Page 55 - The Miracle of Hormones

The Two Governors Of Our Body:
The Hypothalamus And The Pituitary Gland

As in this example, when the pituitary receives a signal from the re-
ceptors in the heart and veins, it means that all is well.
In the case of heavy bleeding, a person loses a lot of blood, and the
amount of blood in the veins decreases. As a result, the blood pressure
falls, a very dangerous condition.
When blood pressures falls, the signal sent to the pituitary gland
from the receptors in the heart and the veins is broken, causing the
pituitary gland to go into a state of alarm and secrete the ADH hor-
mone. The ADH hormone immediately causes the muscles around the
veins to contract, thus raising the blood pressure. In order to under-
stand this very complex, interrelated and multifaceted system, a few
details are necessary.

As long as a signal reaches the pituitary gland from the receptors in
the heart and blood vessels, everything goes well. But when blood
pressure drops, the signal ceases. This causes the pituitary gland to
take the required measures. This system resembles an infrared alarm
system. As long as the infrared signal continues, there is no prob-
lem. But if the signal is interrupted for any reason (as in the picture
above), the alarm sounds.

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