Cardiovascular System
Arteries

Arteries

Located throughout your body, the blood arteries are hollow tubes that circulate blood outward from the heart.
The heart pumps blood outwards through one main artery called the Dorsal Aorta.

The Dorsal Aorta then divides and branches out into diminishingly smaller arteries and then into even smaller ones called arterioles so that all peripherals of the body has its access to fresh, oxygen-rich blood, via some nearby arterioles.
The arterioles eventually deliver its supply of nutrition rich blood to capillaries where it is used up in many cellular level chemical reactions by the cells that are in close proximity.

Composition

Arteries and arterioles are very strong and flexible. They have to be strong enough to withstand the highest blood pressures that occur when the heart contracts.
They have three layers: a tough outer layer of tissue, a muscular middle, and a very smooth inner layer of epithelial cells that allow uninhibited passage of blood.

The muscular layer in the middle gives each artery its elastic property, which allows it to dilate and contract in synchronisation with the heartbeat. The arteries are thus a dynamic conduit, which assists the heart in pumping the blood through it.
When the heart contracts and squeezes out an impulse of blood, the arteries expand making the diameter bigger, thus allowing the passage of a larger amount of blood. This action assists the heart because the temporary larger diameter of the artery equates to lower blood pressure lower and the hence the heart does not have to work as hard.

How Arteries Contribute To High Blood Pressure

Arteries are thought to be the main contributing elements to high blood pressure problems.

Firstly, If the artery muscle layer does not work as well as it should and become less elastic, it will not dilate the artery in unison with the heartbeat as effectively and high blood pressure is likely.
This is thought to be chronically induced due to one's age to some degree; and explains why it is acceptable for people over 50 years old to have slightly higher blood pressure readings.
For people of all categories who do not regularly exercise this condition may be more acute and insidiously develop over a shorter period. However, with regular exercise the artery muscles become more relaxed  when one is at rest, and more responsive to impulses from the heart and indeed to the whole cardiovascular system.

Secondly, If an individual persists with an unhealthy diet high in cholesterol and saturated fat and low in basic nutrients, it could well lead to a build up of fatty deposits lining the inside of the arteries. This is called Atherosclorosis and is undesired because it effectively reduces the bore size of the arteries.
Hypertension will occur because the heart has to pump harder to deliver blood through what would effectively be a larger number of smaller arteries.
In addition, chunks of these deposits can ‘break off’ from inside the arteries at any time and become obstacles carried in the blood stream.
These chunks of plaque can haphazardly lodge themselves across arteries and cut off blood supply to vital organs. If this occurs in arteries within the heart this could lead to chest pains or heart attack and if it occurs in the arteries within the brain then this could lead to a brain attack / stroke.

Thirdly, if extreme hypertension persists for a long time, the over worked muscle layer will become more bulky, in a similar way to how leg or arm muscles get bulkier when body builders intensely exercise them.
This is manifested by the artery walls significantly thickening internally which effectively reduce the internal bore of the artery.

Measuring High Blood Pressure

The large artery in each arm (the brachial artery) is most used to measure blood pressure and heart beat. Because these arteries expand and contract in unison with the heart and can be felt just below the skin, the cuff of a blood pressure monitor in contact with them can easily detect blood impulses and yield a reading of blood pressure.

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Copyright © 2007 by Bilal Rose. All rights reserved