The endocrine system

• Glands secrete hormones which are small chemical molecules. They are passed into the blood stream and travel to target tissues and organs.
• Some tissues have receptors specific to hormones. The hormones can act as signals to trigger changes within the cells.
• The pituitary gland is called the master gland
• The pituitary gland is attached to the brain
• the thyroid gland produces thyroxine
• thyroxine regulates the rate of our metabolism, heart rates and growth and development
• The pituitary gland can tell other glands to release their horomes
• When the pituitary gland detects low levels of thyroxine it releases TSH which will stimulate the thyroid to produce more thyroxine
• the pituitary gland controls the thyroid using 'negative feedback'
• Our adrenal glands are located by our kidneys
• Our adrenal glands produce adrenaline which triggers a fight of flight response
• Adrenaline increases our heart rate
• The increased heart rate due to adrenaline makes blood pump faster
• The pancreas releases insulin which regulates our blood glucose concentrations
• The testes produce sperm and testosterone
• ovaries produce oestrogen and egg cells
• The endocrine system relies on hormones that are transported by blood where as the nervous system is transported along nerve cells via electrical impulses
• the endocrine system is slower but has longer lasting effects than the nervous system
• hormones act more generally than nerve impulses. nervous system is precise