As species have evolved, their body cells have adapted to a specialised function, in order to carry out that function more efficiently. Most cells have differentiated so much that they are now incapable of carrying out other necessary functions. For example, Nerve cells have specialised to become super efficient and transmiting impulses, but are completely hopeless and extracting oxygen from the atmosphere for respiration. They rely on other specialised cells to do that job for them.
No body system can work in isolation. Every body system relies on other systems to carry out basic functions that are necessary for that systems continuation.
There are two main forms of communication in mammals:
- The Nervous system. Nerve cells are used by the body to transmit impulses around it. The activate target cells, tissues…