<span>Sodium channels close when not occupied
</span><span>Sodium ions diffuse through and enter the cell.
</span>
Then they leave the cell.
The sodium diverts in the cell layer have receptor locales for acetylcholine.
There are two types of biological organization, I believe.
The first would be (from smallest to largest).
Species
Genus
Family
Order
Class
Phylum
Kingdom
Domain
The other would be:
Atom
Molecule
Cell
Tissue
Organ
Body system
Organism (Individual)
Population
Community
Ecosystem
Biosphere
Hope this helps c:
<span>A delta fibers can rapidly transmit pain information to the brain because alpha delta fiber is a type of sensory nerve fiber.
Aδ fibers carry cold, pressure and some pain signals.
Because Aδ fibers are thinly myelinated, they send impulses faster than unmyelinated C fibers, but more slowly than other, more thickly myelinated "A" class fibers.</span>