to the ventricles |
atrium | one of the two chambers in the heart that receives blood back from the body |
automaticity | the ability of cardiac cells to generate an impulse to contract even when there is no external nervous stimulus |
axillary vein | the vein that is formed from the combination of the basilic and cephalic veins; it drains into the subclavian venin |
baroreceptors | receptors in the blood vessels, kidneys, brain, and heart that respond to changes in pressure in the heart or main arteries to help maintain homeostasis |
basilar artery | the artery that is formed when the left and right vertebral arteries unite after entering the brain through the foramen magnum |
basilic vein | one of the two major veins of the arm, it combines with the cephalic vein to form the axillary vein |
basophils | the least common of all granulocytes; they are important in both allergic and inflammatory reactions |
beta effect | stimulation of beta receptors that results in increased inotropic, dromotropic, and chronotropic states |
bilirubin | a waste product of red blood cell destruction that undergoes further metabolism in the liver |
blood | the fluid tissue that is pumped by the heart through the arteries, veins, and capillaries and consist of plasma, erythrocytes, leukocytes and platelets |
bruit | an abnormal "whooshing-like" sound indicating chaotic blood flow within a blood vessel |
bundle of His | part of the conduction system of the heart; a continuation of the atrioventricular node |
capillaries | thin-walled vessels that allow oxygen and nutrients to pass out into the cells and allow carbon dioxide and waste products to pass from the cells into the capillaries |
cardiac cycle | the pumping process begins with the onset of myocardial contraction and ends with the beginning of the next contraction |
cardiac outpud | expressed as liters per minute, amount of blood pumped through the circulatory system in 1 minute |
cardiac tamponade | alife-threatening state of shock taht develops as a result of a large pericardial effusion |
carotid bifurcation | the point of division at which the common carotid artery branches at the angle of the mandible into the internal and external carotid arteries |
carotid canals | an opening in the cranial vault through which the carotid arteries enter |
carotid sinus | a slight dilatation in the carotid bifurcation that contains structures that are important in the regulation of blood pressure |
cephalic vein | one of the two major veins of the arm that combine to form the axillary vein |
cerebellum | the part of the brain that is located dorsal to the pons and is responsible for coordination and balance |
cerebral arteries | the arteries that supply blood to large portions of the cerebral cortex of the brain |
chemoreceptors | receptors inthe blood vessels, kidneys, brain, and heart that respond to changes in chemical composition of the blood to help maintain homeostasis |
chordae tendineae cordis | small muscular strands that attach the ventricles and the valves, preventing regurgitation of blood throught the valves from the ventricles to the atria |
chronotropic state | related to the control of the heart's rate of contraction |
circle of Willis | an interconnectionof the anterior crerbral arteries and the anterior communicating artery, which forms an important source of collateral circulation to the brain |
circumflex coronary artery | one of the tow branches of the left main coronary artery |
conduction system | a group of complex electrical tissues within the heart that iniciate and transmit stimuli that result in contractions of myocardial tissue |
conductivity | the ability of cardic cells to conduct electrical impulses |
contractility | the strength of heart muscle contraction |
coronary arteries | arteries that arise from the aorta shortlyafter it leaves the left ventricle and supply the heart withoxigen and nutrients |
coronary artery disease (CAP) | the condition that results when either atherosclerosos or arteriosclerosis is present in the arterial walls |
coronary sinus | veins that collect blood that is returning from the walls of the heart |
cusps | the flaps that comprise the heart valves |
depolarization | the process of electrical discharge and flow of electrical activity from a cell |
descending aorta | one of the three portions of the aorta, is is the longest portion and extends through the thorax and abdomen into the pelvis |
diapedesis | a process whereby leukocytes leave blood vessels to move toward tissue where they are needed most |
dorsalis pedis artery | a continuation of the anterior tibial artery at the foot |
dromotropic state | related to the control of the heart's conduction rate |
ejection fraction | the portion of the blood ejected from the ventricle during systole |
electrical potential | an electrical charge difference that is created by the difference in sodium and potassium concentration across the cell membrane at any given instant |
electrocardiogram (ECG) | a graphic recording of the electrical activity of the heart |
embolus | a piece of clot that travels from one part of the body to another, potentially becoming an obstruction to blood flow |
endocarditis | infection of a heart valve |
eosinophils | granulocytes that contain granules that stain bright red with the acidic stain, eosin, and funciton in the body's allergic response |
epicardium | the layer of the serous pericardium that lies closely against the heart; aka visceral pericardium |
epinephrine | a naturally occurring hormone with a greater stimulatory effect on beta receptors that also may be given as a cardiac drug |
erythroblastosis fetalis | a serious condition that results when a pregnan woman's blood type is incompatible with the fetus' blood type and antibodies from the mother enter the fetal circulation and destroy the fetus' RBC |
erythrocytes | disk-shaped cells that carry oxygen to the tissues; aka red blood cells |
erythropoiesis | the process by which RBC are made |
excitability | a property of cardiac cells that provides the cells with the ability torespond to electrical impulses |
femoral artery | a continuation of the external ilial artery, it supplies circulation to the thigh, external genitalia, anterior abdominal wall, and knee |
femoral vein | a continuation of the saphenous vein that drains into the external iliac vein |
fibrin | a white insoluble protein formed in the clotting process |
foramen ovale | an opening between the two atria that is present in the fetus but closes shortly after birth. |
fossa ovalis | a depression between the reght and left atria that indicates where the foramen ovale had been located in the fetus |
granulocytes | a type of leukocyte that has alarge cytoplasmic granules that are easily seen with a simple light microscope |
heart | a muscular, cone-cone shaped organ whose function is to pump blood throughout the body |
hemartopoiesis | the process of blood cell production in the bone marrow; aka hemopoiesis |
hemoglobin | the protein in RBC that gives them their reddish color, it binds oxygen absorbed in the lungs and transports it to the tissues where it is needed |
hemostasis | control of bleeding by formation of a blood clot |
heparin | a substance found in large amounts in basophils that inhibits blood clotting |
hepatic portal system | a specialized part of the venous system that drains blood from the liver, stomach, intestines, and spleen |
hepatic veins | the veins to which blood empties after liver cells in the sinusoids of the liver extract nutrients, filter the blood, and metabolize various drugs |
histamine | a substance found in large amounts in basophils that increases tissue inflammation |
inferior vena cava | one of two major large veins that return deoxygenated blood to the heart via the right atrium. Blood from the lower body is return to the hert by the inferior vena cava |
inotropic state | related to the strength of the heart's contraction |
interatrial septum | a membrane that separates the right and left atria |
interventricular septum | a thick wall that separates the right and left ventricles |
ischemia | insufficient oxygen at a particular tissue site often associated with obstruction of areterial blood flow to the site |
jaundice | a yellowing of the skin adn sclera because of excessive concentrations of bilirubin in the blood |
jugular veins | the two main veins that drain the head and neck |
leukemia | a cancerous condition in which certain cell lines begin to grow abnormally fast and invade other tissues |
leukocytes | white blood cells that are responsible for fighting infection |