Anatomy of Suprarenal Glands Yuniarti Anatomy Department Faculty of Medicine UNISBA Location of Suprarenal Glands • Located between the superomedial aspects of the kidneys and the diaphragm •The pyramidal right gland is more apical (situated over the superior pole) relative to the right kidney, lies anterolateral to the right of the diaphragm, and makes contact with the IVC anteromedially and the liver anterolaterally • The crescent-shaped left gland is medial to the superior half of the left kidney and is related to the spleen, stomach, pancreas and the left of the diaphragm • Suprarenal glands surrounded by connective tissue containing considerable perinephric fat • Suprarenal glands are enclosed by renal fascia by which they are attached to the crura of the diaphragm • Each gland has a hilum, where the veins and lymphatic vessels exit the gland; whereas arteries and nerve enter the glands at multiple sites • They are separated from the kidneys by a thin septum (part of the renal fascia) •The medial borders of the suprarenal glands are 4-5 cm apart. In this area, from right to left, are the IVC, right of the diaphragm, celiac ganglion, celiac trunk, SMA and the left of the diaphragm. •Each suprarenal gland has two parts : ~ Suprarenal cortex ~ Suprarenal medulla SUPRARENAL CORTEX • Derives from mesoderm Three zones in suprarenal cortex Outer zone / zona glomerulosa middle zone / zona fasciculata Inner zone / Zona reticularis Mineralocorticoid Glucocorticoid Androgen hormone hormone hormone Mineralocorticoid • Aldosterone is the major mineralocorticoid. • It regulates homeostasis of two mineral ions, namely sodium ions (Na) and potassium ions (K), and helps adjust blood pressure and blood volume. • Aldosterone also promotes excretion of H+ in the urine; this removal of acids from the body can help prevent acidosis •include cortisol (hydrocortisone), corticosterone, and cortisone Glucocorticoid •Function : Protein breakdown, glucose formation, lipolysis, resistance to stress, anti-inflammatory effects, depression of immune responses •The major androgen secreted by the adrenal gland is dehydroepiandrosterone (DHEA) Androgen •Function : promote libido (sex drive) and are converted into estrogens (feminizing sex steroids) by other body tissues; after menopause, when ovarian secretion of estrogens ceases all female estrogens come from conversion of adrenal androgens; stimulate growth of axillary and pubic hair in boys and girls and contribute to the prepubertal growth spurt. SUPRARENAL MEDULLA • Derive from neural crest cells associated with the sympathetic nervous system • The cromaffin cells secrete catecholamines / epinephrine and norepinephrine (NE), also called adrenaline and noradrenaline, respectively. • Unlike the hormones of the adrenal cortex, the hormones of the adrenal medulla are not essential for life sincethey only intensify sympathetic responses in other parts of the body. Action of catecholamine : 1. Increased heart rate 2. Increased force of cardiac muscle contraction 3. Elevated blood pressure 4. Increased breathing rate 5. Decreased activity in the digestive system Vascularisation of suprarenal glands Suprarenal glands arteries : ~ Superior suprarenal arteries ~ Middle suprarenal arteries ~ Inferior suprarenal arteries Venous drainage : ~ Right suprarenal vein drains into the IVC ~ Left suprarenal vein drains into the left renal vein Lymphatic Suprarenal Glands The lymph passes to the right & left lumbar lymph nodes Nerves of the suprarenal glands • Celiac plexus •Abdominopelvic (greater, lesser and least) splanchnic nerve •Myelinated presynaptic sympathetic fibers mainly derived from lateral horn of gray matter of the spinal cord segments T10-L1 -- transverse both the paravertebral and the prevertebral ganglia, without synapse, to be distributed to the chromaffin cells in the suprarenal medulla.