Chapter 1
The inner plumbing of thirst
Chapter 2
Busting the H2O myths
Chapter 3
The danger zone of overhydration
Chapter 4
Global adaptation and ancient wisdom
Ch 1 · The inner plumbing of thirst
doctorx Specialized brain cells called osmoreceptors detect concentration changes, releasing the hormone vasopressin to tell your kidneys to conserve water.
Quiz
Which hormone does the brain release to signal the kidneys to conserve water when you are dehydrated?
Quiz
What percentage of water loss in the human body typically triggers the brain's thirst mechanism?
doctorx Peter Agre won a Nobel Prize for discovering these selective cell membrane channels.
Quiz
Approximately how many water molecules can pass through a single aquaporin channel every second?
Quiz
Who won the 2003 Nobel Prize in Chemistry for discovering aquaporins, the cell's water channels?
Fun Fact
Aquaporin channels: They can transport up to three billion water molecules in a single second while blocking everything else.
Quiz
What color of urine generally indicates that your kidneys are actively conserving water due to mild dehydration?
Quiz
Approximately how many liters of fluid do healthy human kidneys filter every single day?
Glossary
osmoreceptor (noun)
A sensory receptor that detects changes in osmotic pressure. In 1947, E.B. Verney established that these brain cells monitor blood concentration to trigger the drinking urge.
A sensory receptor that detects changes in osmotic pressure. In 1947, E.B. Verney established that these brain cells monitor blood concentration to trigger the drinking urge.
doctorx Salt and Water Balance
Salt holds the line, water rushes in, keeping cells in balance.
Quiz
What happens to human cells when the concentration of salt in the surrounding blood drops too low?
Quiz
Which two primary minerals, known as electrolytes, are most responsible for regulating fluid balance in human cells?