Blood pressure genesis and regulation Flashcards
Thaxter
What is Arterial (Blood) Pressure?
Force generated by the pumping action of the heart on the wall of the aorta and arterial blood vessels per unit area
What is blood pressure measured in?
mmHg or cmH20
What is the normal blood pressure reading in adults
120/80mmHg
1mmHg = how many cm H2O
1.36cmH2O
Factors determining Arterial Blood Pressure
Cardiac Output
Peripheral resistance = systemic vascular resistance
Blood volume
What does it mean when it is said that the aorta has compliance?
Means that it has elasticity; its stretchable nature
What occurs when the aorta is said to be rigid?
When the aorta stretches it does not recoil fully (rigid); less tendency to receive blood and passes the blood along in a dampened way
The smaller the pressure change during ventricular ejection the more compliant the aorta; True or False
True
In which part of the heart is the resistance the lowest
Right atria
What are 3 important sources of resistance of blood flow
Blood viscosity
Total Blood vessel length
Blood vessel diameter
If the vessel is long what will happen to the resistance
Resistance will increase
If the diameter of the vessel is reduced how does that affect resistance
Increases resistance
Where is systemic pressure the highest
In the aorta
Systemic pressure declines throughout the pathway; True or False
True
Where is systemic pressure the lowest and what is that value
Lowest in the right atrium at 0mmHg
Why does the steepest drop in systemic pressure occurs in the arterioles
Because they manage hoe forcefully your blood moves through your body and how much goes to your tissues at any given time.
How do they do this- they can constrict
What counteracts fluctuations in blood pressure and how
Short-term neural and hormonal controls- by altering peripheral resistance eg secreting epinephrine which causes vasoconstriction etc
Long-term renal regulation- by altering blood volume
Where are chemoreceptors located
Carotid Sinus
Aortic Arch
What do chemoreceptors in the carotid monitor to?
CO2, pH or O2
What do chemoreceptors in the medulla monitor to?
CO2 and pH
What does too much acidity or CO2 indicate
Too much waste in the blood
When there is decreased O2, pH and increased CO2 what does that indicate
Decrease in parasympathetic stimulation of the heart and increase in sympathetic stimulation of the heart.
which increases heart rate and force of contraction allowing more ‘clean’ blood in systemic circulation
