7/29/2019 Histology of Thyroid and Suprarenal Glands

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Created by QI

Histology of thyroid gland

Cell Follicular Cells Parafollicular Cells

Size/Shape Smaller, cuboidal cells, squamous during rest, columnar during

active

Larger

Nuclei Central roundedCytoplasm Basophilic Pale (clear cells)

Resting

Site

Basal surface resting on basement membrane, apical towards

lumen

Basal surface resting on basement membrane, but apical never

towards lumen

Organelles Polypeptide secreting cells features:

-Mitochondria

-Golgi complex is supranuclear-rER

-Small secretory granules are apical towards lumen

-Lysosomes

-Phagosomes

Polypeptide secreting cells features:

-Mitochondria

-rER-Golgi complex is infranuclear

-Small dense secretory granules towards capillary bed

Function Secrete thyroid hormones Secrete calcitonin

Histology of Suprarenal glands

Part (Beside

Stroma)

Cortex

-Mesodermal in origin (coelomic mesoderm)

-Same origin as endocrine cells of gonads

Medulla

-Ectodermal in origin (neural crest)

-Same origin as sympathetic system

-3 populations of parenchymal cells:

1) Chromaffin cells

2) Sympathetic ganglion cells3) Lymphocyte-like cells

Volume Zona Glomerulosa Zona Fasciculata Zona Reticularis

15% 65% 7%

Shape Columnar/Pyramidal Polyhedral Large ovoid

Arrangement Closely packed, rounded or Cords 1 or 2 cells, thick, Irregular cords anastomose Rounded groups or short cords,

7/29/2019 Histology of Thyroid and Suprarenal Glands

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Created by QI

arched clusters surrounded

by BC

separated by longitudinally

arranged fenestrated BC

together enclosing

fenestrated BC in between

intimately related to BC

Nuclei Dense, basal Pale, large, vesicular Some cells near suprarenal

medulla are dark cells with

pyknotic nuclei, suggesting

they are degenerating cells

Large spherical

Cytoplasm Acidophilic, slightly

vacuolated

Acidophilic, numerous

vacuoles (spongiocytes)

Small, acidophilic Pale basophilic

Lipid

DropletFew Numerous (cholesterol and

ascorbic acid)

Few

Organelles Steroid secreting cells

features:-Smooth ER

-Mitochondria with tubular

cristae

Steroid secreting cells

features

Steroid secreting cells

features (lipofuscinpigments are characteristic

in this layer)

Polypeptide secreting cells features:

-rER

-Mitochondria

-Golgi complex

-Secretory granules containing

catecholamines

NEP cells

-Large granules-Eccentric electron dense core

within limiting membrane of

granules

EP cells

-Small

-Less dense granules

-Their contents fill the granulesFunction Secrete mineralcorticoids

mainly aldosterone which

maintains electrolyte and

water balance

Secrete glucocorticoids Secretes androgens and

few glucocorticoids

Secretes catecholamines