Endocrine system

• the endocrine system produces and secretes hormones
• the endocrine uses blood vessels to deliver hormones to their target sites in the body
• hormones circulate in the bloodstream and are carried to target sites throughout the body
• hormones affect target cells
• target cells are cells with receptors for that hormone
• when enough receptor sites are stimulated it results in a physiological reaction in the cell
• timing for hormone release is critical for normal functioning
• the endocrine system

  A) hypothalamus

  B) parathyroid

  C) adrenal gland

  D) thyroid gland

  
• the hypothalamus is within the brain region which controls the pituitary gland
• the pituitary gland secretes many different hormones some of which affect other glands
• the thyroid gland affects metabolism
• the parathyroid helps regulate levels of calcium in the blood
• the adrenal gland helps trigger the fight or flight response
• the pancreas regulates the level of sugar in the blood
• the ovaries secretes female sex hormones
• the testes secretes male sex hormones
• timing of hormone release is critical for normal functioning within the body
• pituitary glands produce hormones
• pituitary glands function is to influence the release of hormones from other glands to regulate the bodys function
• the pituitary gland is controlled by the hypothalamus
• the hypothalamus receives info about the functions of the body and then uses this info to help regulate those functions
• the pituitary gland is also known as the 'master gland'
• the pituitary gland produces hormones that travel in the bloodstream to specific targets
• high levels of hormones produced in other endocrine glands can stop hypothalamus and pituitary releasing more of own hormones - negative feedback
• there are 2 parts to the pituitary gland including anterior pituitary (front) and the posterior pituitary (back)
• the anterior pituitary produces 2 hormones in control of the reproductive and sexual characteristics

  • luteinising hormone (LT)
  • follicle stimulating hormone (FSH)

  both hormones stimulate the ovaries and testes
• the adrenal gland sits at the top of the kidneys
• the adrenal gland is made up of 2 parts - adrenal cortex and the adrenal medulla
• the adrenal cortex is the outside of the adrenal gland
• the adrenal medulla is the inside of the adrenal gland
• the adrenal cortex releases hormones essential for life
• the adrenal medulla doesnt release hormones essential for life
• the adrenal cortex produces cortisol
• the adrenal cortex regulates and supports important bodily functions
• cortisol production increases in response to stress
• in the adrenal cortex if the cortisol level is low it means individual has low blood pressure, poor immune function and inability to deal with stress
• the adrenal cortex produces aldosterone which maintains blood volume and pressure
• the adrenal medulla releases adrenaline and noradrenaline
• adrenaline helps the body respond to stressful situations which increases the heart rate
• noradrenaline constricts the blood vessels causing blood pressure to increase