Endocrine Glands

• Which organs are classified as secondary endocrine glands?

  GI tract, kidney, heart, thymus, liver, adipocytes, bone, skin
• What are the primary endocrine organs listed in the material?

  Hypothalamus, pituitary, pineal, thyroid, parathyroid, adrenal cortex and medulla, endocrine pancreas, ovaries, placenta, testes
• Where is the hypothalamus located in relation to the pituitary gland?


  Above the pituitary gland
• What is the pituitary gland also known as?

  Adenohypophysis and neurohypophysis
• What is the role of hypothalamic-releasing factors?

  They control the secretion of anterior pituitary hormones
• What is meant by the term "endocrine axis"?

  Interactions between the hypothalamus, pituitary, and peripheral endocrine glands
• What hormones are secreted by the posterior pituitary gland?

  Arginine vasopressin (AVP) and oxytocin
• What is the primary action of vasopressin (AVP)?

  To increase water reabsorption in the kidneys
• What triggers the release of oxytocin?

  Suckling and cervical stimulation during parturition
• What is melatonin and where is it secreted from?

  Melatonin is secreted by the pineal gland
• What is the role of melatonin in the body?

  It regulates circadian rhythms and promotes sleep
• What are the main thyroid hormones produced by the thyroid gland?

  Thyroxine (T4) and tri-iodothyronine (T3)
• What is the function of calcitonin?

  To lower plasma calcium levels
• What is the primary action of thyroid hormones?

  To increase metabolism in the body
• What is the relationship between T3 and T4?

  Most T4 is converted to T3 in the periphery
• What are the effects of thyroid hormones on growth and development?

  They are particularly important for normal development and maturation of the CNS
• What are the main actions of insulin?

  • Increases glucose uptake in target tissues
  • Promotes glucose utilization
  • Has anabolic effects on metabolism
• What are the counter-regulatory hormones to insulin?

  • Glucagon
  • Adrenaline
  • Cortisol
  • Growth hormone
• What is the significance of the endocrine axis?

  • Maintains physiological homeostasis
  • Involves feedback regulation of hormone secretion
  • Direct influences between hypothalamus, anterior pituitary, and peripheral endocrine glands
• What is the role of thyroid peroxidase (TPO) in thyroid hormone synthesis?

  TPO catalyzes the iodination and coupling of tyrosine residues
• What is the chemical structure of thyroxine (T4)?

  T4 is composed of two di-iodotyrosine molecules
• What is the primary effect of calcitonin in calcium homeostasis?

  It decreases plasma calcium levels
• What is the primary function of the adrenal cortex hormones?

  To regulate metabolism, immune response, and stress response
• What is the primary function of the adrenal medulla hormones?

  To prepare the body for fight or flight response
• What is the role of the hypothalamic-pituitary-adrenal axis?

  It regulates the body's response to stress
• What is the significance of feedback regulation in the endocrine system?

  It maintains homeostasis by regulating hormone levels
• What is the role of the pancreas in the endocrine system?

  It produces hormones like insulin and glucagon that regulate blood sugar
• What is the primary action of glucagon?

  To increase blood glucose levels
• What is the role of adrenaline in the body?

  To prepare the body for fight or flight response
• What is the role of cortisol in the body?

  To regulate metabolism and immune response during stress
• What is the role of growth hormone in the body?

  To stimulate growth and cell reproduction
• What are the effects of thyroid hormones on carbohydrate metabolism?

  They increase the metabolism of carbohydrates
• What is the role of the hypothalamus in hormone regulation?

  It secretes factors that regulate hormone release from the anterior pituitary
• What is the significance of the anterior pituitary in the endocrine system?

  It secretes tropic hormones that act on peripheral endocrine glands
• What is the role of the pineal gland in the endocrine system?

  It secretes melatonin, which regulates sleep and circadian rhythms
• What is the role of the parathyroid hormone (PTH)?

  To increase plasma calcium levels
• What is the role of the adrenal cortex hormones in the body?

  To regulate metabolism, immune response, and stress response
• What is the role of the adrenal medulla hormones in the body?

  To prepare the body for fight or flight response
• What is the primary function of the hypothalamic-pituitary-adrenal axis?

  To regulate the body's response to stress
• What is the role of calcitonin in calcium homeostasis?

  To decrease plasma calcium levels