Ever wondered how complicated humans are ? More complicated than them is the working of the human body. Human body needs oxygenated blood for it’s everyday functioning, this good deed is done by the blood vessels present in our body.
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Which blood vessel has the least oxygen concentration ?
There are two blood vessels which carry the least amount of oxygen concentration viz. coronary sinus and the pulmonary artery.
In case of patent foramen ovale, when pulmonary artery is carrying blood there are chances that the deoxygenated blood and oxygenated blood might mix. You must be thinking what is patent foramen ovale, if you want to know about this keep reading.
Most of the times coronary sinus is the one which carries deoxygenated blood and coronary sinus is where all the veins from myocardium empty in. So, you can think of it as a dumping ground but for blood.
Patent Foramen Ovale (PFO):
When we’re a fetus there is a hole present between the left atria and the right atria which are called the upper chambers of the heart. This hole is present before birth but it usually closes after the baby is born.
When this hole fails to close after birth it is said to be a case of Patent Foramen Ovale. So, there are chances of mixing of deoxygenated blood and oxygenated blood after birth.
What are blood vessels ?
Blood vessels are tubular like structure spread out all over are body for circulation of oxygenated blood. They carry this blood to the tissues and organs of our body. They basically are suppliers of the blood in our body. Study of blood vessels is called angiology.
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| Blood vessels in a human body |
What are the types of blood vessels ?
Blood vessels are of 3 types, which are as follows:-
Arteries:
The arteries are important because they carry the oxygenated blood away from the heart. Only pulmonary arteries are the one which carries deoxygenated blood. They show low blood pressure.
Arteries divide and redivide to form arterioles which further leads to capillaries.
The three layers of artery are – outer tunica externa, middle tunica media, and inner tunica interna.
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| Artery |
Capillaries:
As you know, capillaries are formed by division and redivison of arteriole. They are the thinnest of all the blood vessels.
The walls of the capillaries are permeable to water and dissolved substances so substances like respiratory gases, nutrients and excretory products take place through the walls of capillaries.
The walls of the capillaries are made up of squamous epithelium or endothelium. Capillaries unit to form venules (a very small vein), which collects blood from capillaries.
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| Capillary |
Veins:
Veins carry deoxygenated blood from different parts of the body to the heart for oxygenation, the only vein which does not carry deoxygenated blood is pulmonary veins.
The valves of the veins are semilunar (half-moon like structure), this prevents the blood from flowing in backward direction. These valves have three cusps or flaps. Amongst all the blood vessels veins have low blood pressure.
Veins and arteries share the same three layers of walls, just that the walls of the veins are thinner than compared to arteries.
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| Veins |
