Adipose tissue (body fat) is crucial for health. Along with fat cells, adipose tissue contains numerous nerve cells and blood vessels, storing and releasing energy to fuel the body and releasing important hormones vital to the body's needs.

The adrenal glands are small glands attached to the top of each kidney. The human body has two adrenal glands that release chemical messengers called hormones into the bloodstream. These hormones travel via the blood to have an action in other parts of the human body.

The hypothalamus is a part of the brain that has a vital role in controlling many bodily functions including the release of hormones from the pituitary gland.

The kidneys are specialised organs that ensure unwanted substances and excess water are removed from the bloodstream.

The ovaries produce and release eggs (oocytes) into the female reproductive tract at the mid-point of each menstrual cycle. They also produce the female hormones oestrogen and progesterone and androgens.

The pancreas is an organ that serves two vital purposes: to aid food digestion and to produce hormones that mainly serve to control levels of energy in the blood.

The parathyroid glands are situated in the neck and control the levels of calcium in the blood.

The pineal gland is situated in the middle of the human brain and is the major site of the body's melatonin production.

The pituitary gland is a small pea-sized gland that plays a major role in regulating vital body functions and general wellbeing. It is referred to as the body's 'master gland' because it controls the activity of most other hormone-secreting glands.

The placenta is a temporary endocrine organ formed during pregnancy, which produces hormones important in the maintenance of a healthy pregnancy and in preparation for labour and breastfeeding.

The testes are two oval-shaped male reproductive glands that produce sperm and the hormone testosterone.

The thyroid gland is part of the endocrine system and produces thyroid hormones, which are important for metabolic health.