Lecture 3 Flashcards
the amount of blood ejected from the heart in 1 minute is known as the ___ ___
cardiac output
amount of blood received by ventricle must be ___ to the amount of blood pumped out of the ventricle
equal to
amount of blood pumped out by the left ventricle must be ___ to the amount of blood pumped out by the right ventricle
equal to
how to calculate cardiac output?
stroke volume X heart rate
if the volume of blood pumped by the left side of the heart was less than that pumped by right side of the heart, what would be the result?
pulmonary edema
if the volume of blood pumped by the right side of the heart was less than that pumped by left side of the heart, what would be the result?
systemic edema
what’s the difference b/n the max and resting cardiac output?
cardiac reserve
what is stroke volume?
volume of blood ejected by a ventricle in one contraction of the heart
what is the volume of blood ejected by each ventricle in one minute?
cardiac output
what is tachycardia?
resting adult HR > 100 bpm
the amount of blood ejected by a ventricle is ___ the amount of blood received during ventricular filling
the same as
what is bradycardia?
resting adult HR < 60 bpm
what is the steady background firing of the vagus nerve to the heart?
vagal tone
what is too much calcium in blood?
how does that affect HR?
hypercalcemia –> lowers HR
what is calcium deficiency in blood?
how does that affect HR?
hypocalcemia –> raises HR
what chemicals cause increase in HR?
nicotine
thyroid hormone
caffeine
what is vagal tone?
steady background firing of the vagus nerve to the heart
the amount of tension in the ventricular myocardium immediately before it begins to contract is known as the ___
preload
A decrease in venous return to the heart leads to a(n) ______ in preload, and therefore, a(n) ______ in stroke volume.
decrease, decrease
what does the Frank-Starling law of the heart state?
stroke volume is proportional to end-diastolic volume
what is the strength of contraction for a given preload called?
contractility
glucagon and thyroid hormone ___ HR
increase
the amount of tension in the ventricular myocardium immediately before it begins to contract is called what?
preload
what do positive inotropic agents do?
increase contractility
what do positive inotropic agents do?
increased contractility
an increase in venous return to the heart leads to an ___ in preload and therefore an ___ in stroke volume
increase, increase
what is the most common cause of coronary artery disease?
artherosclerosis
which law states that stroke volume is determined by the end-diastolic volume?
Frank-Sterling
what is afterload?
the sum of all forces a ventricle must overcome before it can reject blood
how does hypertension affect afterload?
increases it
the strength of a contraction for a given preload is defined as the ___ of the myocardium
contractility
the flow of blood per given volume or mass of tissue is known as ___
perfusion
nicotine increases heart rate by increasing the secretion of what?
catecholamine
what is blood pressure?
force that blood exerts against a vessel wall
what is the effect of negative ionotropic agents?
decrease contractility
what is the narrowing of coronary arteries, usually by atherosclerosis?
coronary artery disease
what is systolic pressure minus diastolic pressure?
pulse pressure
Which force impedes the opening of the semilunar valves and opposes ventricular ejection?
afterload
Systolic pressure is the highest in which vessel?
aorta
increasing stiffness of arteries =
arteriosclerosis
what is normal BP?
what is BP for hypertension?
what is BP for hypotension
120/80
> 140/90
varies
BP is determined by what 3 variables?
resistance to flow
blood volume
cardiac output
the difference b/n systolic and diastolic pressure is ___ pressure
pulse
what affects peripheral resistance?
blood viscosity
vessel length
vessel radius
Degenerative changes of the blood vessels characterized by the presence of atheromas and often leading to calcification of the vessel wall is known as ___
atherosclerosis
what is atherosclerosis?
degenerative changes of the blood vessels characterized by the pressure of atheroma and often leading to calcification the vessel wall
what is true in a reclining individual?
mean arterial pressure is higher in the arm compared to the foot
how does radius of blood vessel affect blood flow?
F (is proportional to) r^4
3-fold increase in radius ==> 81-fold increase in flow
which arteries exert the greatest control over peripheral resistance and blood flow?
arterioles
