CV lecture 2 Flashcards
What does the measurement of BP actually measuring?
The pressure against the walls of the arteries.
Research has seen that BP has seasonal and hourly changes. What are them? :-)
lowest morning and midday, highest end of day, and lowest in summer months
What is the systolic reading?
It is the pressure exerted when the L ventricle contracts
What is the diastolic reading?
It is the amount of force sustained by the arteries during relaxation phase
What will an increase in peripheral vasculr resistance(PVR) do to diatolic reading?
It will increase the diastolic reading and cardiac workload
How do you calculate mean BP?
(SBPx1) + (DBPx2) divided by 3
What is the normal BP for a healthy adult?
Systolic <80 or 120/80
In what range do most BPs fall?
90/60 - 120/80
What If someone has a borderline BP? what would you want to know to see if its bad?
You want to look at their baseline BP. Some people, like runners, operate c lower BP than most.
What is cardiac output?
It is the amount of blood pumped by the left vntricle in 1 minute
What are 5 things that influence BP changes?
- Cardiac output
- Blood Volume
- Blood viscosity(Thickness of blood)
- Peripheral vascular resistance
- Arterial Elasticity
What is the resistance of blood flow determined by?
determined by the tone of the vascular musculature and diameter of blood vessels
Smaller the lumen of a vessel the _____ the PVR to blood flow. results in?
greater the Peripheral vascular resistance to blood flow. Which results in increased BP
As vessels dilate and resistance falls, BP will ______
lower
regulation of BP is a complex process involving primarily the:
- ANS
2. Renal system
What are some external factors that can control BP?
- Emotional factors
- Activity level
- body temperature
When activated what does α1 receptors in peripheral vascular do?
cause vasoconstriction
When activated in the heart what do α1 receptors do?
increase contractiity
When activated in the vascular smooth muscle what do α2 receptors do?
cause vasoconstriction
When activated β1 receptors in the heart will cause?
increased HR, and increased force of contraction(positive inotropic effect) and increase speed of conduction(positive dromotropic effect)
When activated, β1 receptors in the peripheral blood vessels and coronary arteries will cause?
vasodialtion
What does epinephrine and norepinephrine from the adrenal medulla do?
increase arterial pressure by icrasing both CO and systemic vascuar resistance(SVR).
What are baroreceptors?
They play a role in BP. They will sense changes in BP. When activated for high BP the sympathetic stimulation is inhibited. When activated for low BP sympathetic is activated
What happens to baroreceptors in a pt c HTN?
The baroreceptors will become adjusted to the stretching related to high BP and view it as normal. (so your body no longer makes adjustments to get your BP back to safe levels)
What do chemoreceptors do?
they are sensitive to hypoxemia and hypercapnia when they are stimulated by hypoxemia causes increase in vasoconstriction(more constriction)
How is HTN defined?
A systolic >140, diastolic BP >90
What is the significance of HTN? And what is it a significant risk factor for?
means the heart is working harder than normal, and vessels are placed under a lot of stress. High risk factor for chronic kidney disease
What are the essential or primary HTN stages?
Prehypertensive is SBP 120-139 or DBP 80-89
Stage 1 SBP 140-159 or DBP 90-99
Stage 2 SBP >160 or DBP >100
What does it mean to be secondary hypertensive?
increases in BP with a specific cause that can be identified and corrected
What are two elderly related HTN problems?
isolated systolic HTN(a loss of the elastcity inhibits expansion during systole
Also, pseudo-HTN (may occur secondary to sclerosis of large arteries) This may cause the artery to not collapse during BP reading
What are 3 hypertensive heart diseases?
- Coronary artery disease(CAD)
- Left ventricular hypertrophy
- Heart failure
Explain left ventricular hypertrophy to yourself
Initially it is an adaptive mechanism to ^ CO. But sustained HTN means the there is an increase in the cardiac workload which produces LVH. when the heart can no longer meet demands for O2, failure can develop
what are 5 complications of HTN?
- Hypertensive heart disease
- Cerebrovascular disease
- Peripheral vascular disease
- Nephrosclerosis
- Retinal damage
why does HTN cause retinal problems?
Irreversible damage begins to occur during stage 2 HTN. Arteries in te eye will start to thicken but as the pressure rises the arteries will leak fluid into the retina causing retinal hemorrhage, loss of vision
What are some lifestyle changes a person c HTN can make?
- Nutritional therapy: lower Na intake
- Lower alcohol consumption
- increase physical activity
- do not use tobacco
- stress managment
what does nicotine do?
Causes vasoconstriction
Why do people turn to medications to correct HTN?
Because the lifestyle changes have failed for one reason or another
What are the 2 main actions desired from drug therapy of HTN?
lower SVR and/or lower blood volume
What is the safest medication to administer to control HTN?
Diuretics
what are 3 types of diuretics?
Loop, thiazide, and potassium-sparing
What are the ABCD’s of drugs for HTN medications?
A: ACE inhibitor/ Angiotensin II receptor blocker (ARB)
B: Beta blockers
C: Ca++ channel blockers
D: Diuretics
How do angiotensin-converting enzyme inhibitors (ACE Inhibitor) work? And What do the names of ACE inhibitors end with?
Prevents conversion of angiotensin I into Angiotensin II which is a powerful vasoconstrictor. End in -pril (captopril, benazepril, lisinopril)
Why would a pt be prescribed a Angiotensin II receptor blocker? And what do the names of these drugs end in?
Because the ACE inhibitor has not worked, or perhap they developed a bad cough from use of ACE inhibitors. The names end in -sartan (Losartan, valsartan, irbesartan)
What do the Beta blockers do? And what do the names end in?
Beta blockers lower BP by antaganizing(lower a body function) the beta-adrenergic effect. Which means low CO, and low SNS vasoconstrictor tone, and low renin secretion. The names end in -ol (atenolol, metroprolol)
What action do Alpha blockers have? What do the names of these drugs end in?
blocks the effects of alpha 1 which dilates arterioles and veins which lowers SVR, and lowers BP. they end in -azosin (prazosin, doxazosin)
