Please try again later. In the second half of our look at the endocrine system, Hank discusses chemical homeostasis and hormone cascades. Specifically, he looks at the hypothalamus-pituitary-thyroid axis, or HPT axis, and all the ways your body can suffer when that system, or your hormones in general, get out of whack. Table of Contents.
The top number refers to the amount of pressure in your arteries during contraction of your heart muscle; this is called âsystolicâ pressure. The bottom number refers to your blood pressure when your heart muscle is between beats; this is called âdiastolicâ pressure.For a normal reading, your blood pressure needs to show a top number thatâs lower than 120, and a bottom number thatâs lower than 80.When both your systolic and diastolic numbers are in these ranges, then you are considered by the American Heart Association (AHA) to be within the normal range for blood pressure.or a normal reading, your blood pressure needs to show a top number thatâs lower than 120, and a bottom number thatâs lower than 80. When both your systolic and diastolic numbers are in these ranges, then you are considered by the American Heart Association (AHA) to be within the normal range for blood pressure.
In the past, it was commonly thought that the diastolic pressure or bottom number was the most important blood pressure number. This mistaken idea dates back to one of the early studies of the treatment of blood pressure, where only patients with diastolic blood pressure over 90 mm were allowed into the study.