A01

• What is the endocrine system?

  A group of glands that secrete hormones into the bloodstream in order to regulate bodily functions
• What are the main 8 glands that make up the endocrine system?

  Hypothalamus, pituitary, thyroid, parathyroid, adrenals, pancreas, ovaries, testes
• What is the fight or flight response?

  - An evolutionary response of the body to stress

  - The body becomes physiologically aroused in readiness to fight an aggressor or flee
• What are the 2 main hormones released during the fight or flight response?

  Adrenaline and noradrenaline
• Which part of the adrenal gland releases adrenaline?

  The adrenal medulla
• What is the sympathetic state?

  When the body is physiologically aroused
• What is the parasympathetic state?

  When the body is in its resting state
• What effects do adrenaline and noradrenaline have on the body?

  Increased heart rate, blood pressure, breathing and respiration, releases glucose into bloodstream and digestion is reduced
• What happens when the stressor has passed and there is not longer a threat during the fight or flight response?

  The parasympathetic system reverses the changes made by the sympathetic system
• What is the difference between an acute and chronic stressor?

  - Acute = short-term and immediate

  - Chronic = Long-term
• What is the role of the hypothalamus?

  Stimulates and controls the release of hormones from the pituitary gland
• What are the 2 hormones released by the pituitary gland?

  1. Anterior = ACTH -> stimulates adrenal cortex and the release of cortisol during the stress response
  2. Posterior = oxytocin -> responsible for uterus contractions during childbirth
• What is the hormone released by the thyroid gland and its effect?

  Thyroxine - responsible for regulating metabolism
• What are the 2 hormones released by the adrenal gland and their effect?

  1. Adrenal medulla = adrenaline and noradrenaline -> key hormones in fight or flight response
  2. Adrenal cortex = cortisol -> stimulates the release of glucose to provide the body with energy, whilst suppressing the immune system
• What is the hormone released by the pancreas and its effect?

  Insulin -> controls blood sugar levels
• What is the hormone released by the ovaries and its effect?

  Oestrogen:

  • Responsible for the development of female sex characteristics during puberty and controls the regulation of the female reproductive system, including the menstrual cycle and pregnancy
• What is the hormone released by testes and its effect?

  Testosterone - responsible for the development of male sex characteristics during puberty
• Describe how the nervous and endocrine system work together during the fight or flight response

  1. Amygdala send alarm signal to hypothalamus
  2. This activates 2 separate responses (sympatho adrenal medullary = acute stressors and hypothalamic pituitary adrenal for chronic stressors)
  3. Acute stressors -> SAM triggers the sympathetic branch of ANS which stimulates the adrenal medulla to release adrenaline and noradrenaline
  4. This prepares body for physical exertion
  5. When stressor has passed parasympathetic system reverses these changes
• What are hormones?

  A chemical messenger that circulates in the bloodstream and controls how cells/ organs work/ influences behaviour or mood