by admin on Saturday, March 13, 2010 18:20 under Interesting Facts.
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- Your circulation is the system of tubes called blood vessels which carries blood out from your heart to all your body cells and back again.
- Blood circulation was discovered in 1628 by the English physician William Harvey (1578-1657), who built on the ideas of Matteo Colombo.
- Each of the body’s 600 billion cells gets fresh blood continuously, although the blood flow is pulsating.
- On the way out from the heart, blood is pumped through vessels called arteries and arterioles.
- On the way back to the heart, blood flows through venules and veins.
- Blood flows from the arterioles to the venules through the tiniest tubes called capillaries.
- The blood circulation has two parts – the pulmonary and the systemic.
- The pulmonary circulation is the short section that carries blood which is low in oxygen from the right side of the heart to the lungs for ‘refuelling’. It then returns oxygen-rich blood to the left side of the heart.
- The systemic circulation carries oxygen-rich blood from the left side of the heart all around the body, and returns blood which is low in oxygen to the right side of the heart.
- Inside the blood, oxygen is carried by the haemoglobin in red blood cells.
by admin on Saturday, March 13, 2010 17:31 under Interesting Facts.
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- Blood is the reddish liquid that circulates around your body. It carries oxygen and food to body cells, and takes carbon dioxide and other waste away. It fights infection, keeps you warm, and distributes chemicals that control body processes.
- Blood is made up of red cells, white cells and platelets, all carried in a liquid called plasma.
- Plasma is 90% water, plus hundreds of other substances, including nutrients, hormones and special proteins for fighting infection.
- Blood plasma turns milky immediately after a meal high in fats.
- Blood platelets are tiny pieces of cell that make blood clots start to form in order to stop bleeding. Blood clots also involve a lacy, fibrous network made from a protein called fibrin. Fibrin is set in action by a sequence of chemicals called factors (factors 1 through to 8).
- The amount of blood in your body depends on your size. An adult who weighs 80 kg has about 5 litres of blood. A child who is half as heavy has half as much blood.
- A drop of blood the size of the dot on this i contains around 5 million red cells.
- If a blood donor gives 0.5 litres of blood, the body replaces the plasma in a few hours, but it takes a few weeks to replace the red cells
- Most people’s blood belongs to one of four different groups or types – A, 0, B and AB.
- Blood type 0 is the most common, followed by blood group A.
- Blood is also either Rhesus positive (Rh+) or Rhesus negative (Rh-). Around 85% of people are Rh+. The remaining 15% are Rh-.
- If your blood is Rh+ and your group is A, your blood group is said to be A positive. If your blood is Rh- and your group is 0, you are 0 negative, and so on.
- The Rhesus factors got their name because they were first identified in Rhesus monkeys.
- A transfusion is when you are given blood from another person’s body. Your blood is ‘matched’ with other blood considered safe fin- transfusion.
- Blood transfusions are given when someone has lost a lot of blood due to an injury or operation. They are also given to replace diseased blood.
