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120 Cards in this Set
- Front
- Back
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what are formed elements?
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cells and fragments
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what are erythrocytes?
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red blood cells
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what are leukocytes?
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white blood cells
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what are platelets?
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cell fragments
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what is hematocrit?
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percentage of blood volume that is erythrocytes
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what are the upper chambers of heart? what are lower chambers?
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upper=atrium
lower=ventricles |
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pulmonary circulation includes blood pumped from the ___ through the ___ to the ___.
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right ventricle through lungs and to left atrium
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systemic circulation includes blood pumped from the ___ through ____ then to the ___.
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left ventricle through organs and tissues and then to right atrium
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how does blood leave the left ventricle in the systemic circuit?
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through the aorta
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what is microcirculation?
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includes the arterioles, capillaries, and venules
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what is a venule?
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a small vessel that carries blood from capillary network to vein
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how does blood leave the right ventricle in the pulmonary circuit?
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the pulmonary trunk which divides into the two pulmonary arteries
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how does blood leave lungs?
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pulmonary veins
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what is a portal system?
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in liver and anterior pituitary glands blood passes through two capillary beds arranged in series and connected by veins before returning to heart
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what is hemodynamics?
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factors describing what determines the movement of blood, in particular, pressure, flow, and resistance
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what is blood pressure?
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force exerted by the blood
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what is the equation for blood flow?
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F= delta P/R
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what is viscosity?
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resistance to flow
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what is the equation for resistance? define variables
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R=8Ln/pi r^4
R= resistance L= length of tube n= viscosity r=radius of tube |
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what is the most important factor in determining resistance?
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radius of tube
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what is the fiberous sac surrounding heart called?
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pericardium
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what is the epicardium?
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inner layer of pericardium that is closely affixed to heart
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what is the wall of the heart called?
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myocardium
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what is the endothelium?
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thin layer of cells that lines heart cavities and blood vessles
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what is the right AV valve called?
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tricuspid valve
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what is the left AV valve called?
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bicuspid valve AKA mitral valve
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what is prolapse?
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when AV valves are pushed up into atria while ventricles are contracting
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what prevents prolapse?
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valves are fastened to papillary muscles of the ventricular walls by chordae tendineae
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what is the valve between right ventricle and pulmonary trunk?
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pulmonary valve
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what is the valve between left ventricle and aorta?
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aortic valve
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what are the pulmonary and aortic valves commonly called?
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semilunar valves
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how are cells of conducting system connected to heart?
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gap junctions
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what hormone is secreted by atria and what does it do?
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atrial natriureetic peptide which plays role in regulating concentration of NA+ in extracellular fluid
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what are the arteries supplying the myocardium called?
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coronary arteries
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what triggers the contraction of the cardiac muscles?
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depolarization of the plasma membrane
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what is the SA node?
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a small group of conducting system cells that create the initial depolarization
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where is the SA node located?
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in right atrium near entrance to superior vena cava
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what is the AV node? and where is it located?
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-the link between atrial depolarization and ventricular depolarization
-located in base of right atrium |
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what allows atrial contraction to be completed before ventricular excitation occurs?
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the propagation of action potentials through the AV node is relatively slow
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what does the bundle of his do?
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it carries electrical impulses from the aV node down the septum
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describe bundle branches
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pathway composed of cells that rapidly conduct electrical signals down the right and left sides of interventricular septum
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what are purkinje fibers?
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conducting cells that rapidly distribute teh impulse throughout much of the ventricles
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what is the resting membrane more permeable to: K+ or Na+?
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K+
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what does P wave correspond to?
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atrial depolarization
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what does QRS correspond to?
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ventricular depolarization
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what does T wave correspond to?
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ventricular repolarization
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why is atrial repolarization usually not present on EKG?
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because it occurs at same time as QRS complex
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what does EKG measure?
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currents generated in the extracellular fluid by changes occurring simultaneously in the cardiac cells
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what is an absolute refractory period and why is it important?
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period during and following an action potential when an excitable membrane cannot be re-excited.
important because it makes sure heart cant generate tetanic contractions |
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what is systole?
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period of ventricular contraction and blood ejection
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what is diastole?
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period of ventricular relazation and blood fillling
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what is isovolumetric ventricular contraction?
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period during first part of systole when ventricles are contracting but all valves are closed so no blood can be ejected
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what is ventricular ejection?
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phase of systole when blood exists through semilunar valves
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what is stroke volume?
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volume of blood ejected from each ventricle during systole
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what is isovolumetric ventricular relaxation?
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early phase of diastole when AV and aortic valves are closed and ventricular size remains constant
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what happens at the end of diastole?
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ventricular filling and then atrial contraction
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what is atrial fibrillation?
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state in which atria contract in a completely uncoordinated manner and fail to serve as effective pumps
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which is thinner: right ventricular wall or left?
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right
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what is soft low pitched lub associated with?
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closing of AV valves
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what is louder dub associated with?
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closure of pulmonary and aortic valves
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lub marks onset of ___ and dub marks onset of ___.
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systole
diastole |
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what can a murmur heard throughout systole suggest?
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1) stenotic pulmonary or aortic valve
2) insufficient AV valve 3) hole in interventricular septum |
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what can a murmur heard during diastole suggest?
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1) stenotic AV valve
2) insufficient pulmonary or aortic valve |
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what is cardiac output?
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volume of blood each ventricle pumps OR volume of blood flowing through either the systemic or pulmonary circuit
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what is the equation for CO?
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CO= HR * SV
CO= cardiac output HR= heart rate SV= stroke volume |
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why does SA node not cause HR of 100 bpm?
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because it is also under influence of nerves and hormones
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what three things can cause change in stroke volume?
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1) changes in preload (volume of blood in ventricles before contraction)
2) changes of sympathetic nervous system input to ventticles 3) changes in afterload (atrial pressures against which the ventricles pump) |
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what is frank-starling mechanism?
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stroke volume increases as end-diastolic volume increases
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what is the ejection fraction and what is the equation?
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rato of stroke volume to end diastolic volume
EF= SV/EDV |
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what is an echocardiography?
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ultrasonic waves are beamed at heart and returning echoes are electronically plotted by computer to produce images of heart
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echocardiography can be used to measure ___
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ejection fraction
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what is a cardio angiography?
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temporary threading of cathader through artery or vein into heart. radio active dye is injected and visualized on X ray
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the rapid depolarization of the action potential in atrial and ventricular muscle cells is due mainly to ____
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positive feedback increase in NA+ permeability
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following initial rapid depolarization, the cardiac muscle cell membrane _____ for almost the entire ____ due to ____.
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remains depolarized
contraction prolonged entry of Ca2+ into cells through plasma membrane L-type Ca2+ cells |
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what is the major signal for Ca2+ release from sarcoplasmic reticulum?
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Ca2+ entering the voltage gated L type Ca2+ channels in plasma membrane during action potential
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what is compliance? equation
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how easily a structure stretches
compliance= delta volume/delta pressure |
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the greater the compliance, the ___ stretch
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more easily
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the lesser the compliance, the ___ stretch
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harder it is to
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what is systolic pressure?
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the maximum arterial pressure reached during peak ventricular ejection
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what is diastolic pressure
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the minimum arterial pressure just before ventricular ejection begins
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what is pulse pressure?
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difference between systolic pressur and diastolic pressure
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what are the three important factors in determining pulse pressure?
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1) stroke volume
2) seed of ejection 3) arterial compliance |
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what is arteriosclerosis? what does it account for?
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stiffening of arteries that progress with age and accounts for increase in pulse pressure in older people
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what is the equation for Mean Arterial Pressure?
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MAP= DP+ 1/3 (SP-DP)
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what is the equation for blood flow through an organ?
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Forgan= (MAP-venous pressure)/ resistance organ
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what are local controls?
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mechanism independent of nerves or hormones
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what is active hyperemia?
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most organs and tissues manifest increased blood flow when metabolic activity is increased
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what is flow auto regulation?
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ability of individual arterioles to alter their resistance in response to changing blood pressure so that relatively constant blood flow is maintained
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what are myogenic responses?
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direct response of arteriolar smooth muscle to stretch
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what is reactive hyperemia?
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transient increase in blood flow following release of occlusion of blood supply
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norepinepherine is released from _____ and causes _____ whereas epinepherine causes ____
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sympathetic nervous system, vasodialation
vasoconstriction |
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what do angiotensin II and vasopresin do?
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constricts most arterioles
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what does atrial natriuretic peptide do?
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it is a potent vasodilator
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nitric oxide causes _____
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vasodilatation in basal state
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prostacyclin causes ___
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vasodilation
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what does ET-1 Cause?
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vasoconstriction
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what is shear stress?
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the force that flowing blood exerts on inner surface of arterial wall
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what is angiogenesis?
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how capillaries develop and grow
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what are intercellular clefts?
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narrow, water filled spaces that separate the flat cells of endothelial walls of capillaries
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blood velocity is dependent on _____.
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the total cross sectional area of the vessel type
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what are the three mechanisms that allow substances to move between the interstitial fluid and plasma?
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1) diffusion
2) vesicle transport 3) bulk flow |
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what is the only way that water soluble substances can gain access or exit from brain? why?
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carrier mediated transport
because brain capillaries only have tight junctions, no intercellular clefts |
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what is edema?
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accumulation of fluid in interstitial spaces
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what is lymph?
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a fluid derived from interstitial fluid
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how are lymph epithelial cells different from that of circulatory system?
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lymph cells are permeable to all interstitial fluid contents including protein
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what are the three groups of plasma proteins?
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abumins, globulins, and fibrinogen
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what is serum?
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plasma with fibrogen and other proteins involved in clotting removed as a result of clotting
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what ratio do erythrocytes have?
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high surface area to volume ratio
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what is a reticulocyte?
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young red blood cell that still has ribosomes attached
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what is the major break down product of hemoglobin?
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bilirubin
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what is hemochromatosis?
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excess iron in body
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where is the hemostatic control of iron balance?
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in intestinal epithelium
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what does ferritin do?
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serves as a buffer against iron defficency
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what does transferrin do?
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it transfers iron from old erythrocytes to bone marrow to be made into new erythrocytes
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what three things are required for erythrocytes to form?
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folic acid, B12, and intrinsic factor
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what is anemia?
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a decrease in ability of blood to carry oxygen due to 1) decrease in erythrocytes 2) diminished concentration of hemoglobin per erythrocyte 3) combo of both
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what is polycythemia?
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more erythrocytes than normal
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what are the five classes or leucocytes?
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1) eosinophils
2) basophils 3) neutorphils 4) monocyte 5) lymphocyte |
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how are platelets formed?
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megakaryocytes pinch off and enter circulation
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what is blood coagulation?
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transformation of blood into solid gel called a clot
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