Cardiac/Vascular Function BP/HTN Control Flashcards
MAP = ____ x_____
MAP= COxTPR
Increase in CO will do what to Venous Pressure?
Decrease it.
At any one moment in the circulation:
- 50% of blood is in systemic arteries
- 50% of blood is in systemic veins
- 30% of blood is in the heart
- 5% of blood is in the systemic capillaries
- 5% of blood is in the systemic capillaries
What percentage of blood is in the venous circulation at any one moment?
65%
What percentage of blood is in the arteries at any one moment and why?
13% (arteries are less compliant because of higher pressures)
What percentage of blood is in the lungs at any one moment?
10%
What percentage of blood is in the heart at any one moment?
Lucky Number 7%
The compliance of arteries is greater than veins. True or False?
False, Fool!
Which of the following would increase the proportion of blood in systemic arteries?
- Decreased cardiac output
- A reduction in TPR
- Veno-constriction?
THREE! Veno-constriction
Unfortunately your heart stops. Your blood settles. Some sadistic scientist takes your blood pressure. What is the read out?
About 7mmHg
An increase in cardiac output will result in:
- Increase in venous pressure
- Decrease in venous pressure
- leave venous pressure the same
- Decrease in venous pressure
Does TPR change venous pressure?
Not so much bro.
Venous pressure reading of zero is relative to what?
Atmosphere.
What’s the pressure of the Inferior Vena Cava?
1 to 5mmg
What’s the pressure of the superior Vena Cava?
1 to 5mmg
Right Atrial pressure is higher than central venous pressure. True or False?
False. CVP is higher than RA.
How do you assess central venous pressure?
JVP Jugular Venous Pressure
A High JVP could mean what?
Failing heart is causing the blood to be backed up
Decrease in Venous pressure:
- Increases CO
- Decrease in CO
- Leaves CO the same
- Decrease in CO
An increase in contractility will result in:
- An Increase in CO
- Decrease in CO
- Increase in venous pressure
- decrease in venous pressure
- An Increase in CO
4. decrease in venous pressure
An increase in blood volume will result in:
- An Increase in CO
- a decrease in CO
- an increase in Venous pressure
- a decrease in venous pressure
- No clue bro.
- An Increase in CO
3. an increase in Venous pressure
A decrease in TPR will result in
- an increase in CO
- a decrease in CO
- an increase in venous pressure
- a decrease in venous pressure
- an increase in CO
3. an increase in venous pressure
What happens to central venous pressure as a result of a failing heart?
Rises.
What happens to central venous pressure as a results of poor venous return.
Falls.
List 4 causes of poor venous return to the heart:
- blood loss
- upright posture
- inadequate muscle pumps
- inadequate respiratory pumps
“Teflon” coating in the heart is what? What is it’s function?
Endothelium. Prevent sticking of cells to heart walls
What produces NO, Endothelin, Prostaglandins?
Endothelium. Duh.
How do you induce NO release to help draw blood from the 90 year old lady with tiny vessels?
Smack her veins.
Name three substances that alter smooth muscle contraction:
NO, Endothelin, Prostaglandins
NO is modulated by 4 things:
physical stimuli
hypoxia
circulating vasoactive factors
paracrine vasoactive factors (adjacent/blood cells)
Why would WBCs release vasodilators/inflmmatory mediators?
Ensure good access by immune system.
Platelets release 3 things:
Thrombin, ADP, thromboxane A2
Thrombin, ADP, thromboxane A2 are release by platelets to do what?
enhance coagulation/platelet aggregation and cause vasoconstriction.
Compliance is important in:
Diastole
What is important in systole with regards to cardiac ventricular pressures?
Active tension
Which of these LV pressures and volumes is/are within the normal range at rest?
- End systolic volume: 75ml
- stroke volume: 500ml
- End diastolic pressure: 50mmHg
- Early diastolic pressure: 5mmHg
- Early diastolic pressure: 5mmHg
What is the Frank-Starling relationship?
More stretch=more tension
More EDV=more SV
Stroke volume can be increased by:
- Increasing heart rate
- Increasing EDV
- Increasing ventricular contractility
- Increasing EDV
3. Increasing ventricular contractility
How do you increase LV pressure?
Release more calcium to increase contractility
Contractility increases as a result of:
- acidosis
- sympathetic nerve activation
- Parasympathetic nerve deactivation
- Caffeine
- Adrenaline
- Hypercapnia
- sympathetic nerve activation
- Caffeine
- Adrenaline
Which of the following is/are correct?
- During diastole the mitral valve is closed
- During isovolumetric contraction the aortic valve is closed
- During systole the tricuspid valve is open
- During isovolumetric contraction the aortic valve is closed
What determines whether or not valves are open or closed?
Only the Pressures.
Define isovolumetric.
When all valves are closed, no change in volume, only pressure.
What do you hear for mitral valve stenosis?
Early diastolic murmur
What is a murmur?
Turbulent flow of blood
First sound is:
AV valves closing
Second sounds are:
Aortic valves closing
During exercise, the size of the heart:
- Increases
- Stays the same
- Decreases
- Decreases
A decrease in LV compliance will result in:
- Increase in EDV
- Decrease in EDV
- Increase in SV
- Decrease in SV
- No clue
- Decrease in EDV
4. Decrease in SV
Afterload pressure is imposed by two things:
- Arterial hypertension
2. LV outflow tract obstruction
Define afterload:
What’s encountered by ventricle as it commences contraction
Preload is:
The stretch of myocyte fibres prior to contraction
Preload’s volume load comes from what?
Venous return
How to regulate short term BP?
Neurally
baroreflex
The body can infer the adequacy of cardiac output by measuring:
- pH
- pCO2
- pO2
- Blood Flow
- Blood Pressure
- Blood Pressure
If an Organ needs more blood:
- increase arterial resistance
- decrease arterial resistance
- reduce venous resistance
- increase capillary resistance
- decrease arterial resistance
The primary purpose of circulation is to provide:
- adequate blood flow to organs
- adequate blood pressure
- transfer of hormones
- transfer of heat
- adequate blood flow to organs
Which animal has the highest BP?
- human
- worm
- sheep
- giraffe
- cow
- Giraffe
Where are baroreceptors? 3 places?
internal carotid sinus
aortic arch
kidneys
describe the baroreceptors
thin-walled
highly innervated
quick response
stretch receptors
Where is the brainstem Cardiovascular control centre?
Medulla
How does the medulla operate the Cardiovascular control centre?
via sympathetic and parasympathetic nerves
Activation of the sympathetic nervous system does NOT?
- increase heart rate
- decrease atrioventricular conduction time
- increase cardiac contractility
- increase TPR
- increase venous tone
Does it ALL.
How do you reduce TPR?
Turn OFF sympathetic
You turn on the parasympathetic to reduce TPR?
Nope. parasympathetics don’t innervate small arterioles
What’s the whole point of the baroreflex?
Act as a buffer to smooth out variations in everyday life
What helps to dictate a reset in baroreflex and how long does it take?
ambient pressure helps dictate and it happens in 1-2 days
If baroreceptors drop the ball, what takes over when shit gets real?
Chemoreceptors
My BP is 45mmHg…. what are my baroreceptors doing?
Freaking the hell out cause they’re not firing!
Chemoreceptors are where?
bodies outside the carotid and aorta
I have low O2, going into acidosis, and high Co2, what’s most likely stimulated?
Chemoreceptors
High blood pressure predisposes to:
- kidney failure
- stroke
- liver failure
- heart failure
- coronary heart disease
- cardiac hypertrophy
- kidney failure
- stroke
- heart failure
- coronary heart disease
- cardiac hypertrophy
What’s atrial fibrillation?
The atria does the jelly dance and can’t pump diddly squat.
Mean blood pressure for men?
94
females mean blood pressure?
89
In the ageing adult:
- systolic BP rises until 60 years of age
- systolic BP rises after 60 years of age
- diastolic BP rises until 60 years of age
- diastolic BP rises after 60 years of age
- systolic BP rises until 60 years of age
- systolic BP rises after 60 years of age
- diastolic BP rises until 60 years of age
How much lower is your night BP?
~20mmHg
Why is there less variability in your BP at night?
sympathetic is turned down
while your sympathetic is turned down at night, how is your BP managed?
Auto-pilot via the renin-angiotensin system
3 reasons why your BP is lower in the summer
vasodilation
sweating
you weight less
What’s the population paradox with Hypertension?
greatest number of deaths attributable to BP occur in those with average BP.