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1 - Fish
Blood Constituents
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| Cells |
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Blood
cells of fishes are categorised into two main groups.
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Definitions |
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| ERYTHROCYTE:
The term erythrocytes refers collectively to those nucleated blood cells
which carry the red-pigmented protein haemoglobin.
Erythrocytes differ from leucocytes, and their primary function is
in the transport of gases throughout the body.
HAEMOGLOBIN: Red-pigmented protein occurring in the blood cells of vertebrates and elsewhere in the animal kingdom. Haemoglobin combines readily with oxygen to form oxyhaemoglobin responsible for transferring oxygen through the blood system. Haemoglobin is made up of the colourless protein globin, and the red-yellow pigment haeme which contains iron. Oxygen is transported in combination with the ferrous iron of the haeme. LEUCOCYTE: The term leucocytes refers collectively to those non-pigmented, nucleated blood cells whose primary function is to combat infection and in some cases to phagocytose and digest debris. They differ from erythrocytes, in that they leave the vascular system to carry out their tasks by passing through the walls of small blood vessels. PHAGOCYTOSIS: The intracellular uptake of solid particles by cells, either for nutritional purposes (e.g. food), or in the case of phagocytes such as macrophages and granulocytes as a defence mechanism (foreign bodies). |
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