2. ADRENAL & PARATHYROID
Dr Iram Tassaduq

3. ADRENAL (SUPRARENAL ) GLAND
Lies on upper pole of each kidney
Comprised of two zones
outer cortex
inner medulla
Develops from intermediate mesoderm and neural crest cells

6. INTRODUCTION
The adrenal gland is encased in a connective tissue capsule that extends septae into the substance of the gland. The organ is richly vascularized and capsular blood vessels, nerves and lymphatics penetrate along with the connective tissue septae.

7. CORTEX zona glomerulosa - thin, outermost zone
zona fasiculata - thick, middle zone
zona reticularis - thin, inner zone

8. ZONA GLOMERULOSA
Composed of columnar or pyramidal cells arranged as rounded or arched cords
Occupy 15% of gland volume

9. ZONA GLOMERULOSA

10. ZONA FASICULATA Cells are arranged in straight cords. 1-2 cells thick
Cords run at right angles to the surface of organ and have capillaries between them
Occupy 65% of gland volume

11. ZONA FASICULATA

12. ZONA RETICULARIS Polyhedral cells with lipid droplets Form 7% of gland
Appears vacuolated in histological preparations
Cells are smallest in size

13. ZONA RETICULARIS

14. ADRENAL MEDULLA
Composed of cords or clumps of cells called chromaffin cells. These can acquire brown colour which is due to oxidation of catecholamines
Modified postganglionic sympathetic neurons

15. ADRENAL MEDULLA

16. FUNCTIONS OF ADRENAL GLAND

17. PARATHYROID GLAND Two pairs in mammals
Embedded within thyroid gland substance
C.T. capsule is thin

20. PRINCIPAL CELLS/ CHIEF CELLS
More numerous of parenchymal cells
Small, polyhedral cells, of 7-10 um in diameter
Rounded, vesicular nuclei
Responsible for secretion of PTH
chief cells

22. OXYPHILL CELLS Constitute a minor portion of parenchyma
Found singly or in clusters
More rounded & larger than principal cells
Distinctly acidophilic cytoplasm
No secretory activity