Edexcel iGCSE Biology-3.43 The Role of Skin in Temperature Regulation- Study Notes- New Syllabus

Role of the Skin in Temperature Regulation

🌱 Introduction

The skin helps maintain a stable body temperature (homeostasis).
It regulates heat through sweating, vasoconstriction, and vasodilation.
Works with the nervous system to respond to temperature changes.

🔥 1. Sweating (Cooling Mechanism)

• When body temperature rises, sweat glands produce sweat.
• Sweat is mostly water with salts.
• Evaporation of sweat from the skin surface removes heat → cools the body.
• Example: Exercise → increased sweating prevents overheating.

❄️ 2. Vasoconstriction (Reducing Heat Loss)

• When body temperature drops, blood vessels near the skin narrow (constrict).
• Less blood flows near skin surface → reduces heat loss.
• Skin may look paler due to reduced blood flow.
• Example: Cold weather → vasoconstriction conserves body heat.

🌞 3. Vasodilation (Increasing Heat Loss)

• When body temperature rises, blood vessels near the skin widen (dilate).
• More blood flows near skin surface → more heat radiates from body.
• Skin may look redder due to increased blood flow.
• Example: Hot weather → vasodilation helps cool the body.

📊 Summary Table

📌 Quick Recap
Skin regulates temperature via:
– Sweating → cooling by evaporation.
– Vasoconstriction → reduces heat loss in cold.
– Vasodilation → increases heat loss in heat.
Works with nervous system to maintain homeostasis.