1 / 58

Endocrine system

Explore the intricate structure and functions of endocrine system components like the pituitary gland, hypothalamus-pituitary axis, thyroid, parathyroid, pancreas, and adrenal glands. Understand the synthesis and secretion of hormones, cell types, histology, and hormone regulation in detail.

henrym
Download Presentation

Endocrine system

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Endocrine system

  2. Cells, tissues and organs that synthesize and secrete hormones • Bloodstream • No excretory ducts

  3. The pituitary gland (Hypophysis cerebri) Adenohypophysis Pars distalis, Pars tuberalis, Pars intermedia Neurohypophysis Median eminence, Infundibulum, Pars nervosa

  4. Pars distalis /anterior • Chromophobe cells • Chromophil cells

  5. Chromophobes: • Non-granular, homogenous cytoplasm • Cell boundaries indistinct

  6. Chromophils Acidophils: • Granular Cytoplasm • Cell outlines distinct • Lie in the vicinity of sinusoidal capillaries Basophils: • Granular cytoplasm • Vary in shape

  7. Pars intermedia: • Colloid filled cysts • Follicles with basophilic cells

  8. Hypophysis cerebri

  9. Pars nervosa: • Unmyelinated axons • Supraoptic and paraventricular nuclei • Hypothalamohypophyseal tract • Pituicytes are neuroglial cells • Herring bodies (terminal ends of unmyelinated axons)

  10. The hormones • Pars distalis / Anterior • Acidophils: GH, Prolactin • Basophils: ACTH, TSH, LH, FSH (ICSH) • Chromophobes: Give rise to chromophils /resting cells • Pars intermedia • MSH • Pars posterior/ Neurohypophysis • Supraoptic nucleus -Vasopressin (ADH) • Paraventricular nucleus - Oxytocin

  11. Pars intermedia Pars nervosa Pars distalis

  12. Acidophils Basophils Chromophobes

  13. Pituicytes

  14. Hypophysis cerebri

  15. Thyroid • Covered by capsule • Connective tissue septa , lobules • Colloid filled follicles, lined by simple cuboidal cells • Thyroglobulin (colloid) • Hormones: T3 and T4

  16. Parafollicular cells (clear or C cells) • Lighter staining cytoplasm • Bigger in size, oval in shape • Present between follicular cells • Hormone: Calcitonin

  17. Colloid????? - Thyroglobulin + iodine

  18. Parafollicular cells / C cells • Calcitonin -Released when blood calcium level is more (> 5-6mg/100ml) -Helps decrease the blood calcium level by acting on bone, kidney and intestine

  19. Parathyroid • Associated with the thyroid • Generally four in number • Cells arranged in clumps

  20. Two types of cells Chief (principal) cells • Round, Pale, slightly acidophilic cytoplasm • Most numerous • Small dark-staining nuclei Oxyphilic cells • Larger in size, less in number • Strongly acidophilic

  21. Hormones Chief cells: Parathormone • Released when blood calcium level is decreased (< 5-6mg/100ml) • Increases blood calcium level by acting on bone, kidney and intestine Oxyphil cells: not known

  22. Thyroid and parathyroid

  23. Thyroid and parathyroid

  24. Micro Structural Anatomy of pancreas

  25. Covered with a very thin layer of loose connective tissue capsule. Thin septa arising from capsule and divide the gland into many lobules. Inter lobular connective tissue contains large ducts, blood vessels and nerve fibers. Interlobular- surrounds the acini & Islets

  26. It is the serous gland. Secretory units are acinar or tubuloacinar in shape. Formed by simple epithelium of pyramidal serous cells. Exocrine Pancreas

  27. Duct system of exocrine part Main Pancreatic Duct Interlobular Duct Intralobular Duct Intercalated Duct Centro Acinar

  28. Diffuse organ & secretes hormone that regulates the glucose level Islets of Langerhans scattered throughout organ. 1 – 3 million Polygonal cells are arranged in short, irregular cords Endocrine pancreas

  29. A- alpha-20%, Densely packed cytoplasm B- beta-70%, dense polyhedral core and pale matrix. D- delta- 5-10%, Secretory granules large than A & B cells. Minor cells- PP & D1 cells

  30. Pancreas Pancreatic acini Islets of Langerhans Interlobular connective tissue

  31. Pancreas- magnified Bipolar stained pancreatic acini Islets of Langerhans

  32. SUPRARENAL GLAND

  33. SUPRARENAL GLAND • A pair of endocrine glands • Situation:-on the posterior abdominal wall over the upper pole of the kidneys behind the peritoneum • Shape:-right suprarenal gland – triangular left suprarenal gland -semilunar

  34. Histology • Covered by connective tissue capsule • Septa from capsule extend into the gland substance • Parts:-superficial-cortex (9/10) deeper-medulla (1/10)

More Related