Question

When and why do blood vessels constrict in the given case set?

Answer 1

αnѕwєr

Blood vessels are automatically controlled by chemical signals in the body that tell the smooth muscles to constrict or dilate (widen). The nerve chemical messengers and hormones that tell blood vessels to constrict include: norepinephrine. epinephrine.

hσpє ít hєlpѕ