Endo, Urinary and Repro AI ILO Answers

• Hypothalamic-Pituitary-Adrenal (HPA) Axis


  A complex set of direct influences and feedback interactions among three endocrine glands: the hypothalamus, the pituitary gland, and the adrenal glands
• HPA Axis Function


  1. Hypothalamus releases corticotropin-releasing hormone (CRH)

  2. Pituitary Gland releases adrenocorticotropic hormone (ACTH) in response to CRH

  3. Adrenal Glands produce cortisol in response to ACTH

  4. Cortisol provides negative feedback to the hypothalamus and pituitary to regulate CRH and ACTH production
• Adrenal Medulla


  Inner part of the adrenal gland, produces catecholamines (epinephrine and norepinephrine)
• Adrenal Medulla


  • Involved in the 'fight or flight' response, increasing heart rate, blood pressure, and blood glucose levels
• Adrenal Cortex


  Outer part of the adrenal gland, produces corticosteroids (aldosterone, cortisol, and androgens)
• Adrenal Cortex


  • Aldosterone regulates sodium and potassium balance
  • Cortisol manages stress response, metabolism, and immune response
• Norepinephrine and Epinephrine


  1. Synthesis: Derived from the amino acid tyrosine in the adrenal medulla

  2. Secretion: Released in response to stress

  3. Action: Bind to adrenergic receptors, affecting cardiovascular and metabolic systems
• Aldosterone


  1. Synthesis: Produced in the zona glomerulosa of the adrenal cortex

  2. Secretion: Stimulated by angiotensin II, potassium levels, and ACTH

  3. Action: Increases sodium reabsorption and potassium excretion in the kidneys
• Cortisol and Cortisone


  1. Synthesis: Produced in the zona fasciculata of the adrenal cortex

  2. Secretion: Stimulated by ACTH

  3. Action: Influences metabolism, reduces inflammation, and suppresses immune response
• Insulin


  1. Synthesis: Produced by β-cells in the pancreas

  2. Secretion: Released in response to high blood glucose levels

  3. Action: Promotes glucose uptake by cells, glycogenesis, and lipid storage
• Glucagon


  1. Synthesis: Produced by α-cells in the pancreas

  2. Secretion: Released in response to low blood glucose levels

  3. Action: Stimulates glycogenolysis and gluconeogenesis in the liver
• Addison's Disease


  Insufficient production of cortisol and aldosterone, symptoms include fatigue, low blood pressure, and hyperpigmentation
• Cushing's Syndrome


  Excess cortisol production, symptoms include weight gain, hypertension, and glucose intolerance
• Diabetes Mellitus


  Insufficient insulin production or action, symptoms include hyperglycemia, polyuria, polydipsia, and weight loss
• Hypoglycemia


  Excessive insulin production, symptoms include sweating, tremors, and confusion
• Hormone


  A chemical messenger produced by endocrine glands, transported by the bloodstream to target organs, and regulates physiological functions
• Hormone Classifications


  • Peptide Hormones (e.g. insulin, glucagon)
  • Steroid Hormones (e.g. cortisol, aldosterone, sex hormones)
  • Amino Acid Derivatives (e.g. epinephrine, norepinephrine, thyroid hormones)
• Pituitary Gland Location


  Situated at the base of the brain, within the sella turcica of the sphenoid bone
• Pituitary Gland Divisions


  • Anterior Pituitary (Adenohypophysis)
  • Posterior Pituitary (Neurohypophysis)
• Anterior Pituitary Hormones


  • Growth Hormone (GH)
  • Thyroid-Stimulating Hormone (TSH)
  • Adrenocorticotropic Hormone (ACTH)
  • Prolactin (PRL)
  • Follicle-Stimulating Hormone (FSH) and Luteinizing Hormone (LH)
• Posterior Pituitary Hormones


  • Oxytocin
  • Vasopressin (ADH)
• Anterior Pituitary


  Glandular tissue, produces and secretes hormones in response to hypothalamic signals
• Posterior Pituitary


  Neural tissue, stores and releases hormones produced by the hypothalamus
• Pineal Gland


  Located in the brain, produces melatonin and regulates sleep-wake cycles
• Thyroid Gland


  Located in the neck, around the trachea, produces thyroid hormones (T3, T4) and calcitonin
• Parathyroid Gland


  Located on the posterior surface of the thyroid gland, produces parathyroid hormone (PTH) and regulates calcium levels
• Adrenal Gland


  Located above the kidneys, produces corticosteroids and catecholamines
• Pancreas


  Located in the abdominal cavity, behind the stomach, produces insulin, glucagon, and digestive enzymes
• Endocrine Gland Cellular Organisation

  • Clumps/Clusters (e.g. Islets of Langerhans in the pancreas)
  • Follicles (e.g. thyroid gland)
  • Cords (e.g. adrenal cortex)
• Thyroid Gland Anatomy


  Located in the anterior neck, two lobes connected by an isthmus, follicles filled with colloid containing thyroglobulin
• Thyroid Hormone Synthesis


  1. Iodine Uptake

  2. Thyroglobulin Synthesis

  3. Iodination

  4. Coupling

  5. Secretion
• Thyroid Hormone Mechanism of Action

  T3 and T4 bind to nuclear receptors, regulate gene expression, and increase metabolic rate
• Hypothalamic-Pituitary-Thyroid (HPT) Axis


  1. Hypothalamus releases thyrotropin-releasing hormone (TRH)

  2. Pituitary releases TSH in response to TRH

  3. Thyroid Gland produces T3 and T4 in response to TSH

  4. T3 and T4 provide negative feedback to inhibit TRH and TSH release
• Hyperthyroidism


  Symptoms include weight loss, increased heart rate, heat intolerance, caused by conditions like Graves' disease and thyroid nodules
• Hypothyroidism


  Symptoms include weight gain, fatigue, cold intolerance, caused by conditions like Hashimoto's thyroiditis and iodine deficiency
• Parathyroid Hormone (PTH)


  Increases blood calcium levels by stimulating bone resorption, increasing renal calcium reabsorption, and enhancing intestinal calcium absorption
• Vision


  The long-term goal and aspirations of the business
• Mission


  The purpose and core values of the business
• Strategy


  The plan to achieve the vision and mission
• Porter's 5 Forces


  • Competitive Rivalry
  • Threat of New Entrants
  • Bargaining Power of Suppliers
  • Bargaining Power of Customers
  • Threat of Substitutes