Exam II Flashcards
What are the two types of baroreceptors that help maintain BP & CO?
Carotid & Aortic
Where are the carotid baroreceptors located?
At the bifurcation of the carotid arteries
What attaches the carotid baroreceptors to the brainstem?
Glossopharyngeal
Where are the aortic baroreceptors located?
Aortic arch
What is the aortic baroreceptor a product of?
Vagus nerve
Which two catecholamines can be released locally or systemically by the adrenal gland to affect contractility & SVR?
Norepi & Epi
What are the two most protected circulatory beds?
Coronary & Central nervous system
- & to some extent kidneys
Which beds can shunt blood away from it when the body is in need?
GI
Changes in osmolarity will manage ___ levels
Vasopressin
- if Bp is really low CV system can add vasopressin
When needed the CV can stimulate the RAAS to increase BP, which mineral corticoid is associated with the RAAS?
Aldosterone
There is a reflex built into the atria where if it is over distended or too full it will stimulate the kidneys to do what? & how does it accomplish this?
Increase output by decreasing sympathetic tone to the kidneys
What is risk to having an excess in blood volume?
the more blood volume you have the slower the circulation rate –> slower circulation rate increases the risk for coagulation
What is ANP/ANF? what is its function? Where is it predominantly made?
a protein formed in the atria – predominantly RA – released when atria becomes stretched out – it gets rid of sodium & water by increase u/o in kidneys
What is BNP? Where is it formed? What is its function?
Brain natriuretic peptide – protein formed in the ventricles that works similarly to ANP
What can BNP be used as?
A marker to see how well HF treatment is going
- rise in BNP –> ventricle is being stretched out
- drop in BNP –> HF treatment is working
What is a downfall to BNP/ANF/ANP?
its affects only last about a week
If the normal amount of blood circulating in the system is 5L, how much of it is plasma & how much is Hct?
3L plasma
2L Hct
If we were to lose 20% of our circulating blood volume, how much would we lose? How much is plasma? How much is Hct?
1L
600mL plasma
400mL Hct
if we were to lose blood volume, fluid would shift from the ISF to the CV to make up for the loss, what will make it difficult to keep the volume in the CV system after it has shifted over?
The loss of capillary proteins
What is the pitfall to replacing blood volume loss with NS?
NS has no colloids –> 1/4 to 1/5 will actually stay in the CV the rest will go to the ISF
Which organ are we most concerned with when replacing blood loss with NS?
Lungs
- the water layer in the lungs is extremely thin, it has no room for extra fluid shifting over into it
What were the large sugar molecules mentioned in class that could be used as a synthetic colloid to temporarily provide an increase of oncotic pressure?
Dextran & Hetastarch
Stretch relaxation is a property of large veins, describe what this property is
it is a response by the smooth muscles in the walls of the veins –> when they become distended or tight post bolus the smooth muscle relaxes –> reducing venous pressure
What is reverse stretch relaxation?
autonomic NS overriding the smooth muscles in the veins & tightening up the walls of the veins