Hormones

Hormones are chemical substances that help to regulate processes in the body. Hormones are secreted by glands and travel to their target organs in the bloodstream. Several hormones are involved in the female menstrual cycle.

Hormones are chemicals secreted by glands in the body. Different hormones affect different target organs. The bloodstream transports hormones from the glands to the target organs.

Gland Hormone Target organs Effect adrenal gland adrenalin vital organs, eg liver and heart Prepares body for action - 'fight or flight'. ovary oestrogen ovaries, uterus, pituitary gland Controls puberty and the menstrual cycle in females; stimulates production of LH and suppresses the production of FSH in the pituitary gland. ovary progesterone uterus Maintains the lining of the womb - suppresses FSH production in the pituitary gland. pancreas insulin liver Controls blood sugar levels. pituitary gland anti-diuretic hormone (ADH) kidney Controls blood water level by triggering uptake of water in kidneys. pituitary gland follicle stimulating hormone (FSH) ovaries Triggers egg ripening and oestrogen production in ovaries. pituitary gland luteinising hormone (LH) ovaries Triggers egg release and progesterone production in ovaries. testes testosterone male reproductive organs Controls puberty in males.