Saturday, July 4, 2009

Blood

Cellular component of blood consist of red blood cell (erythrocytes), platelets & white blood cell (leucocytes).

Erythroctes

#It have large surface area to volume ratio for gaseous exchange.
#Although small in size, but each of them contain 250 million of haemoglobin(oxygen-carrying pigment that give red colour to blood)

Leucocytes

*colourless & have nucleus
*not contain haemoglobin
*divided into to : 1)granular
2)agranular (see image)


*the function of leucocytes is to fight infection in the human body especially in the insterstitial fluid.
* they also produce immune response against foreign substances that enter our body.

Wonders of Human Body

1) Function of body circulatory system is for transporting the nutrients & oxygen needed in cell at the same time carries waste materials away from it.

2) 3 major components of the circulatory system is-
a)Blood- connective tissue made of liquid plasma,blood cell & platelets.
(medium of transport in human & animal)
b)heart- muscular pump, regulate blood all over the body
c)blood vessel- vessels (artery,vein,capillary)

But in arthropods(insects), the medium of transport is called haemolymph.

Function of blood


1)Blood transport oxygen from lung to the cells & carbon dioxide from cell to the lung to be exhaled.
2)Blood also transport hormones,nutrients & waste product.
3)Blood helps in regulating pH of the body fluid, control body temperature and water content in cell.
4)Blood clot also protect our body from excessive lost of blood.

Function of haemolymph

It transport nutrient, water, inorganic salt & orgnic substance throughout the haemocoel, but it do not transport respiratory gases because gases are transported via tracheal system.

Image of human circulatory system