Water and Body Functions Quiz

Study Notes

Water is a vital nutrient, more important than other nutrients.
An adult's body is roughly 60% water, while children have a higher percentage.
The body maintains fluid balance and distribution with the help of minerals.
Water is the medium for all life processes in the body.
Water carries nutrients and waste products.
Water participates in metabolic reactions.
Water maintains blood volume.
Water aids in regulating body temperature.
Water serves as a solvent for minerals, vitamins, amino acids, glucose, and other molecules involved in metabolic processes.
Water acts as a lubricant and cushion for joints, eyes, spinal cord, and the amniotic sac during pregnancy.

Thirst and satiety regulate water intake based on signals from the mouth, hypothalamus, and nerves.
Water intake sources include beverages (550-1500 ml), foods (700-1000 ml), and metabolism (200-300 ml), resulting in a total water intake of 1450-2800 ml.

Water loss sources include kidneys (urine, 500-1400 ml), skin (sweat, 450-900 ml), lungs (breathing, 350 ml), and the gastrointestinal tract (feces, 150 ml).
The total water loss is 1450-2800 ml.

Dehydration is the state when water loss exceeds water intake.
Symptoms of dehydration include thirst, dry skin, mucous membrane issues, rapid heartbeat, low blood pressure, and weakness.
Water intoxication is a rare condition where the body has too much water.

The recommended water intake for a person consuming 2000 kcalories a day is 2-3 liters.
This recommendation aligns with the adequate intake (AI) for water established by the Dietary Reference Intake (DRI).

Two-thirds of body fluids are inside cells.
One-third of body fluids are outside cells.
Some electrolytes reside primarily outside of cells.
Other electrolytes reside primarily inside of cells.
Cell membranes are selectively permeable, allowing specific molecules through.
Water movement is regulated by electrolytes.
Cell rupture can occur with excess water entering; collapse occurs with too much water leaving cells
Electrolytes (like sodium, chloride, potassium, calcium, phosphorus, magnesium and sulfur) move across the cell membranes, causing water to follow to maintain balance.