Answer:
Population dynamics can be described as the size of a particular population and the environmental and biological factors which influence it.
For human populations, a population which is greater than the resources can be controlled by decreasing the number of births in that population. It can be controlled by people migrating from the place due to less resources available.
For animals, the population can be controlled by increasing the amount of predators for the particular population so that they decline in number. Or shifting of the organisms can be done to places where there are enough resources available.
They are thus known as the "supporting cells" of the nervous system. The four main functions of glial cells are: to surround neurons and hold them in place, to supply nutrients and oxygen to neurons, to insulate one neuron from another, and to destroy and remove the carcasses of dead neurons (clean up).
The answer is Catecholamine. It is any of a class of aromatic amines that includes a number of neurotransmitters such as epinephrine and dopamine. The adrenergic receptors are a class of G protein-coupled receptors that are targets of the catecholamines, especially norepinephrine (noradrenaline) and epinephrine (adrenaline). These three - catecholamine, peptide hormones and eicosanoids acts as extracellular membrane receptors which means that these receptors are embedded in the membranes of cells. They act in cell signaling by receiving (binding to) extracellular molecules.
