Anatomy and Physiology of the Adrenal Glands

Adrenal Glands

Also known as suprarenal glands, endocrine organs.

ACTH

Hormone from anterior pituitary controlling adrenal glands.

Gerota's fascia

Connective tissue enclosing the adrenal glands.

Adrenal Cortex

Outer layer of adrenal glands, secretes steroids.

Adrenal Medulla

Inner layer of adrenal glands, secretes catecholamines.

Zona Glomerulosa

Layer producing mineralocorticoids like aldosterone.

Zona Fasciculata

Layer producing glucocorticoids like cortisol.

Zona Reticularis

Layer producing sex hormones and androgens.

Epinephrine

Increases heart rate and blood pressure during stress.

Norepinephrine

Accelerates heart rate and contracts blood vessels.

Fetal Adrenal Size

10-20 times larger than adult adrenal glands.

Infant Adrenal Size

1/3 of renal length compared to adults.

Adult Adrenal Size

1/13 of renal length, smaller than infants.

Right Adrenal Gland

Triangular or pyramid-shaped, located near IVC.

Left Adrenal Gland

Semilunar or crescent-shaped, medial to left kidney.

Vascular Supply

Three arteries supply blood to each adrenal gland.

Sup. Suprarenal Artery

Branches off inferior phrenic artery to adrenal glands.

Middle Suprarenal Artery

Branches off the aorta to supply adrenal glands.

Inf. Suprarenal Artery

Branches off renal artery supplying adrenal glands.

Suprarenal Vein

Single vein draining each adrenal gland into IVC.

Catecholamines

Hormones secreted by adrenal medulla for stress response. Includes epinephrine, norepinephrine, and dopamine.

Left suprarenal vein

Drains into the left renal vein.

Aldosterone

Regulates blood pressure and electrolyte levels and blood pressure via sodium and water control.

Cortisol

Aids in glucose metabolism and inflammatory response.

Adrenocorticotropic hormone (ACTH)

Controls adrenal cortex hormone production.

Total metanephrines

Used to assess catecholamine production.

Vanillymandelic acid

Metabolite of catecholamines in urine.

Conn syndrome

Overproduction of aldosterone causing hypertension.

Cushing syndrome

Overproduction of cortisol leading to various symptoms.

Addison's disease

Adrenal insufficiency resulting in low hormone production.

Adrenal adenoma

Benign tumor of the adrenal gland.

Adrenal adenocarcinoma

Malignant tumor of the adrenal cortex.

Bilateral adrenal hyperplasia

Enlargement of both adrenal glands.

Hyperpituitarism

Excessive hormone production by the pituitary gland.

Adrenal hyperplasia

Increased number of adrenal cells.

Androgens

Hormones like testosterone and estrogen from adrenal glands.

DHEA-S

Dehydroepiandrosterone sulfate, an androgen precursor.

Sonographic evaluation

Ultrasound assessment of adrenal glands.

Patient positioning

Oblique or decubitus position for adrenal imaging.

Adrenal hemorrhage

Most common adrenal mass in newborns.

Adrenal cyst

Rare benign lesion, often asymptomatic.

Neuroblastoma

Malignant tumor often originating in adrenal glands.

Adrenal myolipoma

Benign tumor composed of fat and muscle.

Unilocular cyst

Simple cyst in the adrenal gland, typically benign.

Complex cyst

Cyst with multiple components, may indicate pathology.

Calcified cyst

Cyst containing calcium deposits, often benign.

Adrenal Adenoma

Most common benign adrenal mass, <3 cm.

Hyperfunctioning adenoma

Secretes hormones, associated with Cushing's or Conn's.

Asymptomatic presentation

No symptoms, often found incidentally during imaging.

Cushing's syndrome

Hormonal disorder from excess cortisol production.

Conn's disease

Hyperaldosteronism causing hypertension and electrolyte imbalance.

Sonographic appearance

Visual characteristics of masses on ultrasound imaging.

Pheochromocytoma

Rare, vascular tumor secreting excess catecholamines, may be malignant.

Chromaffin tissue

Tissue in adrenal medulla producing epinephrine and norepinephrine.

Uncontrolled hypertension

High blood pressure not managed by treatment.

Adrenal Myolipoma

Benign mass with fat and bony elements, nonfunctioning.

Propagation speed artifact

Ultrasound artifact due to differing tissue speeds.

Adrenal Neuroblastoma

Most common malignant tumor in children, arises in medulla.

Pediatric sarcoma

Cancerous tumor occurring in children, often aggressive.

Elevated catecholamines

Increased hormone levels indicating adrenal gland dysfunction.

Adrenal Cortical Carcinoma

Rare malignant tumor, aggressive, poor prognosis.

Androgenital syndrome

Hormonal disorder causing abnormal sexual development. Excess androgens causing virilism in females.

Metastasis

Spread of cancer from primary site to adrenal glands.

Heterogeneous appearance

Varied texture and composition seen in tumors.

Internal vascularity

Blood supply within a tumor, indicating potential malignancy.