The Endocrine System

The endocrine system is made up of several glands that secrete hormones into the bloodstream. The blood carries the hormones around the body and each hormone acts on a target organ, which produces an effect.

Compared to the nervous system, the effects of hormones are much slower but tend to be more long-lasting.

An illustrative depiction of the human endocrine system. At the top, the word "Endocrine system" is displayed. A semi-transparent human figure reveals the location of various glands in the body. The brain showcases the hypothalamus and the pituitary gland. The pineal gland is located just behind the brain. Below the throat, the thyroid and parathyroid glands are identified. The thymus is shown in the upper chest area. The pancreas is situated behind the stomach, while adrenal glands sit on top of the kidneys. For females, the ovaries are presented in the lower abdomen, and for males, the testicles are displayed. Additionally, the placenta, relevant during pregnancy, is labelled but not directly associated with the depicted figure. Each gland or organ is connected with a label by a line for easy identification.

GlandHormone produced
PituitaryMany hormones, including anti-diuretic hormone (ADH), follicle-stimulating hormone (FSH) and luteinising hormone (LH)
PancreasInsulin and glucagon
ThyroidThyroxine
AdrenalAdrenaline
OvaryOestrogen and progesterone
TestesTestosterone

Pituitary Gland

The pituitary gland, located in the brain, is often referred to as a ‘master gland’ because it can secrete many hormones into the blood. These hormones act on other glands, causing other hormones to be released. So the pituitary gland can trigger a range of effects in the body.