How the body regulates
What part of the brain controls body temperature?
The hypothalamus controls body temperature.
What is the main way the body loses heat when it's hot?
by sweating and releasing heat through evaporation.
You walk outside on a hot summer day, and you start sweating. How does sweating help regulate your temperature?
Sweating cools the body through evaporation, which removes excess heat.
What is the normal average body temperature for humans?
98.6°F
What is Hypothermia?
Hypothermia is when the body's core loses heat faster than it can generate it.
How does the body cool itself down when it gets too hot?
The body sweats and blood vessels near the skin widen (vasodilation) to release heat.
What is conduction in terms of heat loss?
Conduction is when heat transfers directly from the body to a cooler surface it touches.
You step into an air-conditioned room after being outside in the heat, and you notice goosebumps fading away. Why does this happen?
Goosebumps help trap warm air when you’re cold, but once you’re in a cooler, controlled environment, your body no longer needs them.
Which part of the brain controls body temperature?
The hypothalamus
What is the main cause of hyperthermia?
Hyperthermia is usually caused by prolonged exposure to high heat/activity in hot conditions, which can prevent the body from cooling down correctly.
What happens to muscles when the body gets too cold?
Muscles "shiver", which creates extra heat through rapid contractions.
How does convection cause heat loss from the body?
Convection happens when moving air or water carries heat away from the body.
A runner finishes a race in the heat, and their face is red. What is happening in their body to cause this?
Blood vessels near the skin widen (vasodilation) to release more heat.
Why does the body shiver when it gets too cold?
Shivering produces heat through rapid muscle contractions, helping to raise body temperature.
What are two common symptoms of hypothermia?
Shivering and confusion are two common symptoms of hypothermia.
Why does vasoconstriction help the body when it's cold?
Vasoconstriction narrows blood vessels near the skin, reducing blood flow and heat loss, which helps keep core organs warm.
Why is evaporation significant for heat loss during exercise?
Evaporation of sweat removes large amounts of heat, which prevents overheating when the body produces extra heat from muscle activity.
A person falls into icy water. What immediate response does their body trigger to prevent heat loss?
The body causes shivering to generate heat and constricts blood vessels (vasoconstriction) to conserve core temperature.
What happens to blood vessels near the skin when the body is too hot, and why?
They widen (vasodilation) to increase blood flow to the skin, releasing more heat into the environment.
Why can hyperthermia be more dangerous if a person is dehydrated?
Dehydration reduces the body's ability to sweat and release heat, making it harder to cool down and increasing the risk of organ failure.
How does the body's temperature control system help regulate body temperature?
It detects changes in body temperature and triggers opposite responses, which bring the body back to a stable balance (homeostasis)
How do the four methods of heat loss(conduction, convection, radiation, and evaporation) work together to maintain body temperature?
Together, these processes prevent the body from overheating and help keep a stable temperature.
During a fever, the body raises its internal set point temperature. Why does a person first feel chills, then later sweat as the fever breaks?
At the start, the body feels cold and shivers to reach the new higher set point. When the fever ends, the set point drops, and the body sweats to release extra heat and return to normal temperature.
How does the body maintain homeostasis when faced with both external temperature changes and internal heat production (like exercise)?
The hypothalamus detects temperature changes and triggers mechanisms such as sweating, shivering, vasodilation, or vasoconstriction to balance heat loss and heat production, keeping body temperature stable.
Both show that when the body cannot maintain a stable core temperature, normal cellular functions break down, which can lead to confusion, organ damage, and possibly death. This proves thermoregulation is vital for survival.