What are the other endocrine glands?

• Pineal gland – Located deep inside the brain, and gradually decreases in size after puberty; it secretes melatonin, a hormone involved in the regulation of sleep patterns which is influenced by darkness and inhibited by light

• Thyroid gland – Located in the neck, consisting of two lobes that lie on either side of the trachea; controlled by the pituitary gland – secretes T3 (triiodothyronine) and T4(thyroxine) which are involved in thermoregulation (a form of homeostasis)

• Parathyroid gland – There are four parathyroid glands usually (some people have more), each about the size of a pea and embedded in the rear surface of the lobes of the thyroid; secretes parathyroid hormone, which triggers calcium release into the blood

• Thymus gland – Located in the chest, above the heart and behind the sternum; largest in infant and children, but begins to shrink after puberty; responsible for the development of the immune system – secretes thymosins, which stimulates the development of T lymphocytes

• Pancreas – Lies just below the stomach and alongside the duodenum, the first part of the small intestine; it acts as an exocrine and endocrine gland; the pancreas contains specialised cells called islets of Langerhans which control blood glucose levels by secreting glucagon and insulin which work together to maintain blood glucose levels

• Adrenal glands – Help the body respond to stress and control blood pressure, by secreting aldosterone (found in the adrenal cortex), and adrenaline and noradrenaline found in the adrenal medulla

• Adrenal medulla – Hormones produced are adrenaline and noradrenaline; adrenaline has a similar effect to that of the sympathetic division of the nervous system, as it prepares the body for the fight-or-flight response; noradrenaline has a similar effect, increasing the rate and force of the heartbeat

• Adrenal cortex – Produces more than 20 hormones, collectively known as corticosteroids; two main ones are aldosterone, which acts on the kidney to reduce the amount of sodium and increase the amount of potassium in urine, and cortisol which helps the body to withstand stress by raising blood glucose levels and assisting in the repair of damaged tissues

• Gonad gland (ovaries) – Produces progesterone and estrogen which promote the healthy development of female sex characteristics during puberty, and encourages fertility

• Gonad gland (testes) – Produces male sex hormones; secretes testosterone, the hormone involved in masculine development

Hormones secreted by other endocrine glands: