A hormone is a chemical messenger that carries a signal from one cell to another. Hormones are released from cells, glands or organs in one part of the body and affect cells in another part of the body. Hormones in animals are usually carried in the blood, but plants have hormones too, called phytohormones.
Hormones are really important and can have lots of different effects. In mammals they can affect growth, activate the immune system, regulate metabolism and control the reproductive cycle, and in plants they help to control growth, flowering and the ripening of fruit along with many other things.
Here are some examples of hormones in mammals that you might have heard of:
Testosterone and oestrogen regulate puberty and fertility in males and females.
Insulin and glucagon are involved in regulating sugar levels in the body
Growth hormone stimulates growth and cell division
Antiduretic hormone helps to regulate water retention in the kidneys
It’s really important that hormones are in balance in the body. For example too much growth hormone can cause gigantism or acromegaly, while having too little growth hormones can cause dwarfism. The word acromegaly comes from the Greek words for extremities and enlargement and relates to the symptoms of abnormal growth of hands and feet in people with this illness.
In this zone there is a scientist who researches the different hormones that affect fertility, and a scientist who wants to make better drugs to treat people with type 2 diabetes. There is also a scientist who investigates the signals that cause us to lose muscle cells as we get older, another who specialises in researching how hormones affect the male body and another who works in a hospital looking at the link between sugar and hormones.