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Flashcards in Physiology Deck (11):
1

Short term regulation of BP

Baroreceptor reflex

2

Korotkoff sounds

1st is peak systolic pressure
Last sound is heard at minimum diastolic pressure. DIASTOLIC PRESSURE IS RECORDED AS THE FIFTH KOROTKOFF SOUND

3

Right atrium pressure

0
Main driving force for blood is the MAP

4

Normal MAP?

70-105mmHg

5

Minimal MAP needed to perfuse brain, arteries and kidneys?

60mmHg

6

Cardiac output

Volume of blood umped by each ventricle of the heart per minute

7

The major resistance vessels?

Arterioles

8

Where are the baroreceptors?

Aortic arch and carotid sinus
(carotid signals via IXth CN)
(aortic signals via CNX)

9

Important in moment to moment regulation of arterial blood pressure including prevention of postural changes

Baroreceptors reflex

10

What causes postural hypotension?

Results from failure of baroreceptor responses to gravitational shifts in blood, when moving from horizontal to vertical position

11

Why do baroreceptors only respond to acute changes in blood pressure?

Baroreceptors firing decreases if high blood pressure is sustained

Baroreceptors “re-set” - they will fire again only if there is an acute change in MAP above the new higher steady state level

Therefore, the Baroreceptors cannot supply information about prevailing steady state blood pressure

Control of MAP in the longer-term is largely by control of Blood Volume