Answer:
The correct option is: <em>a deficiency of dopamine in the substantia nigra.</em>
Explanation:
The substantia nigra is the principal site involved in the physiopathology of Parkinson´s disease.
Cells from this area degenerate and die progressively causing important degeneration in the central nervous system. The cells that die -with no known reason- are those that produce dopamine and proportionate dopaminergic innervation to the encephalon. In fact, almost all the symptoms exhibited by patients with the disease can be explained by the lack of dopamine in the substantia nigra.
This area uses the neurotransmitter to communicate neurons from the base ganglia. Ganglia are responsible of modulating and modifying movements.
The nigrostriatal system participates in planning and automatic execution of learned movements. When the ganglia activity decreases, so it does the amount and velocity of movements, something typical of the disease.
This isn't always the case and there is no reason it should be .Whether or not a trait is common has to do with how many copies of that gene version (or allele) are in the population. It has little or nothing to do with whether the trait is dominant or recessive. Let's take eye color as an example.
I just did this BTW. The correct answer is A.) Nuclear fusion is the correct answer. Nuclear fission is what we use today in nuclear power plants, a great deal of radioactive waste, the other are by products of this process. Nuclear fusion releases a great deal of energy with a little radioactivity, but the problem is ignition temperatures; but maybe someday.
Answer:
The Cardiovascular System
Explanation:
The respiratory system draws air into the lungs. Oxygen diffuses through the walls of the alveoli and across the walls of the capillaries where it enteres the bloodstream. The oxygen molecules are picked up by red blood cells, which are pumped through the blood vessels by the action of the heart. As the red blood cells carrying oxygen pass through capillaries near the cells, oxygen diffuses into the cells.
