What do the colors on the flag of Norway mean? Credit: Thinkstock Images Stockbyte Getty Images. The Union Jack is composed of the flags of three patron saints layered one over the other. The central red cross on a white field is the flag of St. George, the patron saint of England.
Synaptic vesicles contain thousands of neurotransmitter. The  neurotransmitters are packed into a small membrane bound synaptic  vesicles. There are thousands of neurotransm â¦ itter molecules.
The preoptic area of the hypothalamus contains thermo-sensitive neurons; these are important for TRH (thyrotropin releasing hormone) secretion. The hypothalamus receives many inputs from the brainstem; notably from the nucleus of the solitary tract, the locus coeruleus, and the ventrolateral medulla.