The Endocrine System

• The endocrine system involves gland and hormones.
• A hormone is a protein chemical which binds to the receptors of its target tissue to cause a biological response.
• Hormones are transported via the bloodstream.
• Hormone responses have a greater longevity [lasting period] because they remain bound to their target tissue for lots of time. Also they are transported via the blood stream which is slower and takes longer to break down.
• The pituitary gland is a master gland, releasing ADH, growth hormone, FSH, TSH and LH.
• ADH - anti-diuretic hormone which controls the amount of urine produced in the kidney [target tissue]
• Growth hormone controls the rate of growth in children [via cell division].
• LH [luteinizing hormone] stimulates ovulation [release of an egg].
• TSH stimulates the thyroid gland to make thyroxine.
• FSH stimulates the ovarian follicle to mature and release an egg and release oestrogen.
• The adrenal gland releases adrenaline.
• The thyroid controls the basal metabolic rate of the body via thyroxine.
• The pancreas uses insulin and glucagon to control blood glucose levels.
• The ovaries control the development of female secondary sexual characteristics and is involved in the menstrual cycle. Releases oestrogen to prepare the uterus for possible pregnancy.
• The testes control the development of male secondary sexual characteristics and is involved in the production of sperm via testosterone.
• Adrenaline is secreted from the adrenal gland when a person is scared or excited.
• Adrenaline

  • increase heart rate
  • increase breathing rate
  • decreased pain perception
  • pupil dilation
• Adrenaline's target tissue is the heart's pacemaker.