Endocrine System

• Endocrine system- the glands and organs that make hormones and release them directly into the blood so they can travel to tissues and organs around the body; regulate bodily functions
• Hormones- chemical messengers that are secreted directly into the blood, which carries them to organs and tissues of the body to exert their functions
• Pituitary gland ("mastery" gland) - examples of hormones :

  • Adrenocortical trophic hormone (ACTH) - triggers the release of cortisol and androgens from the adrenal glands
  • Growth hormones - Thickens and elongates bones, grows muscle and reduces fat storage; targets liver, kidneys, cartilage, bones etc.
  • Prolactin - Stimulates milk production from the mammary gland
• Adrenal glands - produce adrenaline and noradrenaline which help regulate the metabolism, immune system, blood pressure and response to stress
• Pineal gland - Produces melatonin which helps control the circadian cycle of sleep and wakefulness
• Testes - Produces testosterone which helps in the production and storing of sperm; it also causes deeper voices, stronger muscles and body hair
• Ovaries - Produce oestrogen and progesterone which helps with breast development and causes body shape and body hair; it is also involved in the menstrual cycle, fertility and pregnancy