Written by: Liz Paton, MSc

Endocrine System Overview

The endocrine system is made up of glands which are organs that secrete hormones. Hormones work by sending signals to different organs and assist with normal bodily functions such as development, reproduction and metabolism. They are important for maintaining a well-balanced and functioning system. 

Endocrine System Anatomy  

The Brain 

The brain connects the endocrine system to the nervous system via the hypothalamus. The hypothalamus is located in the lower part of the centre of the brain. Its job is to control the endocrine system by releasing hormones called neurohormones which can stimulate or inhibit the release of hormones from the pituitary gland.  

The pituitary gland is located at the base of the brain. This gland makes fundamental hormones such as somatotropin (the growth hormone) and many other hormones. This gland secretes endorphins which helps to reduce pain and reduces stress.   

The pineal gland is located in the centre of the brain, this gland produces melatonin which helps to regulate sleeping patterns. 

The Thyroid and Parathyroid Gland  

The thyroid gland is located in the neck. This gland produces hormones which help us make energy from the food we eat and increases chemical reactions in the body. The parathyroid glands are attached to the thyroid which controls the amount of calcium in the body. 

The Reproductive Glands 

The reproductive glands are the main source of producing sex hormones. This includes the ovaries in females and the testes in males. The testes produce testosterone which is important during puberty for growth and development. The ovaries produce oestrogen and progesterone which help with growth and development during puberty and are important for the menstrual cycle.   

The Adrenal Glands 

The adrenal glands are located on top of each kidney. The outer part of the gland, the adrenal cortex, make hormones that help to maintain balance of minerals and water in the body. They also help with metabolism, the immune system and development. The inner part of the gland, the adrenal medulla produces adrenaline which increases our blood pressure and heart rate in dangerous or stressful situations. 

The Pancreas 

The pancreas is part of the digestive system and produces insulin which helps to control the level of glucose in our body and help us store energy from the food we eat.