Question

Primary function of sweat glands is
A) Thermoregulation
B) Excretion
C) Osmoregulation
D) None of the above

Answer 1

Hint: The mammals’ skin consists of almost four million sweat glands that secrete fluids called sweat. These are of two types which are, the eccrine glands which are the most widely distributed and the apocrine glands. The action of these glands varies from infant to adult and also varies from men to women.

Complete answer:
In sweat more than ninety-nine percent is water and the remaining are urea, uric acid ammonium chloride and sodium chloride salts. In sweat, lysozyme is also present, which destroys the bacteria.
The smell in sweat is due to the fatty substances. Evaporation of this sweat requires a lot of heat. Thus, evaporation of sweat can bring down the temperature which is an important thermo-regulatory adaptation in terrestrial vertebrates.

Sweat glands in the skin secrete sweat or which is also called perspiration; but, its primary functions are temperature control and release of pheromone. Hence, its role in excretion is minimal. Sweat glands regulate temperature and also remove waste by secreting water, sodium salts, and nitrogenous waste like urea onto the skin surface.

As we know osmoregulation is the maintenance of constant osmotic pressure in the fluids of an organism by the controlling of water and salt concentrations. The thermoregulatory mechanism that affects body fluid homeostasis is evaporative cooling, which is caused by sweating or panting, to dissipate heat from the body when the core temperature is elevated. The preoptic region of the brain has an important role in osmoregulatory and thermoregulatory mechanisms.

Therefore, the correct option is option ‘A’.

Note: Excessive sweating is known as hyperhidrosis where excessive sweating from hands, armpits, feet, and sometimes from groins begins. The absence of sweating is called anhidrosis. Hyperhidrosis is a disorder and a symptom of different diseases like endocrine diseases, neurologic and also other systemic diseases.