In the lumbar region, neural crest cells differentiate into the cells of the adrenal medulla, the inner part of the adrenal gland that sits atop the kidneys.
And from a very tiny, underused part of my brain — probably located at the base of my medulla oblongata where my subconscious dwells — comes the thought: he's here to see you.
The medulla is made up of 10 to 18 renal pyramids with the base of the pyramids facing the renal cortex and the tips of the pyramids, called renal papilla—or nipples, pointing towards the center of the kidney.
Together, the sympathetic chain and adrenal medulla form the sympathetic nervous system, connecting the brain and central nervous system to various organs including the heart and blood vessels.
Each nephron consists of a round renal corpuscle that resides up in the cortex, followed by a long and winding renal tubule that loops around between the cortex and the medulla.
The sympathetic neurons releases norepinephrine, also called noradrenaline, and the cells of the adrenal medulla release norepinephrine and epinephrine, also called adrenaline.
Alright, as a quick recap, neuroblastoma is a condition where neural crest cells of the developing sympathetic nervous system and adrenal medulla do not differentiate normally.
For the next few hours, as my stomach grows distended from the food, it activates stretch receptors that again stimulate my medulla and get my vagus nerves to tell my stomach to turn up the juice.
And the form of this loop is key to its function, because its primary task is to drive the re-absorption of water, by creating a salt concentration gradient in the tissue of the medulla.
They use it to ramp up the concentration gradient earlier in the process, making the medulla even saltier for the filtrate that's back there going through the ascending limb.