Endocrine Glands
Biology: Edexcel IGCSE, topic 3.5.18
Endocrine Glands
The endocrine system coordinates the body’s response to changes in the environment using chemical messengers (hormones). Hormones are released by glands into the bloodstream, where they travel to target organs. There are lots of different endocrine glands:
Pituitary gland
- This is the main endocrine gland or "master gland".
- It is found in the brain and is linked to the hypothalamus (part of the brain that receives signals from receptors).
- The pituitary gland releases hormones in response to changes detected by the hypothalamus.
- Lots of these hormones trigger other glands to release more hormones.
- The pituitary gland releases ADH (anti-diuretic hormone) which acts on the kidneys to control water reabsorption from the urine.
- Two female sex hormones, FSH and LH are released by the pituitary gland.
Adrenal glands
- The two adrenal glands are situated above each kidney.
- They produce adrenaline, which triggers the ‘fight or flight’ response when an organism is presented with a dangerous situation.
Pancreas
- The pancreas produces insulin and glucagon, both of which are involved in regulating blood glucose levels.
Ovaries (female only)
- The ovaries produce oestrogen, which controls puberty and is one of the main hormones in the regulation of the menstrual cycle.
- It also releases progesterone, another female sex hormone.
Testes (male only)
- The testes produce testosterone, which controls puberty and sperm production.
Test yourself on Endocrine Glands
How is the endocrine system different from the central nervous system?
Why is the pituitary gland often called the "master gland"