Final answer:
Resting or diastolic tension is the minimum pressure in the arteries during the heart's relaxation phase, diastole. It is the lower value in a blood pressure reading and should be less than 80 mm Hg. This relaxation phase, represented by the T wave on an ECG, is divided into two parts, totaling approximately 430 ms.
Step-by-step explanation:
Resting or diastolic tension refers to the pressure in the arteries when the heart is in a state of relaxation, also known as diastole. Diastolic pressure is the lower number recorded when measuring arterial blood pressure. It represents the minimal pressure in the arteries, which corresponds to the pressure that remains during the period of ventricular relaxation. A desirable diastolic pressure is generally considered to be less than 80 mm Hg.
During ventricular diastole, the heart's ventricular muscle relaxes and the pressure within the ventricles begins to fall. This occurs after the repolarization of the ventricles and corresponds to the T wave on an Electrocardiogram (ECG). The period of ventricular relaxation is divided into two phases and lasts roughly 430 ms.
When blood pressure is measured, it is expressed as a ratio of systolic to diastolic pressure (e.g., 120/80 mm Hg), with systolic pressure being the higher value during ventricular contraction and diastolic pressure being the lower value during ventricular relaxation. The diastolic pressure reflects the minimum pressure within the circulatory system and varies in the range of 60 to 110 mm Hg.