Extreme cold causes blood vessels to constrict, a process known as vasoconstriction. This reaction helps to conserve body heat by reducing blood flow to the skin and extremities, minimizing heat loss. Prolonged exposure to extreme cold can lead to reduced circulation, increasing the risk of frostbite and other cold-related injuries.
veins
VEINS
The artery does
Capillaries.
they bring oxygen to the brain
cappilleries
the pulmonary veins
OK, by definition we have blood. Do you want to know what blood is made of?
There are 96 000 km
2
The Artery
atherosclerosis