Question

In extremely cold conditions people may get frostbite. This causes the cells in the toes and fingers to die. Explain why this takes place even if thick gloves, socks and shoes are worn. [O Level Nov 2008 5094/2]

Answer 1

Because your hands and feet as well retriceother body parts are further from the heart so by the time the blood as pumped to your extremities, it has already lost most of its heat.

Answer 2

Thanks :P

Answer 3

This might be a bad comparison but think about the engine in a car. It gives off a ton of heat to the surrounding parts but parts further away such as tires or car doors do not absorb this heat. Same with your heart, its pumping, circulating, and radiating heat to the surrounding areas but your fingers and toes are too far to get that heat.

Answer 4

i am sorry but trey hughs has got it wrong this time.
the main thing is vasoconstriction. in order to preserve core temperature, blood is shifted from the periphery (extremities) to the torso, head, etc. this happens through vasoconstriction. less blood reaches the periphery , thus heat is not lost, rather preserved in the core - and not in the hands for example. less blood, thus less heat reaches the periphery to start with. gloves etc, wont help - they insulate, but in order for insulation to be effective heat (in that sens blood) needs to get there at first.
by the way - that is why the periphery gets blue - ie cyanotic, in peripheral cyanosis (unlike central cyanosis which truly rises from hypoxia), less blood is pumped to the periphery, thus the oxygen extraction ratio is higher, thus we turenblue

Answer 5

agreed with ttom. the bloodflow to your appendages decreases in order to keep blood in your torso. also i believe you Heart rate decreases to conserve energy.