Notas
General
* Also known as adrenal glands
* Secretes steroid hormones and catecholamine
* Have a flattened triangular shape and are embedded in the perirenalfat at the superior poles of the kidneys
* Covered with thick connective tissue capsule from which trabeculae extend into the parenchyma, carrying blood vessels and nerves
* Secretoryparenchymal tissue is organized into cortical and medullary regions
* The Cortex is the steroid secreting portion, lies beneath the capsule and is nearly 90% of the gland by weight
* The medulla isthe catecholamine secreting portion, it is deep in the cortex and forms the center of the gland
* The cortical cells are from the mesodermal mesenchyme, medulla from the neural crest
*Parenchymal cells of adrenal cortex are controlled by the anterior lobe of the pituitary gland and function in regulating metabolism and maintain normal electrolyte balance
Blood Supply
* Adrenalglands are supplied with blood by the superior, middle and inferior suprarenal arteries
* In the capsule the arteries branch to give rise to 3 principal patterns of blood distribution:
*Capsular Capillaries: supply the capsule
* Fenestrated Cortical Sinusoidal Capillaries: supply the cortex and then drain into the fenestrated medullary capillary sinusoids
* Medullary Arteries:traverse the cortex traveling within the trabeculae and bring arterial blood to the medullary capillary sinusoids
* Venules that arise from the cortical and medullary sinusoids drain into the smalladrenomedullary collecting veins that join to form the large central adreomedullary vein which drains into the inferior vena cava
* Lymphatic vessels are present in the capsule and the connectivetissue around the larger blood vessels in the gland
Cells of the Adrenal Medulla
* Chromaffin cells located in the adrenal medulla are innervated by preganglionic sympathetic neurons, the...
Regístrate para leer el documento completo.