Role of Skin in Excretion — NEET Biology
📚 Practice ConceptThe sweat and sebaceous glands in the skin can eliminate certain substances through their secretions. Sweat produced by the sweat glands is a watery fluid containing NaCl, small amounts of urea, lactic acid, etc. Though the primary function of sweat is to facilitate a cooling effect on the body surface, it also helps in the removal of some of the wastes mentioned above. Sebaceous glands eliminate certain substances like sterols, hydrocarbons and waxes through sebum. This secretion provides a protective oily covering for the skin. Do you know that small amounts of nitrogenous wastes could be eliminated through saliva too?
Which of the following statements correctly explain why the skin is considered both a regulatory and excretory organ? S1: The skin's sweat glands primarily function in thermoregulation through evaporative cooling, which is a key homeostatic regulatory process. S2: Excretory substances such as NaCl, small amounts of urea, and lactic acid are eliminated via sweat glands, demonstrating the skin's excretory role. S3: Sebaceous glands contribute to the skin's protective barrier and also aid in the excretion of lipid-soluble wastes like sterols and waxes. S4: The skin actively synthesizes hormones like erythropoietin to regulate blood cell production, contributing to its regulatory capacity. S5: The skin acts as a significant storage site for metabolic waste products, thus reducing the burden on the kidneys. Choose the option containing only correct statements:
View solution & NCERT explanation
Correct answer: A — S1, S2, and S3
The core concept is to understand the dual regulatory and excretory functions of the skin based on NCERT. S1: Though the primary function of sweat is to facilitate a cooling effect on the body surface, this cooling effect is a form of thermoregulation, a key regulatory process. This statement is correct. S2: Sweat produced by the sweat glands is a watery fluid containing NaCl, small amounts of urea, lactic acid, etc. This elimination of wastes constitutes its excretory role. This statement is correct. S3: Sebaceous glands eliminate certain substances like sterols, hydrocarbons and waxes through sebum. This secretion provides a protective oily covering for the skin. Thus, they contribute to both protection (regulatory/barrier) and excretion. This statement is correct. S4: The NCERT context does not mention the skin actively synthesizing hormones like erythropoietin, which is primarily produced by the kidneys. This statement is NOT correct. S5: The skin eliminates 'small amounts' of urea and other wastes. It is not described as a 'significant storage site' for metabolic waste products to reduce the burden on kidneys, which are the primary excretory organs. This statement is NOT correct. Therefore, S1, S2, and S3 are the correct statements. This question evaluates the understanding of the skin's diverse roles, distinguishing between its regulatory and excretory functions as described in the chapter.
What does NCERT say about sweat and sebaceous glands?
Has this concept appeared in NEET?
Which chapter is this from?
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