the endocrine system

• The endocrine system allows different parts of the body to communicate with each other through the secretion of hormones
• Hormones are small chemical molecules that are passed into the blood and spread throughout the body
• Some tissues have receptors specific to certain hormones, which act as signals to trigger changes inside the cells
• The main glands in the endocrine system include:

  • Pituitary gland: produces multiple hormones, some of which directly affect the body and others that stimulate other glands
  • Thyroid gland: produces thyroxine, which regulates metabolism, growth, and development
  • Adrenal glands: produce adrenaline, released during fight-or-flight response to increase heart rate and blood flow
  • Pancreas: produces insulin to regulate blood glucose concentrations
  • Testes (in males) and ovaries (in females): produce testosterone and estrogen respectively, influencing puberty and reproductive functions
• The endocrine system differs from the nervous system in that it relies on hormones transported in the blood, while the nervous system relies on electrical impulses along nerve cells
• Hormones spread more slowly and have longer-lasting effects, while nerve impulses are fast and short-lived
• Hormones act more generally throughout the body, interacting with various cells, while nerve impulses are specific to particular areas or muscles