The immune system is a collection of cells (such as B-Cells , T-Cells , etc.), chemical messengers (e.g. cytokine ) and proteins (such as immunoglobulin ) that work together to protect the body from potentially harmful, infectious micro-organisms (microscopic life-forms), such as bacteria , viruses and fungi .

The immune system plays a role in the control of cancer and other diseases, but is also the culprit in the phenomena of allergies , hypersensitivity and the rejection of transplanted organs, tissues and medical implants.

Anatomy of the Immune System

• Bone Marrow
• Lymphatic System
• Thymus