Moderate

Sweating cools the body because

Correct answer: D. evaporation of the water in sweat takes latent heat from the skin

  • A. sweat is colder than the body
  • B. sweat carries away dissolved urea
  • C. the sweat glands use up energy in secreting it
  • D. evaporation of the water in sweat takes latent heat from the skin

Explanation

Changing liquid water into vapour requires a large amount of latent heat, and that heat is drawn from the skin surface, so the body cools only when the sweat actually evaporates. This is why sweating is far less effective on a humid day, when evaporation is slow and the sweat simply drips off. Sweat leaves the body at body temperature, so it is not cold when secreted.

Written and checked by , contributorLast updated
Report an error

The more specific you are, the faster it gets fixed. A source beats an opinion.

Prefer email? support@testustad.com

About Thermoregulation

Thermoregulation maintains body temperature through negative feedback controlled mainly by the hypothalamus. It covers vasodilation and vasoconstriction, sweating, shivering, changes in metabolic heat production and behavioural responses, while distinguishing heat loss by radiation, conduction, convection and evaporation from temperature regulation itself.

Practise Homeostasis

698 free Homeostasis MCQs from Biology, each with the correct answer and an explanation. Unlimited attempts, no account needed.

Discussion

Stuck on an option, or know a faster way to get there? Ask or explain it here.

No comments yet. Be the first to explain this one.

Exams that ask Biology questions like this

Biology is on 8 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.

More Thermoregulation questions