Cardio-Physio-Hemodynamics-Mitov Flashcards
Hemodynamics?
the physical behavior of blood as a fluid.
Hemodynamics examines the interrelationships between: (5 things)
flow, pressure gradients,, resistance, velocity, vessel cross-sectional area
Units of flow
mL/s
Pressure?
Force per unit area, Blood pressure measured in mmHg
Resistance definition and units?
Impedance of flow, mmHg/mL/min -pressure rise associated with an incremental rise in flow
Formula for flow?
Pressure/Resistance which is analogous to Ohm’s law
What is the consequence of too high blood flow?
A too-high flow can damage blood vessels and tissue
What is the consequence of too-low blood flow?
flow that’s too low means tissues served by the blood vessel may not receive sufficient oxygen to function.
What is the pressure that exerts on the walls of the blood vessels?
Blood pressure
Where does blood pressure originate?
With the contraction of the heart
In what 3 ways is blood pressure modified?
altering cardiac activity, vasoconstriction, or vasodilation.
What are the main 3 factors that affect resistance in blood vessels?
vessel length, vessel radius, and blood viscosity
What are the main regions of the circulatory system that generate resistance, due the small caliber of their lumen?
The arterioles and capillary networks
Which vessles in particular are able to rapidly alter resistance by altering their radius through vasodilation or vasoconstriction?
arterioles
What must be overcome in order to maintain blood flow throughout the body?
resistance
Which force overcomes resistance to maintain blood flow?
Pressure
The distribution of blood circulating to the different regions of the body is determined by the output of the and by the contractile state of the resistance vessels (arterioles) of these regions.
left ventricle
systolic arterial pressure
Peak arterial pressure reached during ejection of blood by the heart
Diastolic arterial pressure
Lowest arterial pressure reached during diastole, while the heart is relaxed and filling (not ejecting blood).
Arterial pulse pressure:
The difference between systolic and diastolic arterial pressures; dependent on stroke volume (volume ejected by one ventricle during one contraction), resistance, and arterial compliance.
Mean arterial pressure (MAP):
The average pressure over a complete cardiac cycle of systole and diastole; dependent on peripheral resistance and cardiac output (volume ejected by one ventricle per unit time).
What is the dicrotic notch (incisura)?
Only with aortic pressure
Describe how pressure changes in the cardiovascular system starting in the left atrium?
arterial pressure is a is a useful concept because it can be used to calculate overall blood flow, and thus delivery of nutrients to the various organs. It is a good indicator of perfusion pressure (ΔP).
Mean
What is a good indicator of perfusion pressure (ΔP)?
mean arterial pressure (MAP)
The difference between SBP and DBP is called?
pulse pressure
What are the two major factors that affect the pulse pressure?
(1) the stroke volume output of the heart and (2) the compliance (total distensibility) of the arterial tree.
What is the trend of blood pressure with age?
A gradual increase of SBP, MAP, and DBP
What are the name of the sounds heard when measuring BP?
Korotkoff sounds
Atherosclerosis:
disease of the large and intermediate-sized arteries in which fatty lesions called atheromatous plaques develop on the inside surfaces of the arterial walls.
arteriosclerosis:
general term that refers to thickened and stiffened blood vessels of all sizes.
Low values of systolic and pulse blood pressure have been classically considered hallmark signs of which pathology?
aortic valve stenosis
What is aortic valve stenosis?
narrowing of the aortic valve so that ventricular ejection is impeded.
What causes aortic stenosis?
often occurs as a result of calcium deposits on the leaflets of the aortic valve.
Impaired ventricular ejection, combined with the normal inflow of blood from the left atrium, results in an increased/decreased volume in the left ventricle during diastolic filling.
increased
During aortic stenosis, the increased volume in the left ventricle during diastolic filling can/cannot overcome the resistance caused by the stenotic aortic valve.
can
and allows for partial recovery of left ventricular cardiac output
Left ventricular pressure vs. right ventricular pressure during aortic stenosis?
left ventricular systolic pressures are much higher than aortic systolic pressures
What is patent ductus arteriosus?
The ductus arteriosus (a blood vessel that attaches from the aorta to the pulmonary artery during fetal development after birth) does not close as it should.
a heart valve disease in which the aortic valve does not close tightly, allowing blood to flow from the aorta (the largest blood vessel) into the left ventricle (a chamber of the heart).
Aortic regurgitation
In which pathology does the aortic incinsura dissappear?
aortic regurgitation
Abnormalities in MAP can impact blood and alter the function of the heart.
flow, normal
What is a sustained increase in diastolic blood pressure, a sustained increase in systolic blood pressure, or both.
Hypertension
How do our arteries change as we age?
loss of blood vessel elasticity and decreased compliance of large arteries
Where is the primary focus of damage due to hypertension?
on the left ventricle
What pathology can lead to cardiac hypertrophy, ischemic heart disease, coronary artery disease, kidney disease, and/or stroke?
hypertension
What are some causes of hypertension?
renal artery stenosis, drug use, sleep apnea, and adrenal diseases.
n chronic hypertension, diastolic dysfunction or ineffective left ventricular filling resulting in pulmonary congestion pressure can progress to the right/left side of the heart.
Right side
Right heart failure can then lead to decreased return to the heart, causing increased systemic venous pressures and high hepatic pressures that may impact liver function
venous
right heart failure can then lead to decreased venous return to the heart, causing increased systemic venous pressures and high hepatic pressures that may impact function
liver
What results from high pulmonary vascular pressures with certain lung diseases?
Right ventricular failure, known as cor pulmonale