The Function of the Endocrine System (AQA A Level Psychology): Revision Note

Glands & hormones

• A hormone is a chemical that is secreted by the endocrine glands into the bloodstream, which then distributes it around the body

• The major gland which regulates hormones is the pituitary gland, located at the base of the hypothalamus in the brain

• Hormones generally act more slowly than neurotransmitters, but their effects can be longer-lasting and, in some cases, span developmental stages such as puberty

• Hormones have different effects on the body and behaviour depending on the nature of the hormone itself

Hormones secreted by the pituitary gland

• Adrenocorticotropic Hormone (ACTH) - triggers the adrenal glands to produce cortisol and androgens (a group of male sex hormones)

• Follicle-stimulating hormone (FSH)- plays a role in sexual development and reproduction in both males and females

• Luteinising hormone (LH ) - encourages ovulation and hormones needed to support pregnancy

• Oxytocin - released during childbirth, breastfeeding and social bonding; encourages attachment between mother and baby

• Thyroid-stimulating hormone (TSH) - triggers the release of thyroxine from the thyroid gland, which regulates the body's metabolism

Sex hormones

• Testosterone - the male sex hormone, produced primarily by the testes

  • Controls primary and secondary sexual characteristics

  • Regulates milestones such as puberty and sperm production

• Oestrogen - the female sex hormone, produced primarily by the ovaries

  • Controls primary and secondary sexual characteristics

  • Regulates milestones such as puberty, the menstrual cycle and menopause

• The slow release of testosterone and oestrogen during puberty is a clear example of hormones producing long-term, developmental effects

Hormones secreted by other endocrine glands

• Melatonin - secreted by the pineal gland

  • Regulates the sleep/wake cycle and is sensitive to light levels detected via the suprachiasmatic nucleus

• Cortisol - secreted by the adrenal cortex

  • Known as the stress hormone as it plays a key role in the body's response to prolonged or chronic stress

• Adrenaline - secreted by the adrenal medulla

  • Active during the fight-or-flight response to immediate danger

• Thyroxine - secreted by the thyroid gland

  • Regulates metabolism and growth