Brain

The brain is a pinkish-grey, wrinkled organ that fills the skull — looking, for all the world, like a huge walnut. It is hard to believe, from its appearance, that this ugly lump of jelly contains the mechanisms of thought, perception, will, and consciousness, that it is the seat of our personality. Its 100,000 million nerve cells, each with an average of 100,00 connections from other neurons, makes the human brain the most complicated and least understood object in the known universe. The vertebrate brain is the large anterior portion of the central nervous system . The "cranial vault" of the skull encases the brain in most vertebrates. In invertebrates, the enlarged and specialized anterior ganglion of the central nervous system is often referred to as a brain, although not all scientists regard it as a true brain.

Pheochromocytoma

A pheochromocytoma (fe-o-kro-mo-si-TOE-muh) is a rare, usually noncancerous (benign) tumor that develops in the core of an adrenal gland. You have two adrenal glands, one just above each of your kidneys. Your adrenal glands produce hormones that give instructions to virtually every organ and tissue in your body.
If you have a pheochromocytoma, your adrenal glands can produce too much of certain hormones, raising your blood pressure and heart rate. A pheochromocytoma may be life-threatening if unrecognized or untreated. A pheochromocytoma can develop at any age, but most commonly occurs in middle age. Usually, treatment for pheochromocytoma can return blood pressure to normal.