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Beginning in the sympathetic nervous system, an external stimulus affects the adrenal medulla and causes a release of catecholamines. The sympathoadrenal system is a physiological connection between the sympathetic nervous system and the adrenal medulla and is crucial in an organism's physiological response to outside stimuli. [1]
The adrenal medulla is the principal site of the conversion of the amino acid tyrosine into the catecholamines; epinephrine, norepinephrine, and dopamine. Because the ANS, specifically the sympathetic division, exerts direct control over the chromaffin cells , the hormone release can occur rather quickly. [ 2 ]
An adrenal tumor or adrenal mass [2] is any benign or malignant neoplasms of the adrenal gland, several of which are notable for their tendency to overproduce endocrine hormones. Adrenal cancer is the presence of malignant adrenal tumors, and includes neuroblastoma , adrenocortical carcinoma and some adrenal pheochromocytomas .
The adrenal medulla is at the centre of each adrenal gland, and is surrounded by the adrenal cortex. The chromaffin cells of the medulla are the body's main source of the catecholamines, such as adrenaline and noradrenaline, released by the medulla. Approximately 20% noradrenaline (norepinephrine) and 80% adrenaline (epinephrine) are secreted here.
An example of a neuroendocrine cell is a cell of the adrenal medulla (innermost part of the adrenal gland), which releases adrenaline to the blood. The adrenal medullary cells are controlled by the sympathetic division of the autonomic nervous system. These cells are modified postganglionic neurons. Autonomic nerve fibers lead directly to them ...
Pituitary gland tumors are very common in the canine. A productive form arising from the anterior pituitary is the primary cause of Cushing's disease of dogs. This tumor causes excessive production of cortisol from the adrenal cortex which leads to the classic signs of alopecia (hair loss), polyuria (excessive urination), polydipsia (excessive water drinking), and a pot-bellied appearance of ...
When an adrenal nodule (potential tumor) is discovered on computed tomography or magnetic resonance imaging, there is a 5–10% chance the lesion is a pheochromocytoma. [175] The incidence of adrenal tumors is found in the infographic above, with pheochromocytoma noted in yellow in the top right corner.
They are concentrated near the adrenal glands and essentially function the same way as the adrenal medulla. They are sometimes found in connection with the ganglia of other sympathetic plexuses . None have been found with the sympathetic ganglia associated with the branches of the trigeminal nerve .