endocrine system

• works alongside nervous system to control vital functions in the body. Slower than nervous system but has very widespread and powerful effects
• various glands such as the thyroid gland produce hormones. Hormones secrete into the bloodstream and affect any cell with a receptor for that particular hormone
• most hormones affect cells in more than one organ: thyroid gland produced thyroxine which affects heart cells and cells throughout the body increasing metabolic rates
• key endocrine gland is the pituitary gland located in the brain: often called master gland because it controls the release of hormones from all the other endocrine glands