The skin, specifically the sweat glands and sebaceous glands, are directly involved in excretion.
Sweat Glands and Excretion
Sweat glands, distributed across the body's surface, release sweat. Sweat is not just water; it contains several waste products, including:
- Sodium chloride
- Amino acids
- Glucose
The elimination of these substances via sweat contributes to the body's overall excretory process.
Sebaceous Glands and Excretion
Sebaceous glands, associated with hair follicles, secrete sebum, an oily substance. While primarily involved in lubricating the skin and hair, sebum also contains waste products like sterols and waxes, contributing to a minor excretory function.
The Skin's Role in the Excretory System
The skin is one component of the body's larger excretory system, which also includes the kidneys, liver, lungs, and large intestine. Each organ plays a specific role in eliminating various waste products. The skin's contribution, although less significant than the kidneys, is nonetheless a vital part of maintaining overall body homeostasis. Reference: 16.2 Organs of Excretion – Human Biology highlights the skin's inclusion within the broader excretory system.
