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.
Answer:
Moisture - There must be sufficient water vapor in the air for a cloud to form. Cooling air - The air temperature must decrease enough for water vapor to condense.
Explanation:
Answer:
The correct answer is -
Euglena - single-cell organism
Onion bulb - organ
Blood - tissue (connective tissue)
Explanation:
The level of organization of an organ, or organism could be cellular level, tissue level, the organ level, organ system, or a complete organism. These levels are formed by assembling the lower level of the organization.
Euglena is a single-cell eukaryotic organism found in freshwater. These organisms have a very simple level of an organism which is cellular level. The onion bulb is the organ of the onion plant composed of shortened, compressed, underground stems (tissue) that are an organ-level organization.
The blood is considered as connective tissue due to the blood cells present in the matrix called plasm thus, blood is connective tissue.
Lack of exercise
High blood pressure
Diabetes
Obesity and high cholesterol