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)
