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Endocrinology key concepts

5 revision pages for Endocrinology, each with the key facts, a memory aid where one helps, and the exam traps.

  1. Aldosterone action on the distal nephron

    Aldosterone is a steroid hormone that makes the late nephron (the later part of the kidney's filtering tube) keep sodium and lose potassium, so water follows.

  2. Arcuate nucleus: POMC neurones versus NPY and AgRP neurones

    In the arcuate nucleus (a cluster of neurones within the hypothalamus), neurones making POMC (a precursor protein) suppress appetite, while neuropeptide Y (NPY) and agouti-related peptide (AgRP) neurones stimulate it.

  3. Ghrelin, the pre-meal hunger hormone

    Ghrelin, a peptide hormone (a short chain of amino acids), is released from an empty stomach and stimulates appetite, the urge to eat, so hunger rises before a meal.

  4. Posterior pituitary: oxytocin and ADH made in the hypothalamus

    The posterior pituitary stores and releases oxytocin (which acts on the breast and uterus) and antidiuretic hormone, ADH (which acts on the kidney); the hypothalamus makes both.

  5. Steroid versus peptide hormones: receptors and mechanism of action

    Fat-soluble steroid hormones act on receptors inside the cell to change gene transcription, whereas water-soluble peptide hormones act on receptors on the cell surface.

Practice Endocrinology questions