Flashcards in Coordinated Vascular Response Deck (43):
Is the right side of the heart more of a volume pump or more of a pressure pump?
Is the left side of the heart more of a volume pump or more of a pressure pump?
more of a pressure pump.
Are the vascular beds arranged in both series and parallel circuits?
YES. series within each organ and in parallel collectively to each system.
Where can we feel for pulses?
radial, brachial, carotid, femora, or dorsalis pedis
Can vascular beds regulate flow through them?
YES. This is why a patient can have a BP of 80/40 and still be adequately perfused.
What bridges the arterial and venous systems?
the capillary beds
What is the equation for MABP again?
MABP= CO * TPR
What happens to CO initially with increases in HR?
It goes up
What happens to CO with excessive increases in HR over time?
it will begin to decrease because we are decreasing cardiac filling time (diastole)
Does TPR vary throughout the body at different segments?
YES, to help direct blood flow where it needs to go
What would an alpha blocking drug do to TPR?
block vascular smooth muscle restriction and lower the BP
What would a beta blocking drug do to the heart?
decrease heart rate to decrease CO, thus lowering BP
What is MABP really reflecting?
Ohm's Law (V=I*R)
What happens to TPR when you are relaxed?
What happens to TPR when you smoke a cigarette?
nicotine stimulates the autonomic nervous system (nicotinic receptors) causing TPR to increase!
What does cocaine do to MABP?
stimulates sympathetics, increasing TPR and thus also MABP!
How can we treat hypertension?
decrease CO by decreasing SV, decrease HR (via beta blockers), give vasodilators to decrease TPR, or diuretics to make the patient pee more.
Can pulmonary afterload increase separately?
YES causing pulmonary hypertension (ex. sleep apnea pts bc they hold their breath)
Can we increase preload using an IV?
YES, which will increase volume of the venous compartment
What will the kidneys too if there is too much volume?
they will get rid of it as urine, thus decreasing BP.
How does the brain monitor fluid in the body?
What do we do if we have to much blood volume?
get rid of it via the kidneys
What do we do if we don't have enough blood volume?
retain it via the kidneys
What will happen if the kidney doesn't regulate electrolytes (Na+, K+...) appropriately?
You can get dysrhythmias. Then we may need to use a defibrillator to activate the voltage channels to shut things down
How do you localize poor blood flow?
Look at the precordial leads on the EKG.
What can an echocardiogram help you to do?
find vascular disease, stroke volume (via doppler) and if you know the HR you can compute the CO, EDV, valve function
How does cerebral circulation get there?
via the carotids and circle of willis
Can the brain autoregulate?
YES, meaning it can maintain a constant blood flow with varying BP. Ex. hanging upside down on the monkey bars will induce vasoconstriction to prevent too much blood flow to the head.
How does blood flow through the kidneys?
In through the afferent arteriole, through the capillaries of the glomerulus, out the efferent arteriole and down the vasa recta. These act as the filter to keep your blood clean.
What happens if we constrict the afferent arteriole of the glomerulus?
we will decrease renal blood flow, decrease filtration, decrease urinary output, and thus increase BP proximal to that!
What happens if we constrict the efferent arteriole of the glomerulus?
it will increase resistance distal to the glomerular capillary beds, increasing the hydrostatic pressure of the glomerular capillaries and thus increase filtration and urinary output!
Can the kidney autoregulate?
What is the largest organ in the body?
What will the cutaneous circulation do if its cold outside?
vasoconstrict, to prevent heat from dissipating, keeping heat inside the body
What can excessive HR lead to?
decrease time during diastole for coronary perfusion, thus inducing ischemia! (rate induced ischemia)
What is the outcome of autoregulation?
This is why blood flow remains relatively unchanged at both low and high BP.
What organs have autoregulation?
brain, heart, and kidney
Where are the important peripheral vascular beds?
glomerulus, skin, testes, and brain and these work together to redistribute blood flow as needed
How does blood flow increase so drastically to the muscles during exercise?
motor end plates getting cholinergic stimulation causing the muscle to contract and relax. ATP gets broken down to ADP, AMP, adenosine, this builds up along with K+, causing the vascular beds to dilate in order to wash out these components to the kidney where it will be removed. So this is the tissue regulation of blood flow.
What do the pre-capillary sphincters provide?
What will the metabolites, K+, and adenosine do?
cause vasoconstriction or vasodilation
What is the functionality of the capillary vascular bed a function of?
regional control (metabolites, K+, adenosine), its autoregulatory capabilities if it can do that (brain, kidney heart), and sympathetic outflow from the brain causing constriction or dilation