Endocrine Glands II Adrenal glands Prof Menna AbdelDayem

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Endocrine Glands II Adrenal glands Prof Menna Abdel-Dayem

Endocrine Glands II Adrenal glands Prof Menna Abdel-Dayem

Adrenal Glands

Adrenal Glands

Suprarenal (Adrenal) Glands ● Two endocrine glands in contact with upper border of both

Suprarenal (Adrenal) Glands ● Two endocrine glands in contact with upper border of both kidneys. ● Derived from 2 embryonic sources: the mesoderm gives rise to adrenal cortex & neuroectoderm gives rise to adrenal medulla.

Suprarenal (Adrenal) Glands

Suprarenal (Adrenal) Glands

Suprarenal (Adrenal) Glands Stroma: Capsule, trabeculae and reticular framework Parenchyma: Cortex Medulla

Suprarenal (Adrenal) Glands Stroma: Capsule, trabeculae and reticular framework Parenchyma: Cortex Medulla

Suprarenal (Adrenal) Glands Stroma: Capsule: thick, covered with adipose C. T. Trabeculae: thin, descend

Suprarenal (Adrenal) Glands Stroma: Capsule: thick, covered with adipose C. T. Trabeculae: thin, descend from the capsule to divide the cortex into compartments. Reticular framework

Adrenal Cortex

Adrenal Cortex

Zona Glomerulosa

Zona Glomerulosa

Zona fasciculata

Zona fasciculata

Zona Reticularis

Zona Reticularis

Suprarenal (Adrenal) Cortex 1 -Zona Glomerulosa 2 -Zona Fasciculata 3 -Zona Reticularis The narrowest

Suprarenal (Adrenal) Cortex 1 -Zona Glomerulosa 2 -Zona Fasciculata 3 -Zona Reticularis The narrowest zone. -The widest zone. just under the capsule -Polyhedral cells arranged in narrow & -Polyhedral cells arranged in branching & -Columnar cells straight cords arranged in arched groups (glomeruli) (fascicles)separated by surrounded by fenestrated capillaries -The deepest zone. anastomosing cords separated by blood sinusoids. L. M. -Columnar cells with Polyhedral cells with central rounded pale Polyhedral cells with central rounded nuclei basal rounded nuclei vesicular nuclei. & pale cytoplasm Some cells are binucleated with acidophilic vacuolated cytoplasm , so called Spongiocytes. L. M. & acidophilic cytoplasm

Suprarenal (Adrenal) Cortex 1 -Zona Glomerulosa 2 -Zona Fasciculata 3 -Zona Reticularis E. M.

Suprarenal (Adrenal) Cortex 1 -Zona Glomerulosa 2 -Zona Fasciculata 3 -Zona Reticularis E. M. Rich in mitochondria, G. A. , s. ER & few fat droplets G. A. , s-ER, many fat droplets, few fat droplets. Lipofuscin pigment cholesterol & vitamin C (androgens) is commonly seen Function: Secrete mineralocorticoids Secrete glucocorticoids (cortisol) that Secrete androgen & small amount of mainly Aldosterone which regulate H 2 O & regulate Electrolyte balance metabolism. (under control of inflammatory & immuno- suppressive angiotensin II) action. lipid, protein& Have an CHO anti- glucocorticoids

Adrenal Medulla

Adrenal Medulla

Adrenal Medulla 1. Chromaffin cells: – Modified sympathetic neurons that have lost their processes

Adrenal Medulla 1. Chromaffin cells: – Modified sympathetic neurons that have lost their processes and became secretory cells. – Polyhedral cells arranged in branching cords separated by blood sinusoids. – Have basophilic cytoplasm rich in fine granules that stain brown with chromium salts & central rounded pale nuclei.

Adrenal Medulla 1. Chromaffin cells: EM: • Cytoplasm shows mitochondria, well developed Golgi apparatus,

Adrenal Medulla 1. Chromaffin cells: EM: • Cytoplasm shows mitochondria, well developed Golgi apparatus, r. ER & membrane-bound secretory granules. • There are 2 types of cells at ultrastructural level: a) Adrenalin secreting cells: with less dense & homogeneous granules, i. e. the contents fill the granules. b) Noradrenalin secreting cells: with more dense granules and peripheral clear halo beneath the membrane. The secretory granules also contain opiate-like peptides = enkephalins.

Adrenal Medulla 2. Sympathetic nerve cells: Stellate nerve cells scattered between chromaffin cells to

Adrenal Medulla 2. Sympathetic nerve cells: Stellate nerve cells scattered between chromaffin cells to stimulate their secretory activity. Innervated by preganglionic sympathetic nerve fibers.

Functions of the Adrenal Medulla • Secrete adrenalin (epinephrine) & noradrenalin (norepinephrine) in response

Functions of the Adrenal Medulla • Secrete adrenalin (epinephrine) & noradrenalin (norepinephrine) in response to stress (fight, flight & fright). • During normal activity, the medulla continuously secretes small amounts of the 2 hormones.

Migrated sympathetic ganglion: 1 - Innervation ………. 2 - Embryologic origin ………… 3 -

Migrated sympathetic ganglion: 1 - Innervation ………. 2 - Embryologic origin ………… 3 - contain …………

Paraganglia Masses of chromaffin cells scattered in close association with the sympathetic ganglia. They

Paraganglia Masses of chromaffin cells scattered in close association with the sympathetic ganglia. They develop from neuroectoderm (like sympathetic ganglia). Give +ve chromaffin reaction. Function: secrete adrenalin & noradrenalin and enkephalins

Blood Supply Three suprarenal arteries (superior, middle & inferior) pierce the capsule → 3

Blood Supply Three suprarenal arteries (superior, middle & inferior) pierce the capsule → 3 groups of arterioles (capsular, cortical & medullary). The cortical capillaries drain into veins of medulla which join to form suprarenal vein that leave the gland

Cortex and Medulla Cortex Medulla Mesodermal in origin Ectodermal Formed of 3 zones (glomerulosa,

Cortex and Medulla Cortex Medulla Mesodermal in origin Ectodermal Formed of 3 zones (glomerulosa, fasciculate & reticularis) Two types of cells (chromaffin& nerve cells) Essential to life (corticosteroids) Less essential Secretes mineralocorticoids, glucocorticoids & Secretes adrenalin, noradrenalin & enkephalins sex hormones Give –ve chromaffin reaction +ve reaction Supplied with arterial blood Supplied with arterial & venous blood