7. Muchas de las neuronas están rodeadas y protegidas por ciertas células que actúan como tejido de sostén, facilitan la nutrición de las neuronas y la eliminación de sus desechos metabólicos,

contribuyen a su defensa y actúan como guías para el desarrollo neuronal, además de proveer la

vaina de mielina. Estas células se denominan:

a. Neuronas b. Células gliales c. Células sanguíneas d. Células musculares

8. Las células Gliales Microglia tiene como característica

a. Forman parte del sistema locomotor b. Forman la vaina de mielina

c. Son capaces de iniciar una respuesta inflamatoria d. Forman la barrera hematoencefálica.

9. Al remover la vaina de mielina del axón de una neurona, el resultado más probable es que la neurona:

a. Sea más sensible a los estímulos b. Sea menos sensible a los estímulos.

c. Transmita señales nerviosas con mayor rápidez d. Transmita señales nerviosas con menor rápidez.

10, La Vaina de Mielina se ve interrumpida por:

a. Células de Schwann b. Oligodendrocitos c. Nodos de Ranvier d. Astrocitos

(auxilio ;-; ...) ​

phylogenetic tree is the tree of life or evolution tree. it shows the different branches of evolution. the sequence goes like tissues - coelom - backbone - endoskeleton - segmentation

cells use diffusion to get substances in and out of themselves. that diffusion will occur across the cell membrane or the outer covering of the cell. because we are talking about the surface of the cell, surface area and volume are  important factors here. as a cell increases in size, its surface area and volume increase as well.  we call that the surface area to volume ratio (sa: vol).  but the catch is that  volume increases at a greater rate than surface  area. in other words, as a cell gets bigger, the sa: vol gets smaller. so a really small cell like bacteria is mostly cell membrane (surface) with very little contents (volume). a really big cell like an egg, is mostly insides with a super thin membrane. so what ends up happening is that the cell cannot efficiently diffuse all of the stuff it needs in/out to survive. therefore cell size is limited to about 100mm. so how do we make organisms bigger than 100mm? cells divide! by dividing and becoming multicellular, organisms are able to grow!   check out the diagrams i attached to see the effect of sa: vol. i hope this ! good luck!

if you add everything up correctly you should get 69 i got this because 50 plus 19 is it