Blood Pressure Flashcards
(105 cards)
what is blood pressure
the outwards (hydrostatic) pressure exerted by the blood on blood vessel walls
name the blood pressure; ‘the pressure exerted by the blood on the walls of the aorta and systemic arteries when the heart contracts’
systemic SYSTOLIC arterial blood pressure
name the blood pressure; the pressure exerted by the blood on the walls of the aorta and systemic arteries when the heart relaxes
Systemic DIASTOLIC Arterial Blood Pressure
what value should Systemic Diastolic Arterial Blood Pressure not reach or exceed
90 mm Hg
what value should Systemic Systolic Arterial Blood Pressure not reach or exceed
140 mm Hg
define hypertension
clinical blood pressure of 140/90 mm Hg or higher and day time average of 135/85 mm Hg or higher
what is pulse pressure
Is the difference between systolic and diastolic blood pressures
what is the normal range of values for pulse pressure
between 30 and 50 mmHg
describe the blood flow in normal arteries
laminar- central, not audible
when does an artery become completely occluded
when external pressure is applied that exceeds the systolic blood pressure- no blood flows through so no sound
what happens when the external pressure is kept between systolic and diastolic
blood flow becomes turbulent and is now audible through a stethoscope
what is the first korotkoff sound
peak systolic pressure
what are the second and third korotkoff sounds
intermittent sounds as blood pressure due to turbulent spurts of flow cyclically exceed cuff pressure
what is the fourth korotkoff sound
last sound, minimum diastolic pressure (muffled/muted)
what is the fifth korotkoff sound
no sound as return to laminar flow
at which korotkoff sound is diastolic pressure recorded
5th as more reproducible, 4th can be interpreted differently
at which korotkoff sound is systolic pressure recorded
1st
why is blood pressure essential
the pressure gradient between the aorta and the right atrium drives the blood around the systemic circulation
what is the main driving force for blood flow and why
MAP (mean arterial pressure) as RA pressure is close to 0
how is pressure gradient calculated
PG= MAP - central venous (right atrial) pressure (CVP)
what does CVP stand for
central venous pressure
what is mean arterial blood pressure (MAP)
the average arterial blood pressure during a single cardiac cycle
explain why the formula for MAP = ((2x diastolic) + systolic) / 3
As the relaxation (Diastolic) portion of the cardiac cycle is about twice as long as the contraction (Systolic) portion of the cardiac cycle
what are the units for MAP
mm Hg