Iron is an important component of hemoglobin. The substance in red blood cells that carries oxygen from your lungs to transport it throughout your body
If you don't rest between exercise sessions you may damage you body because your muscles will have no to to rest and repair.
The second line of defence is a group of cells, tissues and organs that work together to protect the body. This is the immune system.
When a pathogen (disease-causing organism) invades the body, the neutrophils gather at the entry site and try to engulf it and destroy it.
A T helper cell will recognise only one pathogen. If the T helper cell recognises the invader, it will immediately clone to increase numbers.
After a few days of fighting off the pathogen, you will recover from your infection.
