It heart is a beating muscle that pumps blood throughout the body through a network of arteries. The pressure of the flowing blood continuously loads the inner walls of the blood vessels. The blood pressure can be measured to determine the amount of blood being pumped by the heart, and to get an idea of the flexibility and condition of the vessels.
Numerous factors can affect blood pressure, including:
-the hormone levels in the body
-the water and salt content of the blood
-the condition of the heart, kidneys, nervous system and blood vessels.
Blood pressure is precisely regulated by chemicals in the body that can vary the diameter of the blood vessels according to the body’s needs. They can widen the vessels to allow more blood to pass or constrict to restrict blood flow. A hormone that helps narrow blood vessels is norepinephrine.
Norepinephrine, or noradrenaline, is made in the adrenal glands and released there into the bloodstream. It binds to proteins called alpha receptors on the surface of smooth muscle in blood vessels. As a result, the smooth muscles tighten and thus reduce the diameter of the blood vessel. Stimulation of these alpha receptors can lead to higher blood pressure.
Hypertension is a condition in which blood pressure remains abnormally high. If left untreated, hypertension can cause serious damage to the heart and blood vessels because they are overworked. Possible consequences include heart failure, stroke, heart attack, kidney damage and vasodilation. Hypertension can be fatal. There are many factors that can cause high blood pressure. These are often factors that cause narrowing of the blood vessels.
To treat hypertension, alpha-blockers may be prescribed. By selectively attaching to alpha receptors on smooth muscle cells in arterial walls, these agents prevent norepinephrine from binding. This action causes the smooth muscle cells to relax, dilating the vessels and lowering the blood pressure.
There are different brands of alpha blockers. Like all drugs, they can have side effects. It is important to consult your doctor regularly if you are taking blood pressure lowering medications.
