Why do arteries need to be thick, muscular, and elastic?

blood flows at a high pressure, so if the arteries are thin and less muscular, the arteries can explode due to the pressure. so it needs thick and muscular properties so that it can withstand the increasing pressure of the flow of blood.

im not sure why it needs to be elastic. Hope it helped :)

the national environmental policy act (nepa) is a united states environmental law that promotes the enhancement of the environment and established the president's council on environmental quality (ceq). the law was enacted on january 1, 1970. to date, more than 100 nations around the world have enacted national environmental policies modeled after nepa.

when the displaced particles are perpendicular to the direction the wave travels, is called a transverse wave, whereas in longitudinal wave the displace practices are parallel to the direction of the wave.

in the given image:

first image shows - longitudinal wave

second image shows - transverse wave

third image shows - longitudinal wave

fourth image shows - longitudinal wave