b'Endocrine SystemChapterThis system consists of a number of ductless glands (endocrine glands) situated in different parts of the body. They communicate to each other, along with other organs and tissues of the body by means of chemical substances, called hormones.Glands of the endocrine system include the thyroid, pituitary, pancreas, suprarenal and gonads.Hormones activate body functions through nerve impulses in the blood. Changes or variations in the amount of hormone secreted result in stimulation or depression of activity within the organs or tissues they affect, e.g. the pancreas controls important functions through the release of insulin.Reproductive System Reproduction is essential in order to continue the species from one generation to the next. This system is linked to the Endocrine System, via the male testes and the female ovaries. The male reproductive system consists of sexualglands, connecting ducts and the external genitalia. The male sexual glands are the testes, which lie in a sac (scrotum) outside the pelvic cavity.The testes produce male hormones,seminal fluid and sperm.The female reproductive systemconsists of the ovaries which produces the human egg, the uterus (womb) where the fertilised egg grows and the vagina (birth canal). 32 How Your Body Works'