ENDOCRINE SYSTEM I

Hypophysis (Pituitary)

Supra renal (adrenal)

HYPOTHALAMUS

NERVOUS

SYSTEM

NEURAL

IMPULSE

ENDOCRINE

SYSTEM

HORMONES

ENDOCRINE GLANDS

•DISCRETE GLANDS •HYPOPHYSIS

•THYROID

•PARATHYROID

•ADRENAL

•PINEAL

•Glands associated with exocrine •Pancreas

•Kidney

•Gonads

•Placenta

•Diffuse scattered cells •Entero chromoffin system • APUD

HORMONES

•Steroid •Testosterone (Testis, Suprarenal),

•Estrogen(Ovary, Suprarenal)

•Peptide • Insulin (islets of Langerhans),

•Parathormone (Parathyroid)

•Prolactin (Pituitary)

•Amino acid analogues and derivatives •Nor epinephrine, epinephrine

PITUITARY GLAND

PITUITARY GLAND

PITUITARY GLAND

•Anterior pituitary • Ectoderm

• Roof of mouth

• Rathke’s pouch

• Detaches from roof

•Posterior pituitary • Neuro ectoderm

• Floor of diencephalons

• Connected by infundibulum

BLOOD SUPPLY •Portal circulation

•Superior and inferior hypophyseal arteries

•Primary plexus around median eminence and infundibulum

•Hypophyseal portal vein enters adenohypophysis as secondary plexus

HYPOPHYSIS CEREBRI

•Pituitary gland • Adenohypophysis

• Neurohypophysis

•Adenohypophysis • Pars tuberalis

• Pars distalis

• Pars intermedialis

•Neurohypophysis • Infundibulum

• Pars nervosa

•Median eminence

ADENOHYPOPHYSIS

•Cells arranged as branching cords, clusters

•Sinusoids

•Secretes trophic hormones

SINUSOIDS

ADENOHYPOPHYSIS •Cell type

•Chromophobes • Inactive cells

• Do not take stain

• Cytoplasm scanty

• Appears in group

• Nucleus of cell appear closer

• Precursor of chromophils

CHROMOPHOBES

ADENOHYPOPHYSIS

•Chromophils

•Active cells

•Alpha cells

•Acidophils

•Beta cells

•Basophils

•Acidophils

• Somatotrophs • Ovoid ells

• Cluster arrangements around sinusoids

• Growth hormone

• Orange G

•Mammotrophs • Scattered with somatotrophs

• Increase during pregnancy and lactation

• Eyrthrosin, azocarmine

STH

MTH

•BASOPHILS

•Corticotrophs • Cells appear irregular

• ACTH

•Thyrotrophs • Angulated cells

• Aldehyde fuchin stain

• TSH

•Gonadotrophs • Round/ovoid cells

• Close to sinusoid

• FSH, LH, ICSH

TSH

GH

PARS TUBERALIS

•High vascularity

•Alpha and beta cells

•Cords and clusters of undifferentiated cells

•Few gonadotrophs cells

PARS INTERMEDIALIS

•Not well developed in human

• Irregular row of follicles with colloidal materials

•Few acidophil and basophil cells are seen

•MSH in lower vertebrates

•Few cells reported to secrete endorphins

PARS NERVOSA

•Unmyelinated nerve fibers

•Hypothalamo-hypophyseal tract

• Pituicytes- stellate cells

• Secreted materials stored in vesicles-Herring bodies

• Vasopressin

•Oxytocin

SUPRA RENAL GLAND

SUPRA RENAL GLAND

•Surrounded by capsule

•Septae carrying blood vessels

•Cortex + medulla

•Cortex-3 zones • Zona glomerulosa

• Zona fasciculata

• Zona reticularis

SUPRA RENAL –CORTEX

•Zona glomerulosa • Irregular cluster around

capillaries

• Polyhedral cells

• Cytoplasm uniformly stained

• Secretes minerlocorticoids (aldosterone)

• Poorly developed in human

SUPRA RENAL -CORTEX

•Zona fasciculata

•Cells arranged in cords

•Straight capillaries between

•Vacuolated cytoplasm

•Rich in cholestrol and vitamin C

•Secretes glucocorticoids

SUPRA RENAL - CORTEX

•Zona reticularis

•Cells arranged in cords

•Cell depicts dark and light nuclei

•Runs in different direction

•Anastomose with one another

•Secretes sex hormones

ADRENAL MEDULLA

•Cells arranged as clumps and cords

• Large ovoid cells-pheochromocytes

•Cytoplasm stains with chrome salts

•Nerve cells may be found

• Large vein

DISPOSITION OF BLOOD VESSELS

•Capsular artery-

•>capillary network in ZG-

•>straight capillary network in ZF

•>meshwork of sinusoids in ZR

•Medulla – medullary vein

DISPOSITION OF BLOOD VESSELS

•Capsular arteries

•>medullary arteriole

•>medullary capillaries

•>medullary vein

SUPRA RENAL GLAND

ZG

ZF

MEDULLA

ZR

CAP

SUPRA RENAL GLAND

CORTEX

MEDULLA