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:
Las células madre son células que se reproducen constantemente y tienen la capacidad de transformarse en cualquier otro tipo de célula del cuerpo de un organismo. Una célula a partir de la cual pueden crecer todos los tejidos del cuerpo, o una gran parte de ellos, es obviamente una célula extremadamente útil.
Si las células madre se guían en la formación de tejidos sanos y funcionales, entonces, potencialmente, la terapia celular podría aplicarse para muchas enfermedades. De hecho, si las células provienen del propio paciente, en teoría no habrá riesgo de su rechazo (como lamentablemente ocurre con los trasplantes).
Las células madre tienen la capacidad de reproducirse por sí mismas a través del proceso de mitosis celular, para crear copias idénticas (clones) de sí mismas..
Alfred Marshal was one of the most influential economists of his time and the author of the Principles of Economics book which was the principal economic textbook in England for long years. During his economic theory development, he borrowed a concept from the marginalists which is the theory of demand and the collective result of buyers who yearns services and products or the concept of scarcity.
A. Polysaccharide, this is because polysaccharides have cellulose which make the grass stand up.
