Human regulation of internal conditions. General ecosystem stability belongs in Ecology.
Test your knowledge with these top questions!
Which areas send early signals that reduce thirst as someone drinks?
These signals reach the brain before the swallowed water has had time to enter the bloodstream.
Why can heavy sweating during exercise make people thirsty?
Sweat cools skin as water evaporates, so losing heat also means losing fluid.
As a fever rises, what usually happens to a person's heart rate?
The body's energy use rises with temperature, and a faster heartbeat helps deliver the extra oxygen tissues need.
Which blood change can trigger thirst even when the mouth is moist?
The body can sense reduced circulation and release angiotensin II, a hormone that encourages drinking.
When a fever breaks, which response helps the body shed excess heat?
As the body's temperature target falls back toward normal, extra heat can leave through evaporating sweat.
During a fever, what happens to the body's target temperature?
The body can conserve heat by narrowing skin blood vessels, helping reach the higher target.
Which organ creates the conscious feeling of thirst?
A small brain region called the hypothalamus helps coordinate thirst with the body's water balance.
Which change helps the body conserve heat as a fever begins?
Less warm blood reaches the skin, so a person may look pale even while their core temperature rises.
Which urine color suggests the human body is conserving water when dehydrated?
When dehydrated, kidneys reabsorb extra water, leaving the same waste in less fluid so urine looks darker.
Which brain structure acts as the human body's thermostat?
The hypothalamus reads blood temperature and orders responses like sweating or shivering.