Composed mainly of hormone-producing chromaffin cells, the adrenal medulla is the principal site of the conversion of the amino acid tyrosine into the catecholamines epinephrine, norepinephrine, and dopamine.
42.
Adrenocorticotropic hormones bind to ACTH receptors on the cells within the adrenal medulla and adrenal cortex, causing a signal cascade within the adrenomedullary cell, ultimately releasing the neurotransmitter acetylcholine.
43.
Chromaffin cells of the adrenal medulla are analogous to post-ganglionic neurons; the adrenal medulla develops in tandem with the sympathetic nervous system and acts as a modified sympathetic ganglion.
44.
The adrenal medulla is considered a sympathetic ganglion and, like other sympathetic ganglia, is supplied by cholinergic preganglionic sympathetic fibers : acetylcholine is the neurotransmitter utilized at this synapse.
45.
Chromaffin cells of the adrenal medulla are analogous to post-ganglionic neurons; the adrenal medulla develops in tandem with the sympathetic nervous system and acts as a modified sympathetic ganglion.
46.
The mechanism lies in epinephrine being secreted by the adrenal medulla and activating glycogenolysis ( the break down of glycogen into glucose, or promoting gluconeogenesis ( glucose formation ).
47.
Therefore, this response that acts primarily on the cardiovascular system is mediated directly via impulses transmitted through the sympathetic nervous system and indirectly via catecholamines secreted from the adrenal medulla.
48.
The cells that stay in the sclerotome form the dorsal root ganglia, whereas those that continue more ventrally form the sympathetic ganglia, adrenal medulla, and the nerves surrounding the aorta.
49.
The adrenal medulla is derived from BMP-4 secreted in adrenal tissue is the main responsible for this, and that glucocorticoids only play a role in the subsequent development of the cells.
50.
It is secreted from the adrenal medulla along with epinephrine and trace amounts of dopamine, in addition to being present in the central nervous system that acts as a stimulatory neurotransmitter.
