The endocrine system

• Outline the function of the endocrine system

  The endocrine system provides a chemical system of communication via the blood stream - comprises of glands that secrete chemicals known as hormones.These hormones travel through the blood stream until they reach their target sites.Once reached, they bind to their specific receptors.Once bound, they regulate many bodily functions such as growth and sleep.E.g. the pituitary gland secretes the growth hormone which promotes physical growth and muscle mass while the pineal gland secretes the

  hormone melatonin which induces tiredness/sleep.
• Pituitary gland

  Located in the brain. Known as the ‘master gland’ as it secretes hormones that trigger other glands in the body to secrete hormones. It also secretes the growth hormone. This promotes physical growth and muscle mass.
• Pineal gland.

  Located in the brain. Secretes the hormone melatonin. This regulates the sleep/wake cycle by causing feelings of tiredness.
• Adrenal glands.

  Located above the kidneys. These secrete the hormone adrenaline. This produces the physiological changes seen in the fight or flight response e.g. increased breathing and heart rate.
• • Ovaries.

  Located in the female reproductive system. These secrete the hormone oestrogen. This produces female sex characteristics (e.g. breast growth) and gender characteristics (e.g. increased empathy).
• • Testes.

  Located in the male reproductive system. These secrete the hormone testosterone. This produces male sex characteristics (e.g. facial hair) and gender characteristics (e.g. increased aggression).