Histology of the Endocrine Organs

The endocrine system

Endocrine cells:Endocrine glandsEmbedded in other organs (pl. enteroendocine system)

Regulation: synthesis of chemical transmitter molecules (hormones)Endocrine glands:

No excretory ductRelease of secretory product directly to the blood stream

Target organs:ReceptorsSignal transduction pathways

The endocrine glands

Pituitary gland (hypophysis)Thyroid gland (glandula thyroidea)Parathyroid gland (glandula parathyroidea)Adrenal/suprarenal gland (glandula suprarenalis)Pineal gland (corpus pineale)Pancreas: Langerhans-islets (insular apparatus)Ovarium: yellow body (corpus luteum)Testis: Leydig cells

The developmental origin of the endocrine glands

Ectoderm:Neuroectoderm:

neurohypophysiscorpus pineale

Neural crest:gl. thyroidea -parafollicular cells,gl. suprarenalis -medulla

Epithelium:Rathke s pouch: adenohypophysis

Mesoderm:gl. suprarenalis -cortex

Endoderm:Epithelium: gl. parathyroideaLangerhans islets

Slide 67, hypophysis, H&E, 4x

Neurohypophysis:Neurohypophysis:pars nervosapars nervosa

Adenohypophysis:Adenohypophysis:pars intermediapars intermedia

Adenohypophysis:Adenohypophysis:pars distalispars distalis

Slide 67, hypophysis pars nervosa, H&E, 40x

capillariescapillaries(fenestrated(fenestratedendothelium)endothelium)

pituicytespituicytes

endothelialendothelialcellcell

axons(hypothalamo-hypophyseal tract)

Slide 67, hypophysis pars intermedia, H&E, 40x

cyst filled with colloidcyst filled with colloid

simple cuboidal epitheliumsimple cuboidal epithelium

Slide 67, hypophysis pars distalis, H&E, 40x

acidophil cellsacidophil cellsbasophil cellsbasophil cells

chromophobe cellchromophobe cell

n. paraventricularis

n. supraopticus

axons(hypothalamo-hypophyseal tract)

optic tract

3rdventricle

Slide 85, hypothalamus, oxytocin immunocytochemistry, 4x

Slide 85, n. supraopticus, oxytocin immunocytochemistry, 40x

Slide 68, thyroid gland, H&E, 4x

connective tissue septum

follicles

Slide 68, thyroid gland, H&E, 40x

folliclefollicularepithelialcells

colloid(thyroglobulin)

capillary

Slide 69, parathyroid gland, H&E, 10x

oxyphil cellsoxyphil cells

chief cellschief cells

capillariescapillaries

Slides 69, parathyroid gland, H&E, 40x

oxyphil cellsoxyphil cells

chief cellschief cells

adipocytesadipocytes

Slide 70, adrenal gland, H&E, 4x

medullamedulla

cortexcortex

capsulecapsule

z. glomerulosaz. glomerulosa

z. reticularisz. reticularis

z. fasciculataz. fasciculata

Slide 70, adrenal gland - cortex, H&E, 10x

capsulecapsule

Slide 70, zona glomerulosa, H&E, 40x

endocrineendocrinecellscells

Slide 70, zona fasciculata, H&E, 40x

sinusessinuses

endocrineendocrinecellscells

Slides 70, zona reticularis, H&E, 40x

sinusessinuses

endocrine cellsendocrine cells

Slide 70, adrenal medulla, H&E, 40x

sinusessinuses

arteriolearteriole

chromaffin cellschromaffin cells

Slide 50, pancreas, H&E, 10x

exocrineexocrinepancreaspancreas

islets of Langerhansislets of Langerhans

septumseptum

lobuluslobulus

Slide 50, pancreas, H&E, 40x

islet of Langerhansislet of Langerhans

capillarycapillary

Slide 71, corpus luteum, H&E, 4x

ovarian cortexovarian cortex

corpus luteumcorpus luteum

folliclesfollicles

Slide 71, corpus luteum, H&E, 10x

thecatheca--lutein cellslutein cells

granulosagranulosa--lutein cellslutein cells

Slide 71, corpus luteum, H&E, 40x

thecatheca--lutein cellslutein cells

granulosagranulosa--lutein cellslutein cells