ENDOCRINE GLANDS II

WRITTEN BY RAYAN S. ALBALLAA

PARATHYROID GLAND

 LOCATION :  THERE ARE 4 PARATHYROID GLANDS ATTACHED TO THE POSTERIOR SURFACE OF THE THYROID GLAND , TWO ON EACH THYROID LOBE .

 EACH PARATHYROID IS ENCLOSED IN A CT CAPSULE .

PARATHYROID GLAND

 THE CELLS OF THE PARATHYROID FORM CLUSTERS OR CORDS OF EPITHELIAL CELLS AROUND FENESTRATED CAPILLARIES SUPPORTED BY RETICULAR FIBERS .

 SECRETES PARATHYROID HORMONE WHICH MAINTAINS Ca++ LEVEL BY ACTING ON BONE , KIDNEY , & INTESTINE .

PARATHYROID GLAND



COINTAINS TWO TYPES OF CELLS :-

 

1.CHIEF CELLS

ARE NUMEROUS , SLIGHTLY EOSINOPHILIC ( ACIDOPHIHLIC ) SMALL CELLS WITH LARGE NUCLEI . HAVE SECRETORY GRANULES CONTAINING PARATHYROID HORMONE .

2.OXYPHIL CELLS

ARE FEWER , LARGER , ACIDOPHILIC , & MORE DEEPLY STAINED WITH EOSIN THAN CHIEF CELLS . THEY HAVE MORE MITOCHONDRIA THAN CHIEF CELLS . THEIR FUNCTION IS UNKNOWN .

ADRENAL GLAND ( SUPRARENAL )

 THERE’S A LEFT & A RIGHT ADRENAL GLANDS LOCATED ON THE SUPERIOR POLE OF EACH KIDNEY EMBEDDED IN FAT & COVERED BY A CT CAPSULE .

ADRENAL GLAND



CONSISTS OF :-

1.

2.

OUTER CORTEX INNER MEDULLA

ADRENAL CORTEX



THE CORTEX CONSISTS OF 3 ZONES :

   1. ZONA GLOMERULOSA ( OUTERMOST ) 2. ZONA FASCICULATA ( MIDDLE ) 3. ZONA RETICULARIS ( INNERMOST )

ADRENAL CORTEX

     THE CELLS OF ALL ZONES OF THE CORTEX HAVE THE FEATURES OF STEROID SECRETING CELLS : SPHERICAL MITOCHONDRIA EXTENSIVE SER NO SECRETORY GRANULES ( VESICLES ) LIPID DROPLETS IN THE CYTOPLASM  THEY SYNTHESIZE & SECRETE STEROID HORMONES .

ZONA GLOMERULOSA ( OUTERMOST ZONE )

      SMALL ACIDOPHILIC COLUMNAR CELLS DARK-STAINING NUCLEI SOME LIPID DROPLETS IN THE CYTOPLASM THE CELLS FORM CORDS OR CLUSTERS ( GROUPS ) EXTENSIVE SMOOTH ENDOPLASMIC RETICULUM SECRETES MINERALOCORTICOIDS ( ALDOSTERONE ) 

NOTE : WRONG STATEMENT IN THE BOOK ABOUT RER P.318

ZONA FASCICULAT (MIDDLE ZONE )

        LARGEST ZONE OF THE CORTEX THE CELLS FORM STRAIGHT RADIAL COLUMNS THE CELLS ARE CALLED SPONGIOCYTES MANY LIPID DROPLETS IN CYTOPLASM LIGHTLY ACIDOPHILIC ( VACUOLATED CYTOPLASM ) THE CELLS ARE LARGER THAN THOSE OF GLEOMERULOSA CONTAINS SINUSOIDAL CAPILLARIES SECRETES GLUCOCORTICOIDS

ZONA RETICULARIS ( INNERMOST ZONE )

      THE CELLS ARE SMALLER THAN THOSE OF FASCICULATA THE CELLS FORM ANASTMOSING CORDS DARKLY STAINING ACIDOPHILIC CELLS FEWER LIPID DROPLETS THAN FASCICULATA SECRETES SEX HORMONES ( ANDROGENS ) MAY SECRETE GLUCOCORTICOIDS

ADRENAL MEDULLA

 THE ADRENAL MEDULLA IS NOT SEPARATED FROM THE CORTEX BY CT  THE CELLS OF THE ADRENAL MEDULLA HAVE THE FEATURES OF PROTEIN SECRETING CELLS  AS IN THE CORTEX , THE CAPILLARIES OF THE MEDULLA ARE FENESTRATED

ADRENAL MEDULLA



THE MEDULLA CONTAINS :-

 MODIFIED SYMPATHETIC GANGLION CELLS ( WITHOUT AXONS OR DENDRITES ) CALLED

CHROMAFFIN CELLS

 THE CHROMAFFIN CELLS SYNTHESIZE & STORE THE HORMONE EPINEPHRINE & NOREPINEPHRINE IN CYTOPLAMIC GRANULES WHICH STAIN BROWN WHEN FIXED IN SALTS OF CHROMIC ACID  SYMPATHETIC GANGLION CELLS ARE ALSO FOUND