What is cancer?
The immune system defends the body against infection and disease. It is made up of cells and organs that work together to protect the body.
The lymphatic system is part of the immune system. It includes the tonsils, spleen, thymus, lymph nodes and lymph vessels.
Blood and bone marrow
The blood is made up of blood cells in a liquid called plasma. Blood cells are made in the bone marrow, the soft spongy area inside most bones.
Endocrine system and hormones
The endocrine system is a group of glands and cells in the body that make hormones and release them into the blood.
Female sex organs and reproductive system
The female sex organs and reproductive system include the vagina, vulva, cervix, uterus, ovaries and fallopian tubes.
Male sex organs and reproductive system
The male sex organs and reproductive system include the penis, urethra, prostate, seminal vesicle, scrotum and testicles.