At the Mammalian S and the Bird X, the glands suprarenals or more simply the suprarenals are two triangular endocrine Glande S located above the kidneys. They are mainly responsible for the management of the situations of Stress via the synthesis of Corticostéroïde S and Catécholamine S, inter alia the Cortisol and the Adrénaline.

General information

From an anatomical point of view, the suprarenal is located in position antérosupérieure compared to the kidney and is irrigated by the arteries suprarenals.

It is divided into two distinct structures:

• the medulla or adrenal medulla, of ectoblastic origin ;
• the cortex or corticosuprarenal, of mesoblastic origin .

These structures are both connected permanently to the Nervous system. As the name indicates it, the adrenal medulla is located inside the suprarenal, whereas the corticosuprarenal one recovers surface of it.

Embryology

The cortex surrénalien is resulting from mesodermic fabric (epithelium cœlomic). Whereas medullary the surrénalienne comes from cells of the peak neurale. The two parts meet after 7 weeks. The medullary one is invaginated gradually in the cortex. The fasciculée zone is formed after 20 weeks. The glomérulée zone is formed with the birth. The réticulée zone appears really only in the adult.

Adrenal medulla

The adrenal medulla is the body independent source of Hormone S of the group of the Catécholamine S (Adrénaline and Noradrénaline). The cells have usually cores bulky, pale, and a cytoplasm finely granulous; they are laid out in clusters, cords or columns, surrounded by a capillary rich person network. Part interns gland suprarenal which secret adrenalin. One of the roles of adrenalin is to involve a Tachycardie.

Corticosuprarenal

In contrast with the adrenal medulla, certain cells of corticosuprarenal belong to the Axe hypothalamo-hypophyso-surrénalien, and are a source of synthesis of the Cortisol. Other cortical cells produce Androgène S the such Testostérone, whereas some control the concentrations of Eau and electrolyte S by secreting Aldostérone.

The cells of corticosuprarenal contain a endoplasmic Réticulum smooth developed, many Mitochondrie S, lipidic Vacuole S and sometimes of the lipofuchsine, a marker of degeneration.

Outside towards the interior one distinguishes:

Shingles glomerulosa (glomérulée Zone)

The glomérulée zone synthesizes mainly Minéralocorticoïde S, namely the Aldostérone. It accounts for 15% of the corticosuprarenal one.

These cords are organized in networks rounded, in clusters.

Its structural organization is however quite specific of the animal specie, and the specialists can easily know if it is about a glomérulée zone of man, cat or rabbit.

Shingles fasciculata (fasciculée Zone)

The fasciculée zone synthesizes glucocorticoïdes, namely the Cortisol. It accounts for 65% of the corticosuprarenal one.

These cords are organized in parallel networks, radiate, of one to two layers of cells, and separated by capillaries.

Shingles reticularis (réticulée Zone)

The réticulée zone synthesizes Androgène S, DHEA and androstenedione. It accounts for 10% of the corticosuprarenal one.

These cords are organized in braided networks (connected).

Pathology

• congenital Disease of Addison

• Syndrome of Cushing
• Hyperplasie of the suprarenal
• Syndrome of Idiot
• Phéochromocytome

Blood irrigation

By the arteries capsulaires which are organized in a network under-capsulaire, cortical then medullary. There are of them three, the higher comes from the diaphragmatic arteries, the average of the aorta, and lower of the renal pedicle (the renal artery) since the kidney is right in lower part.

See too

• Reaction of the three F

• Stress

References

Simple: Adrenal nipple

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