What are the suprarenal glands and what do they do?

The suprarenal (adrenal) glands are paired endocrine organs located at the upper poles of the kidneys. They consist of two main parts: the cortex, which produces steroid hormones for functions like electrolyte balance and glucose regulation, and the medulla, which secretes adrenaline and noradrenaline (catecholamines) for stress responses.

Where are the suprarenal glands located in the body?

They are situated anterosuperior to each kidney in the epigastric region. The right gland is triangular and lies between the diaphragm, IVC, right liver lobe, and kidney, while the left gland is crescentic and bordered by the diaphragm, stomach, pancreas, splenic artery, and kidney.

What is the structure of the adrenal cortex?

The adrenal cortex has three distinct layers: Zona glomerulosa (outer layer of small, polyhedral cells), Zona fasciculata (middle layer with columns of large cells), and Zona reticularis (inner meshwork of interlacing cells). These layers produce steroid hormones essential for metabolism and stress adaptation.

How do the right and left suprarenal glands differ in venous drainage?

The right suprarenal vein drains directly into the inferior vena cava (IVC), while the left suprarenal vein drains into the left renal vein. This anatomical difference is important in surgical procedures like adrenalectomy.

What are some common clinical conditions associated with the suprarenal glands?

Key conditions include Addison’s disease (cortical insufficiency causing weakness and hyperpigmentation), Cushing syndrome (cortical hypersecretion leading to obesity and hypertension), and Pheochromocytoma (medullary tumor causing episodic hypertension and tachycardia).

What is the nerve supply to the suprarenal glands?

Innervation is primarily from preganglionic sympathetic fibers via splanchnic nerves, which terminate on chromaffin cells in the medulla. The cortical function is regulated by ACTH from the anterior pituitary.

How do the suprarenal glands develop embryologically?

The cortex is derived from mesoderm (peritoneal lining), while the medulla originates from neural crest cells. Accessory glands, which may contain only cortical tissue, can sometimes develop in areas like the spermatic cord or broad ligament.

Adrenal (Suprarenal) Glands – Cortex vs Medulla

❓ Frequently Asked Questions