Water and Body Functions Quiz

Water

• 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.

Water Balance and Intake

• Intracellular fluid is the fluid inside cells.
• Extracellular fluid is the fluid outside cells.
• Every cell contains the specific fluid composition needed for optimal function.
• Intracellular and extracellular fluids have different compositions.
• The composition of these fluids remain constant under normal conditions.
• Imbalances in water balance can be harmful.
• The body regulates water intake and excretion to maintain homeostasis.
• Homeostasis is the dynamic equilibrium in a balanced system.

Water Intake

• 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 Losses

• 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 and Water Intoxication

• 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.

Water Recommendations

• 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).

Fluid and Electrolyte Balance

• 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.