2007-03-12 02:27:44 · 7 answers · asked by Anonymous in Science & Mathematics ➔ Zoology
Evolution!
2007-03-12 02:34:45 · answer #1 · answered by Anonymous · 3⤊ 1⤋
Mechanisms that stop a penguin’s feet from freezing are:
The flow rate of the blood to the feet is altered by the blood vessels that supply the feet. There are changes in the diameter of the vessels according to the temperature. When it is cold the flow is reduced and when it is warm the flow is increased.
There is also a counter current heat exchange that occurs at the top of the legs. The blood vessels that supply the feet with warm oxygenated blood are further divided into smaller vessels and contact the blood vessels that take away the cold deoxygenated blood closely. The heat that is lost from the warm supplying vessels is picked up by the leaving blood vessels and transported into the body rather than out of the feet. The extremities are therefore supplied with oxygenated blood but heat is not lost through the skin.
A penguin’s feet temperature is held a couple of degrees above freezing to avoid frostbite but minimizing heat leaving the body.
2007-03-12 03:14:41 · answer #2 · answered by onyx27 3 · 0⤊ 1⤋
Penguins and many other water birds have what is known as a counter-current heat exchange system. The warm blood flowing into the leg warms up the cold blood going back to the body. This minimizes the amount of heat loss. As well they are able to control the blood flow in order to insure that the feet don't actually freeze.By doing this they minimize the amount of heat lost to the environment. If it's very cold they will bring their feet into the feathers and help keep them warm. The muscles on a bird's leg are located closer to the body in feathered areas where they are not as prone to frost damage, the feet are controlled by tendons.
2007-03-12 02:34:39 · answer #3 · answered by crazy.carabid 4 · 3⤊ 1⤋
Penguins reduce blood flow to their feet by varying the diameter of arterial vessels. This keeps their feet a degree or two above freezing, minimising heat loss, while escaping frostbite.
.... Apparently.
2007-03-12 02:36:56 · answer #4 · answered by brianthesnailuk2002 6 · 0⤊ 2⤋
Because they are very dehydrated. Their feet are mostly tough, leathery skin and little blood, so they "feel" less and absorb less of the icy cold temperature.
2007-03-12 02:31:29 · answer #5 · answered by glacier_kn 3 · 0⤊ 2⤋
layers of fat in thick padded feet with fat veins that pump a lot of warm blood
2007-03-12 08:50:31 · answer #6 · answered by Anonymous · 0⤊ 2⤋
They wear wing tips!
2007-03-12 02:39:00 · answer #7 · answered by ? 4 · 0⤊ 2⤋