Answer:
C: Afectan principalmente a nuestro sistema nervioso central
Explanation:
Al ingerir sustancias adictivas, el principal afectado o influenciado es el sistema nervioso. Aunque existen diversas formas de acción de las sustancias adictivas, en general, éstas actúan afectando el pasaje dopaminérgico.
La dopamina es un neurotransmisor liberado por el sistema nervioso central que causa sensación de placer. Es conocido como la "hormona del placer" y esta relacionado con la evolución de las adicciones. Las diversas sustancias adictivas alteran el funcionamiento normal del sistema nervioso, provocando un exceso de liberación de dopamina. Esta excesiva sensación de placer al consumir sustancias adictivas es lo que nos lleva a seguir consumiendo, para repetir la experiencia placentera, generando adicción. Al hacerlo, los mecanismos de recompensa del cerebro se ven afectados, siendo la causa del elevado nivel de dopamina en el organismo. Este aumento anormal del neurotransmisor provoca una respuesta de parte del organismo que radica en disminuir la cantidad de receptores dopaminérgicos. Al hacerlo, la persona adictas sienten menos placer y mas necesidad de consumir sustancias, para alcanzar el mismo efecto de euforia o uno incluso superior.
Answer:No. This does not qualify as homeostasis because homeostasis involves the control of a physiological variable within very narrow limits so that cells can function. The body temperature of a fish fluctuates with the temperature of the external environment.
Explanation:
Fishes are poikilothemic;therefore thier body temperature fluctuates with the external environment. If the fish stays in a preferred environment momentarily, this will influence its body physiological mechanism at that moment.
Once it leaves the spot its body physiological mechanisms returns to that of the new environmental temperature,therefore fluctuating with changes of the environment.
Since homeostasis refers to a relatively constant internal environmen of an organism, prefered temperature phenomenon cannot be homestatis.!!
Answer and Explanation:
Cytokines is the molecule which has the ability to communicate with the immune system cells to target on antigen by generating a response. It is mostly comprised of protein in a group along with peptides.
They are involved in the cancer treatment by production of the signalling molecules that gets involved in the method of stimulating and mobilize the immune system and thus cytokines come into the action for preventing the cancer by providing anti-inflammatory action,anti-cancer cell etc.
<u>Example</u>- In case of ovarian cancer,there is the majority of the immuno-suppressive action and thus there is production of the anti-inflammatory cytokines and thus maintain the immune system.
Answer:
The starfish Pisaster ochraceus is a keystone species in the rocky marine intertidal communities off the northwest coast of North America. This predatory starfish feeds on the mussel Mytilus californianus and is responsible for maintaining much of the local diversity of species within certain communities. A keystone species is an organism that helps define an entire ecosystem. Without its keystone species, the ecosystem would be dramatically different or cease to exist altogether. This means that if the species were to disappear from the ecosystem, no other species would be able to fill its ecological niche.
Explanation:
Hope this helps!
