Perfusion Flashcards
What are the components that control blood pressure?
SVR- systemic vascular resistance and CO- cardiac output
What factors influence or affect the cardiac output?
The stroke volume and the heart rate
What are the two factors that affect the Stroke volume?
The preload- how much blood is in the left ventricle just prior to contraction and the after load which is how much blood remains after contraction
What components determine the amount of oxygen that is able to be carried in the blood
The cardiac output and the oxygen carrying ability of the blood (CaO2, carting material blood capacity)
Where are the baroreceptor located in the body and what do they do?
Located in the aortic arch, carotid bifurcation, arteries, veins and right atrium. They sense the degree of stretch in the vessels to indicate the blood pressure.
If a drop in blood pressure occurs and is sensed by the baroreceptors what is the response from the body?
Decrease in BP triggers the sympathetic nervous system to realise adrenaline and nor-adrenalin from adrenal medalla which will increase heart rate and cause vasoconstriction
What do chemoreceptor do? and where are they located?
They monitor the levels of 02, CO2 and H+ in the blood stream. Located close to the baroreceptors.
What do chemoreceptors trigger?
They primarily affect the respiratory system and cause an increase in respiratory rate and tidal volume which helps to reduce levels of CO2
They can also have an impact on the SVR by causing vasoconstriction
What affects can hormonal regulation have on the cardiovascular system?
Nor-adrenaline/Adrenalin increase heart rate and cause vasoconstriction
Angiotensin system works to increase blood volume and is realised when there is a drop in blood pressure
Anti-diuretic hormone also increases blood volume by decreasing urine output
What affect can the spleen play in blood volume?
Holds up to 300ml of blood and has 2/3 which can be expelled to increase blood volume.
Where do fluids shift between and what governs this moment?
The interstitial space, intravascular space and intracellular space, this is governed by starlings law
At what rate can fluid be shifted between compartments?
0.25ml per minute per kg- in total about 1L in an adult
