Circulation Hemodynamics and pressure reg B6 Flashcards
All vessels are lined with __________
endothelium (important in controlling blood flow and pressure)
True/false: Aorta is very elastic and doesn’t need very much pressure.
True
___________ are very muscular, control BP and blood flow to tissues, SNS innervation- Alpha 1
B2 receptors- when dump epi out, you get some vasodilation
Arterioles
__________ are thin walled vessels, with only a single layer of endothelium.
Capillaries
_____ are thin walled vessels that are very compliant, low pressure, high volume, small amount of smooth muscle, SNS innervation-A1, B2 receptors
Veins
Systemic circuit flow of blood
Aorta–Artery–Arteriole–Capillaries–Venules–Veins–Vena Cava
Blood flows from ____ pressure to ___ pressure.
high
low
As resistance increases, flow ____.
slows
As pressure difference drops, flow ______
slows
__________ of blood flow is dependent upon size of total area of the vessels
Velocity
True/False: Blood flows slowest through single large vessels, and fastest through many small vessels.
False, Fastest through single large vessels
slowest through many small vessels
At which level of the vasculature is blood pressure most controlled.
Arterioles
At which level of the vasculature is venous return most controlled?
Veins
Administration of an Alpha 1 receptor agonist would decrease blood flow to which kind of vessel.
Capillaries
Why is the venous system such a low pressure system, despite containing the most volume?
High compliance vessels
As diameter goes down, ___________ goes up.
resistance
Circulatory system is arranged both ________ and in ________
in series and in parallel
Blood flows in 2 different ways, what are they?
Laminar- straight line flows
Turbulent- not straight line flows
Calculated by Reynold’s number
What can happen if you have slow blood movement?
Clots can form
A carotid bruit is most likely the result of __________
Carotid artery plaques
Which side of the heart has a greater cardiac output?
they are equal
What is the difference between systolic and diastolic pressures?
Pulse pressure
SBP-DBP= PP
120-80= 40
What is the average pressure during a complete cycle?
MAP, needs to stay above a certain volume to keep vessels open
We keep MAP stable by doing what?
altering CO (cardiac output) and TPR (Total peripheral resistance= afterload) Have to be careful because TPR also changes CO
ALtering heart rate is easy, how do you do it?
Chronotropy
How do you alter stroke volume?
Increase EDP or venous return (preload)
Increase contractility- inotropy
MAP is mainly controlled by 2 seperate system…
Baroreceptor reflex- Neural control
Renin- Angiotensin Aldosterone system- (RAAS)- Changes blood volume (Mediated by kidney)
MAP is sensed by 2 baroreceptors, what, where and what CN are they on?
Carotid sinus Barorecptor
-CN IX
Aortic arch Baroreceptor
-CN X
MAP rises?
hypertension
MAP falls?
Hemorrhage
What is a Valsave Maneuver?
When you take a crap tryin to squeeze a turd out
(squeeze abdomen, increases blood pressure) increasing afterload at heart, heart has harder time ejecting blood. (transient increase in venous return) But won’t be on test…
The _________ is very concerned about blood pressure. Needs pressure to filter blood to make urine.
Kidney
Aldosterone does what?
Increases Na reabsorption, which increases water reabsorption, which increases blood volume
Which system of blood pressure regulation would alter pressure the fastest?
Neural (Baroreceptor)
Given sufficient time, which system of blood pressure regulation would be able to create the largest change in BP?
Renal (RAAS)
Antiduretic hormone (ADh/ Vasopressin) released in response to high serum osmolarity and low blood pressure.
Vasopressin 1 receptors: arteriole constriction= Raises BP
Vasopressin 2 receptors: kidneys reabsorb more water- raises blood volume
Cardiopulmonary receptors: stretch receptors
Located in veins, atria and pulmonary arteries
Respond to high volume
Release Atrial Natriuretic Peptide- more urine production
Decrease ADH secretion- more urine
Renal vasodilation- more urine
Increased HR- indirectly more urine
What does hyperaldosteronism do?
Increase blood volume
Immediately following a heart attack, what will happen?
Reduction in Cardiac output through contractility
What happens because you have less Cardiac output? (what would it look like on a PV loop)
Increase preload to make up for cardiac output.
