Term
| How do you calculate mean arterial pressure? |
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Definition
| (2/3) diastolic + (1/3) systolic |
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Term
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Definition
| Amount (volume) of blood pumped by the heart per minute |
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Term
| What 2 control centers exist to regulate arterial pressure? |
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Definition
Central control via baroreceptor reflex
Renal control via the renin-angiotensin-aldosterone system |
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Term
| How do cardiac output and total peripheral resistance affect each other? |
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Definition
Decrease in CO will cause in increase in TPR, whereas an increase in TPR will cause a decrease in CO
These serve to keep arterial pressure steady (P=QR and in this case Q is cardiac output) |
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Term
| Explain how central control works |
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Definition
| Brainstem detects signals from baroreceptor and alters sympathetic and parasympathetic signaling pathways to alter cardiac output to adjust arterial pressure |
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Term
| What type of receptor are baroreceptors? |
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Definition
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Term
| How does renal control differ from central control? |
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Definition
Central control is neurally controlled and so it is very fast and acts through the nervous system, whereas renal control is hormone regulated and thus slower responding and more long term then central control.
Central control also alters heart rate, contractility, and vasodilation whereas renal control alters ECF volume. |
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Term
| Describe the renal regulation pathway (assuming decrease in arterial pressure) |
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Definition
1. Decreased arterial pressure leads to a decreased renal perfusion rate
2. Decreased perfusion rate leads to activation of renin, which converts angiotensinogen to angiotensin I
3. Angiotensin I gets converted to angiotensin II by ACE
4. Angiotensin II increased ECF (an increase in aldosterone aids this effect)
5. Increased ECF causes vasoconstriction, increasing TPR and increasing arterial pressure |
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Term
| What effect does vasoconstriction of arterioles have on capillary flow? |
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Definition
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Term
| What 5 factors cause vasodilation? |
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Definition
1. Low O2
2. High CO2
3. Low (acidic) pH
4. High adenosine
5. High nitric oxide
The first 3 are all in response to metabolism so they are easy to remember. High metabolism causes low O2 and high CO2, and high CO2 makes blood pH drop |
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Term
| What are Starling forces and what are the key terms in it? |
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Definition
Starling forces are gradients in pressure forces across vessels that govern the filtration rate.
The key terms are hydrolic conductance (1 in most cases), transmural pressure (forcing fluid into the interstitium) and osmotic pressure (drives fluid into the blood due to its high protein content) |
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Term
| How do oncotic pressure and blood pressure vary along the length of a capillary? |
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Definition
oncotic pressure is essentially constant
Blood pressure decreases as you travel along the length of a capillary |
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