This diagram shows the most important blood pressure regulators.
On the Y-axis, the strength of the reflex is plotted.
On the X-axis the time or the speed of reaction of the reflex is plotted.
The baro-reflex is one of the strongest and reacts very fast; within seconds.
The chemo-reflex is also fairly strong but not as fast as the baro-reflex.
Some reflexes are not so strong and take longer to work such as fluid shift and aldosteron.
The renin-angiotensin-aldosteron system reacts quite slowly; days to months. But it is the strongest; there is no limit to its strength!!
F. The stupid Physiologist (continued):.
So, with all this new knowledge, how stupid was our physiologist?
His (it was of course a him!) mistake was to confuse short-term with long-term. In the short term he was successful; in the long term he failed.
He failed because we now know that hypertension is a problem in a long-term system.
Salt (sodium) is of course an important component that determines the blood pressure level.
In many cases, hypertension can be treated with a good diet and exercise. In that context it is important to realize that eating junk food will cause hypertension (and many other diseases!). The first thing you have to do in treating hypertension is to stop eating junk!
If a medical treatment is required, a decrease in blood volume can be obtained with diuretics (= makes more urine in the kidney). This will reduce the blood volume and therefore the blood pressure.
Another approach is to use drugs that reduce the inotropy (= contraction force) of the heart. This can be done by inhibiting the sympathetic system. The drugs are blockers of the sympathetic receptors on the heart (= beta-receptors).
A more recent approach is to inhibit the conversion of angiotensin I to angiotensin II. This conversion is done by ACE (=angiotensin converting enzyme). The drugs are therefore called ACE-inhibitors.
There are more possibilities, such as using vasodilators etc. but these need more (careful) medication.
But the main thing is to treat the hypertension because, in time, it will affect badly the heart and the vessels. The problem is that patients have no symptoms. That is why it is called the “silent killer”!