Vital Sign. Blood Pressure. Flashcards Preview

Introduction To Midwifery > Vital Sign. Blood Pressure. > Flashcards

Flashcards in Vital Sign. Blood Pressure. Deck (20)
Loading flashcards...
1
Q

What is hydrostatic pressure ?

A

This is the force a liquid exerts against the wall of a container such as veins and arteries

2
Q

What is blood pressure?

A

This is the force exerted by the blood on the walls of blood vessels.

3
Q

What is Systolic pressure?

A

Maximum pressure vessels during contractions of the ventricles

4
Q

What is diastolic pressure?

A

This is the pressure exerted on when the ventricles are at rest.

5
Q

Which is the top number of a blood pressure reading?

Which is the bottom number of a blood pressure reading?

A

Systolic is the top number
————————————
Diastolic is the bottom number

6
Q

What is the calculation for blood pressure?

A

BP = Cardiac output x Peripheral resistance

7
Q

What is cardiac output?

A

This is the volume of blood pumped out by the left ventricle into the aorta per minute

8
Q

What is Peripheral resistance?

A

This is the measure of blood that flows through the vessels.

Peripheral resistance is affected by vasoconstriction and vasodilation

9
Q

What 4 things control blood pressure?

A

The sympathetic nervous system
Baroreceptors
Chemoreceptors
Kidneys

10
Q

How does the sympathetic nervous system control blood pressure?

A

High BP causes the SNS too be stimulated and vasoconstriction occurs
Low BP causes the SNS to be stimulated and vasodilation occurs

11
Q

How do baroreceptors help control blood pressure?

A

These are located in the aortic arch, internal artery and large vessels in the neck and thorax
They are stimulated by stretch
Is BP rises artery walls are stretched and the baroreceptors send impulses to the vasomotor of the brain (medulla oblongata )
This then causes vasodilation and reduces the heart rate.

12
Q

How do the chemoreceptors help control blood pressure?

A

These are found in the aortic arch and in the carotid artery
They respond to low levels of oxygen
Serve hypoxia (oxygen deprivation)produces sympathetic stimulation to increase heart rate and BP

13
Q

How does the kidney help control blood pressure?

A

Low BP causes a release of renin, and enzyme which:

  • Acts on angiotensin 1 and converts it to angiotensin 2 which is a vasoconstrictor
  • this triggers the release of aldosterone from the adrenal cortex causing sodium retention and therefore fluid retention
14
Q

What are the normal ranges of blood pressure?

A

Normal range:

100/60mmHg to 140/ 90mmHg

15
Q

How does WHO define hypertension?

High blood pressure

A

When the systolic is equal too or above 140mmHg

And when the diastolic blood pressure is equal to or above 90mmHg

16
Q

What things do you need to measure blood pressure?

A

Sphygmomanometer (the cuff) and a stethoscope

Or you can use an automated device such as a dynomap.

17
Q

How do you take a blood pressure?

A
  • permission to do so
  • put cuff around bare arm
  • inflate it until you are over the systolic BP ( You should hear nothing if this done correctly)
  • slowly release the air from the cuff
  • when you hear a clear tapping noise that is the systolic reading
  • clear tapping sound will turn into a swooshing sound then a tapping sound then a muffling sound
  • when all the sound disappears completely that is the diastolic reading
18
Q

What are korotkoff sounds?

A

The tapping sounds heard through the stethoscope as the cuff is gradually deflated.

19
Q

Factors that affect a BP reading

A
  • Cuff position - level with heart. above causes lower readings. Below causes higher readings
  • Cardiac rhythm-highest in the afternoon and evening. Lowest after 12am and before 4 am.
  • Accuracy of equipment
  • External influence -e.g smoking and anxiety
  • Cuff size- cuff to small gives a higher reading
  • Observer - level of concentration and accuracy of vision and hearing
  • Technique- doing this to quick leads to inaccuracies
  • Position of woman- lying gives a lower reading. The reading is higher when sitting or standing
20
Q

What hormone causes blood pressure to fall in the second trimester?

A

Progesterone