Human and mammals cannot survive above or below a range of critical temperature. How and from where do they obtain heat in cool time or how do they lose heat in warm condition?

1. An organism that relies on heat sources for is ectotherm. Fish are
good examples of non-regulators and so their body temperature is as the surrounding.
Some ectotherms e.g., lizards and snakes, during warm days, may achieve a closely
regulated body temperature. These animals exploit the external heat by changes.
They are vulnerable to mammals and bird predators during cold times. Therefore, less reptiles
are found in habitats where mammals have mastered.
An animal that relies on heat energy generated by is endotherm. They require more
foods than an ectotherm of size.
Respiration with other pathways generate heat as a . From the site of
production this heat reaches the rest of the body through the vessels. The bulk of the
body heat comes from heart, kidney, brain and lungs. Liver a little heat as it requires
heat being most active metabolically. In a resting body some energy will come from skin, muscle
and skeleton.
Depending on the surrounding temperature endotherm heat loss or changes metabolic
rate. Heat loss is controlled mainly by skin and changinging metabolic rate is guided by
hormones.
Body temperature can also be controlled by changes in behavior. Increasing muscle tone
the production of heat. Shivering (uncontrolled contraction) can raise muscle heat
production in cold conditions. Panting in some mammals (dogs) helps to expel heat through
mouth as they have fur which prevent effective .
Other ways of behavior to regulate body temperature are
● Moving to a hotter or colder place
● Huddling together with other individuals
● Becoming vigorously active
● Adjusting the type of clothing in humans
The amount of heat loss through the skin can be be varied to control body temperature as
following ways:
1. At capillary networks: vasodilation when the body needs to heat and
vasoconstriction if you need to heat.
2. By the hair erector muscle: contract for raising hair to a thick layer of insulating air,
but relax to more heat.
3. By the sweat glands: produce sweat to lose significant amount of .
At the the base of dermis in the skin is adipose tissue, of containing large fat stores.
This tissue has limited blood supply and is a conductor of heat. so , it insulates internal
organs against heat loss in terrestrial and aquatic mammals.
Authored to Shahidullah
4:16 AM, Aug 3, 2017
Authored to Shahidullah
4:17 AM, Aug 3, 2017
Authored to Shahidullah
4:17 AM, Aug 3, 2017
Authored to Shahidullah
4:17 AM, Aug 3, 2017
Authored to Shahidullah
4:17 AM, Aug 3, 2017