Important Concepts Associated withthe Measurement of Blood Pressure

BP is one of the principal vital signs

BP Classification Systolic/Diastolic Values

Normal 119/79 or less

Prehypertension 120/80 to 139/89

Stage 1 Hypertension 140/90 to 159/99

Stage 2 Hypertension 160/100 or higher

Classification of hypertension (elevated blood pressure) in adults

Atrioventricular valvesAortic and pulmonary valves

Open OpenClosed

Closed ClosedOpen

ESV

Electrocardiogram

Left heart

P

1st 2nd

QRSP

Heart sounds

Atrial systole

Dicrotic notch

Left ventricle

Left atrium

EDV

SV

Aorta

T

Vent

ricul

arvo

lum

e (m

l)Pr

essu

re (m

m H

g)

VentricularSYSTOLE

AtrialSYSTOLE

VentricularDIASTOLE

“Lup” = closing of L AV valve or Mitral valve (1st heart sound)

“Dup” = closing of Aortic valve (2nd heart sound)

EDV = End Diastolic Volume ESV = End Systolic Volume

SV = Stroke Volume

Blood Pressure (BP) when measured with a sphygmomanometer mostly closely approximates aortic pressure.

Reviewof aortic

pressure:

Common carotidartery

Brachial artery

Radial artery

Femoral artery

Popliteal artery

Posterior tibialartery

Dorsalis pedisartery

Superficial temporalartery

Facial artery

More practically,blood pressure (BP)is a measure ofpressure in the brachial artery (avessel located a small distance from the aorta). The dots here represent pressure points located throughout the body.

Blood Pressure (BP)

Force exerted by circulating blood on the walls of the brachial artery(if measured traditionally)

Force exerted against walls of a blood vessel

when the heart contracts (systole)

Systolic Blood Pressure

Force exerted against walls of a blood vessel when the heart relaxes

(diastole)

Diastolic Blood Pressure

Average blood pressureor mean arterial pressure (MAP) is determined by obtaining both systolic

and diastolic values of the blood vessel.

(point of this exercise)

Where does your blood pressure fall?

And YOU thinkyou have stress!

Atrioventricular valvesAortic and pulmonary valves

Open OpenClosed

Closed ClosedOpen

ESV

Electrocardiogram

Left heart

P

1st 2nd

QRSP

Heart sounds

Atrial systole

Dicrotic notch

Left ventricle

Left atrium

EDV

SV

Aorta

T

Vent

ricul

arvo

lum

e (m

l)Pr

essu

re (m

m H

g)

VentricularSYSTOLE

VentricularDIASTOLE

“Lup” = closing of L AV valve or Mitral valve (1st heart sound)

“Dup” = closing of Aortic valve (2nd heart sound)

EDV = End Diastolic Volume ESV = End Systolic Volume

SV = Stroke Volume

Cardiac Output can be calculated with a quick and easy mathematical formula (using the above information).

Other conceptsto review:

Stroke Volume (SV)

Volume of blood pumped out by a ventricle

with each heart beat

Heart Rate (HR)

Number of beats per minute

Graph showing the change in volume (mL) of blood

in one “chamber” during a heart beat

What is the volume of blood at the end of diastole?

diastolediastole systole

EDV

Graph showing the change in volume (mL) of blood

during one heart beat

What is the volume of blood at the end of systole?

ESV

diastolediastole systole

Graph showing the change in volume (mL) of blood

during one heart beat

Therefore, what is the stroke volume?

SV

diastolediastole systole

Cardiac Output (CO)

Volume of blood (mL)pumped by each

ventricle in one minute (min)

Cardiac Output (CO)is

Heart Rate (HR) x Stroke Volume (SV)

Example:What would be the cardiac output of an

individual at rest (60 beats/min) and with no obvious heart condition (use the stroke volume already given)? Answer:CO (mL/min) = HR (60 beats/min) SV

(70 mL/beat) = 4,200 mL/min or 4.20

L/min

This means that over the course of one hour, one heart chamber at rest could eject over 240 liters of blood.

That’s over 63 gallons!

Sixty-three gallons for a little over six and a half days … this could fill a 10,000 gallon (small size) swimming pool.

With continuous exercise (120 beats per minute), that time could be cut in half (about 3 days)!

*1 Liter = 0.264172051 US Gallons

Measuring Blood Pressure

(BP)Interactive Physiology Exercise(In order to make this work, an access code

log-in is required.)Steps: Click on Tutorials > Interactive Physiology >

Chapter 19 > Cardiovascular System > Measuring Blood Pressure

(The plan here will be to complete all steps and the quizzes/worksheets in lab class.)

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