What is Difference Between Systole and diastole?
The difference Between Systole and diastole is that Systole and diastole are two stages of the cardiac cycle. Systole is the contraction phase of the heart, where blood is pumped to the vessels, and diastole is the relaxation phase, which allows blood to enter the heart.
In a normal adult, the average systolic pressure is 120 millimeters of mercury (mmHg), while the diastolic pressure is 80 mmHg.
| Systole | Diastole | |
|---|---|---|
| Definition | It is the contraction phase of the cardiac cycle of the heart. | It is the relaxation phase of the cardiac cycle. |
| Function | The heart contracts by pumping blood from the heart to the aorta and pulmonary artery. | The heart relaxes allowing the heart chambers to be filled with blood, which comes from the pulmonary veins and vena canvas. |
| Blood pressure | High. | Low. |
| Medium pressure | The recommended systolic pressure for a normal adult is 120 mmHg. For a child, it is 100 mmHg (6 to 9 years old). | The recommended diastolic pressure for a normal adult is 80 mmHg. For children, it is 65 mmHg. |
| Blood vessels | Contracted. | Relaxed |
| Blood pressure reading | The largest number is systolic pressure. | The lowest number is the diastolic pressure. |
| Phases | It contains two phases called atrial systole and ventricular systole. | It consists of two events called atrial diastole and ventricular diastole. |
Diastolic pressure occurs at the beginning of the cardiac cycle. It is the minimum pressure in the arteries when the heart’s pumping chambers fill with blood. At the end of the cardiac cycle, systolic pressure occurs when the ventricles contract.
Blood pressure reading
The blood pressure reading is measured in millimeters of mercury (mmHg) and is supplied in two numbers.
The highest number is the systolic blood pressure reading, which represents the maximum pressure exerted when the heart contracts.
The lowest number is the diastolic blood pressure reading, which represents the minimum pressure in the arteries when the heart is at rest.
So, if the doctor says that his pressure is 120 by 80, it means that in the systole it is 120 mmHg and in the diastole, it is 80 mmHg.
As for the heartbeat, which can be heard with a stethoscope, the first stroke marks the beginning of systole, and the second is the beginning of diastole.
Normal and abnormal systolic and diastolic pressure values
In children, the systolic measurement varies from 95 to 100 mmHg and in adults, it varies from 90 to 120 mmHg. The diastolic measurement is approximately 65 mmHg in children, and in adults, it varies from 60 to 80 mmHg.
In cases of abnormality, the following numbers are identified in adults:
- Hypotension: if the systolic reading is less than 90 mmHg and / or the diastolic reading is less than 60 mmHg;
- Prehypertension: if the systolic reading is 121 to 139 mmHg and the diastolic reading is 81 to 89 mmHg;
- Stage 1 hypertension: if the systolic reading is 140 to 159 mmHg and the diastolic reading is 90 to 99 mmHg;
- Stage 2 hypertension: if the systolic reading is 160 mmHg and the diastolic reading is 100 mmHg.
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