Blood
Do you think Blood is a tissue or a fluid? What is it made up from? and what does it do? lets explore...
Although blood is technically a tissue, we generally classify it as a bodily fluid. It performs a number of functions, including taking oxygen and nutrients to the tissues, and carrying away waste products such as carbon dioxide.
What is its Structure.
Blood has various components, including:
- Red blood cells
- White blood cells
- Platelets
- Plasma the fluid in which all these others are suspended.
Plasma comprises around 55% of blood fluid, and in addition to the main comments mentioned above, also carries substances such as dissolved proteins, glucose, mineral ions, hormones, and carbon dioxide.
What does it do.
The blood cells have specialised functions. Red blood cells (RBCs, or erythrocytes) and the most plentiful, and contain hemoglobin, an iron-containing protein, which facilitates transportation of oxygen by increasing its solubility in blood.
White blood cells, on the other hand, are your bodys sentries. Whenever a foreign body appears, they swarm around it. Sometimes they attack it by producing protective antibodies to overpower the invader, at other times they simply surround and devour the bacteria.
Less well known is the role of platelets. These irregularly-shaped, colorless bodies prevent you from bleeding excessively when you are injured. When bleeding from a wound suddenly occurs, they crowd wound site and attempt to block the blood flow. Their sticky surface lets them form clots to stop bleeding.
