d clinical practice. Question Answer What is the WHO classification of tumors of endocrine organs based on? The WHO classification of tumors of endocrine organs is based on histopathological features, including cell type, differentiation, molecular
re most commonly classified under the WHO system? Commonly classified tumours include thyroid carcinomas (papillary, follicular, medullary, anaplastic), neuroendocrine tumours of the pancreas, adrenal cortical tumours, and parathyroid neoplasms. What role does molec
n temporarily. Example: During ovulation, estrogen increases GnRH and LH secretion. In virtual labs: Modulating hormone levels demonstrates how feedback loops stabilize endocrine functions. Disruptions can lead to exaggerated or diminished res
renal medulla neuroendocrine origin; nested or Zellballen pattern, with chromaffin cells containing catecholamines. Histopathological Features of Neuroendocrine Tumors Neuroendocrine tumors display distinc
uence the pituitary gland, which in turn secretes hormones affecting other glands. Negative Feedback : Elevated levels of hormones inhibit further secretion to maintain homeostasis. Examples of Feedback Loops Thyroid hormone regulation: Hypothalamus releases thyrotropin-releasing hormone (TRH), s
ated in the brain, it links the nervous system and endocrine system, releasing releasing hormones that regulate pituitary secretion. Thyroid Gland: Produces thyroid hormones (T3 and T4) that regulate metabolism, energy generation,
ne system’s fundamental concepts. This knowledge foundation will help you approach questions with confidence. What Is the Endocrine System? The endocrine system is a network of glands that produce and secrete hormones directly
idase) B) Thyroglobulin synthase C) Deiodinase D) Iodide transporter (NIS) Answer: A) TPO (Thyroid Peroxidase) Explanation: Thyroid peroxidase catalyzes iodide oxidation and subsequent iodination of tyrosine residues, a critical step in thyroid hormone bio
tasis. Stimulus triggers hormone release. Hormone exerts its effect on target tissues. Feedback mechanisms inhibit or stimulate further hormone release. 3. Mechanisms of Hormone Action Understanding how hormon
