Circulatory System – Notes
The circulatory system consists of the heart and blood vessels.
Plasma contains suspended red blood cells, white blood cells and Platelets.
Red blood cells contain a pigment called haemoglobin.
In newborn babies, 17 to 22 gm/dl of haemoglobin should be present in the blood. For children, the normal range is between 11 and 13gm/dl and for adults it is between 12 and 18gm/dl.
Arteries carry blood away from the heart.
Veins carry blood to the heart.
Lymph is a colourless fluid. It contains less protein that plasma.
Fishes have two chambered hearts.
Amphibians and reptiles have three chambered hearts.