It is sub-classified as a rough, or granular ER, and a smooth or agranular ER. The rough Endoplasmic reticulum is lined with ribosomes and modifies and packages proteins that have been produced by the ribosome. In skeletal and cardiac muscle it is known as the sarcoplasmic reticulum.
<span>The answer is a certain required chemicals must be actively
transported. Blood brain barrier is a
selective membrane that separates blood circulating from the brain and the
fluid of extracellular in the central nervous system. This is also called a
filtering mechanism, the capillaries that carry blood to the brain and spinal
cord tissue blocking the path way of the certain substance.</span>
The natural spreading of particles through a liquid or gas is called diffusion
I think that the Risk assessment depends on medicine. Here's some extra details: the PROCESS by which HAZARD, exposure and risk are determined. The four steps of risk assessment are Hazard identification<span>Dose-response assessment
Exposure assessment
Risk characterization</span>
Tranverse
longitudinal
surface
<span>and torsional waves
those are the examples to my knowledge.</span>
