Human Endocrine System (AQA GCSE Biology Combined Science): Revision Notes
📚 Revision Notes
5.2.2 Human Endocrine System
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The human body has two communication systems - the nervous system and the endocrine system . The endocrine system sends hormones (chemical messengers) around the body. When they reach a target tissue they produce a response.
It is made up of glands which secrete hormones directly into the bloodstream.
- Pituitary gland
- The master gland
- Secretes hormones into the blood to either have an effect on the body or act on other glands to stimulate them to produce different hormones
- Pancreas
- Secretes insulin
- Controls blood glucose levels
- Thyroid
- Secretes thyroxine
- Controls metabolic rate, heart rate and temperature
- Adrenal gland
- Secretes adrenaline
- Involved in the 'fight or flight' response (the body's response to stressful situations)
- Ovary
- Secretes oestrogen
- Is involved in the menstrual cycle and the development of female secondary sexual characteristics (different features that develop during puberty that distinguish a female from a male)
- Testes
- Secretes testosterone
- Is involved in the production of sperm and the development of male secondary sexual characteristics
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The blood transports the hormone to a target organ or tissue where it has an effect. Compared to the nervous system, the hormonal system is much slower but it acts for longer.