Endocrine histology pptx - د. حيدر الكفائي

JABIR IBN HAYYAN MEDICAL UNIVERSITYCOLLEGE OF MEDICINE DEPARTMENT OF HUMAN ANATOMY

Histology of Endocrine System
Lecture By;
Dr. Hayder ALKifaee
20/4/2017

Endocrine Glands& Organs Containing Endocrine Cells

Primary Endocrine Organs

• Pituitary Gland (Hypophysis Cerebri)
• Pineal Gland (Epiphysis Cerebri)
• Thyroid Gland
• Parathyroid Gland
• Adrenal Gland

Secondary Endocrine Organs

• Kidney
• Testes
• Ovaries
• Pancreas
• Stomach
• Intestines
• Thymus
• Heart
• Placenta

Typical Endocrine Glands
• Pituitary Gland (Hypophysis Cerebri)
• Pineal Gland (Epiphysis Cerebri)
• Thyroid Gland
• Parathyroid Gland
• Adrenal Gland

Scattered Endocrine Masses

Islets of Langerhans
Corpus luteum
Interstitial cells of Leydig
Placental lactogen secreting cells
Chorionic gonadotropin secreting cells
Juxtaglomerular cells

Isolated Endocrine Cells (Diffuse Neuroendocrine System)

Called APUD cells – Amine Precursor Uptake & Decarboxylation cells.
Present within the lining epithelium of the digestive and respiratory system.

Pituitary Gland(Hypophysis Cerebri)

Dual Origin of Pituitary

Partly from the developing brain (Neurohypophyseal bud )

Partly from the developing oral cavity (Hypophyseal ( Rathke ) pouch )

Formation of Pituitary Gland

Dual Origin of Pituitary Gland

Pituitary Gland

Adenohypophysis
Pars distalis
Pars tuberalis
Pars intermedia

Neurohypophysis

Pars nervosa
Stalk (Infundibulum)

Pituitary Gland

infundibular Stalk
Pars Nervosa
Pars Tuberalis
Pars Intermedia
Pars Distalis
Adenohypophysis
Neurohypophysis

Pituitary Gland

Pars distalis
Chromophils
Acidophils
Basophils
Chromophobes
Stain weakly
Few or no secretory granules
Stem & progenitor cells
Degranulated cells

Pars Distalis: Acidophil, Basophil & Chromophobe

Chromophils
Acidophils
Somatotrophs
Mammotrophs
Basophils
Gonadotrophs
Thyrotrophs
Corticotrophs

Acidophil, Basophil & Chromophobe

Somatotropic Cells

Ultrastructure
Immunohistochemistry

Control of the Pituitary

Hypothalamic-Hypophyseal Tract
Hypothalamic-Hypophyseal Portal System
Negative Feedback Loops

Hypothalamic-Hypophyseal Tract

Hypothalamic-Hypophyseal Portal System

Hypothalamic Control of pituitary function

Hypothalamic-Hypophyseal Portal System
Hypothalamo-Hypophyseal Tract

Negative Feedback Loops Affecting Anterior Pituitary Secretion

Pars Intermedia

Pars Nervosa
Pars Distalis
Cyst
Basophilic cells

Hormones of Pituitary

Adenohypophysis
• Growth hormone
• Prolactin
• FSH
• LH
• ACTH
• TSH
Neurohypophysis
• ADH
• Oxytocin
•

Gigantism & Dwarfism

Acromegaly

Pars Nervosa

• Neurosecretory Bodies
• Unmylinated axons
• Pituicytes

Neurosecretory Bodies

Pituicytes
Capillary

Hormones of Pituitary

Adrenal Gland

Adrenal Cortex
Origin from mesoderm
Features of steroid- secreting cells
Three concentric zones:
Zona Glomerulosa
Zona Fasciculata
Zona Reticularis

Adrenal Cortex

Zona Glomerulosa (15%): rounded or arched cords of columnar or pyramidal cells

Zona Fasciculata (65-80%): long cords of large polyhedral cells, one or two cells thick

Zona Reticularis (10%): smaller cells in a network of irregular cords

Adrenal Cortex Zones & Function

Zona Glomerulosa:
Aldosterone

Zona Fasciculata:

Cortisol
Zona Reticularis:
Androgen

Ultrastructure of Cortical Adrenalocytes

Lipid droplet
Mitochondria
Smooth Endoplasmic Reticulum

Cushing Syndrome

Adrenal Medulla

Origin from neural crest
Reddish brown in color
Cells called Chromaffin Cells
Profuse supply of sinusoidal capillaries

Adrenal Medulla Origin from Neural Crest

Chromaffin Cells

Modified neurons, lacking axons and dendrites
Specialized as secretory cells
Contain many electron-dense granules for storage and secretion of catecholamines
large, pale-staining polyhedral cells arranged in cords or clumps

Modified Neurons, Lacking Axons & Dendrites