In 1913 Bohr proposed his quantized shell model of the atom to explain how electrons can have stable orbits around the nucleus.n 1913 Bohr proposed his quantized shell model of the atom to explain how electrons can have stable orbits around the nucleus.
Norepinephrine, also called noradrenaline, is an organic chemical in the catecholamine family that functions in the human brain and body as a hormone and neurotransmitter.n the most basic terms, the function of norepinephrine is to mobilize the brain and body for action. Norepinephrine release is lowest during sleep, rises during wakefulness, and reaches much higher levels during situations of stress or danger, in what has been called the fight-or-flight response.
In the brain, norepinephrine comes from several nuclei that are small in size but project to most other parts of the brain and exert powerful effects on their targets. The most important source of norepinephrine in the brain is the locus coeruleus, located in the pons.n the sympathetic nervous system norepinephrine is used as a neurotransmitter by sympathetic ganglia located near the spinal cord or in the abdomen, and is also released directly into the bloodstream by the adrenal glands.