Endocrine system

• What is the endocrine system?

  The endocrine system is a network of glands throughout the body that manufacture and secrete chemical messengers called hormones. It uses blood vessels to deliver hormones to target sites in the body.
• What is the function of the endocrine system?

  • Helps regulate the activity of cells and organs in the body
  • Communicates chemical messages to the organs of the body
• Thyroid

  • Produces thyroxine
  • Increases heart rate and metabolic rates
• Pineal gland

  • Produces melatonin
  • Regulates sleep/wake cycle
• Pituitary gland

  • Major endocrine gland in the brain
  • Controls release of hormones all over body
  • Divided into anterior and posterior
• Anterior pituitary gland

  • Secretes LH and FSH (luteinising hormone and follicle stimulating hormone)
  • Stimulates ovaries to produce oestrogen and progesterone
• Posterior pituitary gland

  • Releases oxytocin
  • Helps uterus to contract in labour
  • Involved in bonding/attachment processes
• Pancreas

  • Produces insulin and glucagon
  • Regulates blood sugar levels
• How is the endocrine system involved in fight or flight?

  • Releasing hormones like adrenaline into the bloodstream.
  • When a threat is detected, the hypothalamus activates the adrenal medulla (part of the adrenal glands).
  • The adrenal medulla secretes adrenaline, which increases heart rate, breathing rate, and glucose release for energy.
  • This prepares the body to either fight the threat or run away from it (flight).
• Limitation of the role of the endocrine system in explaining behaviour (AO3)

  • Biologically reductionist
  • The notion that biological structures underpin human behaviour is BR
  • It reduces human behaviour and cognitive processes to biological components (a biological/molecular level of explanation)
  • Reducing behaviour down to hormonal components may reduce the 'human' of psychology and may therefore limit our understanding of the wider contextual explanations of psychological behaviours
  • Therefore may suggest that the endocrine system can only account for SOME influence over behaviours due to the biological root of hormones but there may be wider factors in certain behaviours beyond a biological level (requiring a psychological or social level of explanation)
  • E.g. gender roles can be defined by hormones but may also be reinforced by societal expectations and representations (socialised)
• Limitation in measuring influence of neurochemistry (AO3)

  • Can be alternatively argued that neurochemicals within the endocrine system are tools to make a behaviour occur
  • This is alternative to the endocrine system being the cause, the release of hormones may merely be a response to an external stimulus in which our body responds through regulation
  • Therefore lacks internal validity as a cause and effect relationship cannot be established, only correlational
  • E.g. Relationship between increased relationship intensity and oxytocin levels (KOSFELD) however oxytocin does not cause the relationship to be more intense
  • Equally possible as forming a relationship may result in higher levels of OXY
• Strength, practical app. (AO3)

  • Oxytocin as a hormone released from pituitary gland
  • Implicated in allowing humans to experience empathy and share feelings of others
  • Individuals with ASD tend to suffer from a lack of this, often have low levels of oxytocin
  • May therefore suggest a connection between the two, establishing a biological explanation for a lack of social cognition within ASD sufferers