endocrine system i modified ug - copy
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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
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