What are hormones?
Hormones are chemical messengers or signals which control bodily functions and systems. In simple terms, hormones are substances made by our body which can travel in our blood to other parts of our body to control how our bodies function such as reproduction, metabolism and growth. Hormones tell each part of your body what to do, when to do it and for how long - almost like sending instructions to your organs on what they should be up to.
Where are hormones secreted from?
Hormones are released from endocrine glands, such as the thyroid, ovaries or pituitary, and enter into the bloodstream where they are then carried to specific organs and cells to perform a function unique to them. Example endocrine glands include the pituitary gland; thyroid, ovaries, testes, pancreas. So hormones travel through the body via the bloodstream until they find their target cells. Every hormone is aimed at particular cells and they bypass lots of other cells on their journey to find a target cell which matches with their specific cell structure and the hormone binds with the receptor. Once hormones find their target cell, they bind with specific protein receptors of the cell and influence the behaviour of the cell. The target cells respond in what is known as a ‘feedback loop’ by sending messages back to the gland to inform if more or less hormones are needed.
What are the different types of hormones?
There are 80 different types of hormones in humans alone. Although there are lots of different hormones in every one of us, there are three basic types of hormones based on their chemical composition. These are lipid-derived, amino acid-derived, and peptide-derived hormones.
Common hormones you might be familiar with include Cortisol, the stress hormone; Adrenaline, closely connected to exercise; and Oxytocin, the famous ‘love’ hormone which helps us bond with others. These hormones trigger how cells work and make them perform specific tasks. Some are immediate or fast-acting such as adrenaline which has a quick effect, making your heart beat faster or making your palms sweaty, and others are slower such as estrogen which can have an impact over many years such as during puberty for example.