The adrenal gland is very vascular, receiving an estimated 6 to 7 ml/g per minute, or about 25ml/minute in the resting state. Why does it have such a large blood supply? The body’s second to second need to respond to crisis situations requires enough blood to pass by the adrenals to circulate important and necessary hormones.
The blood supply of the adrenal gland is derived from three adrenal arteries: the superior artery is a branch of the inferior phrenic artery; the middle artery arises directly from the aorta; and the inferior artery arises from the renal artery.
The primary blood supply of the right adrenal comes from the superior and inferior adrenal arteries, whereas the left adrenal is supplied primarily by the middle and inferior adrenal arteries. The three arteries branch, and each gland may have up to 50 small arterial branches enter the perimeter, supplying a gland that obviously commands a tremendous blood supply.
This coronal T1-weighted image has been overlayed with the arterial anatomy of the adrenal. Each gland receives arterial blood from three arteries – the superior, middle and inferior adrenal arteries. Courtesy of: Ashley Davidoff, M.D.
.
There are three adrenal arteries – the superior that arises from the inferior phrenic artery, the middle that arises directly off the aorta and the inferior that arises from the renal artery usually as a branch of the capsular artery. This schematic only shows 3 branches per vessel, but in reality there is extensive branching before each artery actually enters the gland. Courtesy of: Ashley Davidoff, M.D.This image shows a schematic of the histologic distribution of the adrenal arterial supply and venous drainage. The dominant area of arterial supply is the cortex, and the dominant area of venous drainage is the medulla.Courtesy of: Ashley Davidoff, M.D.
Anatomy and Physiology of the Adrenal Glands: Arterial Supply – Intra- Adrenal Anatomy
Up to 50 to 60 small feeder vessels penetrate the anterior and posterior surfaces of the glands and form a plexus beneath the capsule. Cortical arteries supply the cortex from the subcapsular plexus, which drains centripetally toward the medulla. Medullary arteries pass through the cortex and supply the medulla directly. In the zona reticularis, the capillaries coalesce to form progressively larger venous sinuses that drain centrally.
Medullary capillaries form venous channels, which eventually forms a single adrenal vein that usually drains into the vena cava on the right and into the renal vein on the left.
This image shows a schematic of the histologic distribution of the adrenal arterial supply and venous drainage. The dominant area of arterial supply is the cortex, and the dominant area of venous drainage is the medulla.Courtesy of: Ashley Davidoff, M.D.
Anatomy and Physiology of the Adrenal Glands: Arterial Supply – Imaging
This image reflects the right renal artery with the capsular branch arising from within 2 cm. from the aortic origin. The inferior adrenal artery is overlayed in red and can be seen terminating in a tuft of vessels at the adrenal gland.Courtesy of: Ashley Davidoff, M.D.In this instance the middle and superior adrenal arteries can be seen supplying the right adrenal gland.(yellow overlay)Courtesy of: Ashley Davidoff, M.D.
Anatomy and Physiology of
This image depicts the relationship of the middle and superior adrenal arteries with the adrenal gland and the superior pole of the right kidney. Courtesy of: Ashley Davidoff, M.D.
Adrenal Glands: Arterial Supply – Abnormal
In this injection of the middle adrenal artery, a mass is apparent in the right adrenal gland. The branches of the artery are distorted and, rather than a triangular shape as seen on previous image, we see a rounded mass. There is evidence of early venous filling (blue overlay) reflecting an arteriovenous shunt, characteristic of a hypervascular tumor.Courtesy of: Ashley Davidoff, M.D.
