Step 1: Understanding the Concept:
Blood pressure is recorded as two numbers. The higher number (systolic) represents the pressure when the heart contracts, and the lower number (diastolic) represents the pressure when the heart relaxes.
Step 2: Detailed Explanation:
1. Systolic Pressure: For a healthy young adult at rest, the systolic blood pressure is typically around 120 mmHg.
2. Diastolic Pressure: The normal resting diastolic pressure is around 80 mmHg.
3. Standard notation: This is commonly written as 120/80 mmHg.
4. Hypertension: A systolic pressure consistently above 140 mmHg is generally classified as high blood pressure.
Step 3: Final Answer:
120 mmHg is the standard reference value for normal adult systolic pressure.