Blood Pressure and Its Measurement

Blood Pressure – What is It? When the heart contracts blood is forced through the arteries blood pressure is maximum  systolic pressure typical value: 120 mmHg

Blood Pressure – What is It? When the heart contracts blood is forced through the arteries blood pressure is maximum  systolic pressure typical value: 120 mmHg When the heart muscle relaxes blood pressure is minimum  diastolic pressure typical value: 80 mmHg

Blood Pressure – What is It? When the heart contracts blood is forced through the arteries blood pressure is maximum  systolic pressure typical value: 120 mmHg When the heart muscle relaxes blood pressure is minimum  diastolic pressure typical value: 80 mmHg Typically the blood pressure is quoted as 120/80 mmHg

Blood Pressure – What is It? When the heart contracts blood is forced through the arteries blood pressure is maximum  systolic pressure typical value: 120 mmHg When the heart muscle relaxes blood pressure is minimum  diastolic pressure typical value: 80 mmHg Typically the blood pressure is quoted as 120/80 mmHg High blood pressure: either of these pressures is higher than this value Variations during a typical day: 30 to 40 mmHg (therefore measure under standard conditions)

Direct Measurement of Blood Pressure the most accurate way to measure pressure not the most convenient A barometer is attached to the vein in the horse’s neck.

Indirect Method Requires no holes in the patient Requires no long tubes listen to blood movement noise measure blood pressure cuff – pressure in the cuff equals pressure in the artery

Measuring Blood Pressure This is where a student volunteer demonstrates how to measure blood pressure.

Measure Blood Pressure Shut off blood flow  reduced blood flow noise Measure cuff pressure as it decreases  blood flow starts  noise increases Blood flow noise levels off when the artery is fully open Blood flow noise continues mm Hg

Alternative – Measure Size of Oscillations Caused by Blood Flow less accurate than previous method well suited to regular, automatic measurement blood flow starts no further increase in blood flow blood pressure decreases