the endocrine system

• hormones are chemical molecules released directly into the blood
• hormones control elements of organs and cells that need constant adjustment
• the endocrine system is made up of: the pituitary gland, thyroid, adrenal gland, pancreas, ovaries (in females) and testes (in males)
• the pituitary gland produces many hormones that regulate body conditions and is sometimes called the 'master gland' because its hormones act on other glands, directing them to release hormones that bring about change
• the thyroid produces thyroxine, which regulates things like metabolism, heart rate and temperature
• the adrenal gland produces adrenaline, which is used to prepare the body for a 'fight or flight' response
• the pancreas produces insulin, which is used to lower blood glucose levels
• the ovaries produce oestrogen and progesterone, which are hormones that regulate the menstrual cycle
• the testes produce testosterone which is responsible for sperm production and male characteristics