*Physiology 4 (lecture 4) Flashcards
What is blood pressure?
The outward (hydrostatic) pressure exerted by blood on blood vessel walls
What is the systemic systolic arterial blood pressure?
the pressure exerted by the blood on the walls of the aorta and systemic arteries when the heart contracts
What should the systemic systolic blood pressure not exceed under resting conditions?
140mmHg
What is the systemic diastolic blood pressure?
The pressure exerted by the blood on the walls of the aorta and systemic arteries when the heart relaxes
What should the systemic diastolic blood pressure not exceed?
90mmHg
What is the word used to describe the way in which blood should normally flow through blood vessels, meaning it is not heard through a blood vessel?
Laminar
When is blood flow heard through a stethoscope in terms of taking blood pressure?
Not heard when no pressure is applied (laminar flow) or when pressure greater than the systolic blood pressure is applied (flow is blocked)
If the external pressure is between systolic and diastolic pressure, the flow will be turbulent (artery collapses and reopens with each heart beat = snapping sound)
These kortkoff sounds can be heard through a stethoscope
What is the RA pressure?
Close to 0
What drives the blood around the systemic circulation?
A pressure gradient between the aorta and right atrium
What is the central venous pressure?
pressure in the right atrium
What does the pressure gradient that drives the blood around the systemic circulation =?
Pressure gradient = MAP - CVP
What is the mean arterial pressure?
The average arterial blood pressure during a single cardiac cycle, which involves contraction and relaxation of the heart
MAP =?
[(2 X diastolic pressure) + systolic pressure] / 3 or DBP + 1/3rd difference between SBP and DBP
MAP = CO X TPR
MAP = (HR X SV) X TPR
How can MAP be estimated?
By adding DBP + 1/3rd of pulse pressure
What is pulse pressure?
The difference between systolic and diastolic blood pressure readings