Kaplan Nursing Entrance Practice Exam

What substances do sweat glands secrete?

1. Only water

2. A mixture of water, salt, and urea

3. Pheromones and oils

4. Carbon dioxide and ammonia

The correct answer is: A mixture of water, salt, and urea

Sweat glands play a crucial role in thermoregulation and excretion in the body. They primarily secrete a mixture of water, salts (primarily sodium chloride), and urea. This combination helps in cooling the body when sweat evaporates from the skin surface, and the salts and urea are waste products that the body excretes through perspiration. Water is the main component, serving to hydrate the skin and facilitate cooling. The presence of salts and urea not only aids in the excretion process but also results in the characteristic salty taste of sweat. This is why a mixture of water, salt, and urea is accurately represented as the primary substance secreted by sweat glands. Understanding this function is vital when considering the physiological processes related to temperature regulation and waste management within the human body.