Endocrine System

• (AO1) Define a hormone and a gland

  Hormone = chemical substance that helps to regulate processes in the body. Hormones are secreted by glands to travel to their target organs in the bloodstream (different hormones produce different effects or behaviours)

  Gland = an organ which facilitates the release of hormones
• (AO1) Define the endocrine system

  Works alongside the nervous system. It is a network of glands across the body that secrete chemical messages called hormones. It uses blood vessels to transmit information.
• (AO1) Explain the effect of the hypothalamus

  Stimulates and controls the release of hormones from the pituitary gland
• (AO1) State the hormones released by the pituitary gland (master gland) and their effects

  Main hormone = anterior = ACTH

  Effects = stimulates the adrenal cortex and the release of cortisol during the stress response.

  Second hormone = posterior = oxytocin

  Effect = responsible for uterus contractions during childbirth
• (AO1) State the hormone released by the pineal gland and its effect

  Main hormone = melatonin

  Effect = responsible for important biological rhythms, including the sleep-wake cycle
• (AO1) State the hormone released by the thyroid gland and its effect

  Main hormone = thyroxine

  Effect = responsible for regulating metabolism
• (AO1) State the hormones released by the adrenal gland and its effects

  Main hormone = adrenal medulla = adrenaline + noradrenaline

  Effect = key hormones in the fight or flight response

  Second main hormone = adrenal cortex = cortisol

  Effect = stimulates the release of glucose to provide body with energy, suppressing the immune system.
• (AO1) State the hormone released by the ovaries and its effect

  Main hormone = oestrogen

  Effect = controls the regulation of the female reproductive system, including menstrual cycle + pregnancy
• (AO1) State the hormone released by the testes and its effect

  Main hormone = testosterone

  Effect = responsible for the development of male sex characteristics during puberty + promoting muscle growth
• (AO1) Complete the diagram attached

  Diagram:

  A) Pineal Gland

  B) Testicles

  C) Ovary

  D) Hypothalamus

  E) Pituitary gland

  F) Thyroid gland

  G) Adrenal gland

  
• (AO1) What did Dabbs et al do?

  Provided evidence for the role of hormones in behaviour.

  
  

  Found high testosterone levels in men convicted of domestic violence.

  High testosterone may results from prison environment and violence, not the cause.

  
  

  Endocrine system may not fully explain the behaviour

  
  

  Alternative: men's free choice influenced their decision to commit the crime, separately from their hormone levels
• (AO1) How does oxytocin (anorexia nervosa) relate to hormones?


  Oxytocin = hormone released by pituitary gland.

  
  

  Can greatly affect behaviour. Elicits feelings of relaxation, bonding in couples / bonding in infants and caregivers.

  
  

  Research has also shown that oxytocin can have a calming effect on patients with anorexia nervosa.

  
  

  In a small-scale study, patients reported a reduction on the focus on their body fat and negative images of food after they were given oxytocin.