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All 10 Flashcards — Thermoregulation
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Question
What is thermoregulation?
Answer
Keeping the **core body temperature** close to a set point (about **37 °C**) despite changes in the environment.
Question
Which type of feedback controls body temperature?
Answer
**Negative feedback** — the response opposes the change and returns temperature to the set point.
Question
Which part of the brain is the temperature control centre?
Answer
The **hypothalamus** — it acts as the body's thermostat.
Question
What two responses cool the body when it is too HOT?
Answer
**Vasodilation** (skin arterioles widen → more heat radiated) and **sweating** (evaporation removes heat).
Question
What responses warm the body when it is too COLD?
Answer
**Vasoconstriction** (less heat lost), **shivering** (muscle respiration makes heat) and **non-shivering thermogenesis** in brown fat.
Question
What is the difference between vasodilation and vasoconstriction?
Answer
**Vasodilation** = skin arterioles widen to **lose** heat (too hot); **vasoconstriction** = they narrow to **conserve** heat (too cold).
Question
How does brown adipose tissue raise body temperature?
Answer
By **non-shivering thermogenesis** — it **oxidises lipids** and releases the energy **directly as heat**.
Question
How does shivering raise body temperature?
Answer
Rapid **skeletal-muscle contractions** increase **respiration**, releasing **heat**.
Question
Why is vasodilation a cooling response?
Answer
Widening the skin arterioles brings **more blood near the surface**, so **more heat is radiated/lost**.
Question
Is thermoregulation an example of positive or negative feedback, and why?
Answer
**Negative feedback** — the response (e.g. sweating, shivering) **opposes** the temperature change.
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Topic 4.9 hub
Homeostasis
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