Physiology - Control of Arterial Blood Pressure Flashcards
What is pulse pressure?
The difference between systolic and diastolic blood pressure. Slide 6
Laminar flow is audible. True or False?
False. Laminar means the blood flows centrally and cannot be heard through a stethoscope. Slide 7
What are the Korotkoff Sounds?
The sounds you hear when listening to blood flow. Slide 9
How many Korotkoff sounds are there and what are the significant ones?
There are 5 sounds, 1 and 5 are the sounds used to determine BP. Although 5 is not really a sound but is the end of 4. Slide 9+10
What is the significance of the pressure gradient and how is it measured?
Allows blood to be driven around the systemic circulation through the aorta and the right atrium.
It is measure by MAP-Central venous pressure. Slide 12
What is the driving force for the RA?
The mean arterial pressure. Slide 12
How is MAP calculated?
(2xdiastolic)+systolic. All divided by 3. Slide 15
What is the minimum MAP needed to perfuse the coronary arteries, brain and kidneys. Slide 18
60 mmHg. Slide 18
Which vessel has the highest SVR?
Arterioles. Slide 22
What are the short term regulators for blood pressure and where are they situated?
Baroreceptors on the aorta and carotid sinus. Slide 24+25
How do baroreceptors prevent postural hypotension?
When are person stands up from lying down their MAP transiently decreases meaning there isnt so much of a stretch on vessels. Firing of baroreceptors is reduced so less dilation of vessels. The sympathetic influece causes increased SVR and venous return in veins. This corrects the slight fall in MAP. Slide 28
What is postural hypotension?
Due to the failure of baroreceptor responses to gravitational shifts in blood when moving from lying to standing. Slide 31
What happens if there is long term problems with blood pressure?
The baroreceptors can ‘re-set’ which causes them to fire if there is an acute change in MAP about the new level. Slide 33
