分辨 bio terms 幾時用constriction 幾時用contraction?

constriction同dilation係講中空既結構
譬如血管
contraction同relaxation係講實心既結構
譬如肌肉

At high temperature, in order to promote heat loss, arterioles dilate and erector muscles relax. At low temperature, arterioles constrict and erector muscles contract so as to reduce heat loss.

1.constriction and dilation
多數係指不是muscle的狀態
2.contraction and relaxation
多數係指muscle的狀態

example用眼就最好
pupil(個洞洞) in light condition= constriction (個洞細左)
因為circular muscle(muscle黎) contract
radical muscle就要relax
咁就入少d光入眼,唔好整壞眼中既rods and cones

相反
pupil(個洞洞) in dark condition= dilation (個洞大左比多d light 入去)
radical muscle要contract
circular muscle relax