Water and Hydration Lecture Notes

A set of vocabulary flashcards based on lecture notes regarding the biological importance, regulation, and functions of water in the human body.

Body Weight Percentage of Water

Water makes up between 45\text{-}75\text{%} of body weight, depending on the amount of fat and muscle present.

Universal Solvent

A role of water where it acts as a cleansing agent, carrying out waste matter and moving nutrients like water-soluble vitamins around the body.

Osmoreceptors

Sensors in the hypothalamus that monitor the sodium concentration or osmolarity of surrounding fluids to stimulate thirst.

Angiotensin II

A hormone that stimulates antidiuretic hormone to help stabilize blood pressure and signals the kidneys to retain water and sodium.

Antidiuretic hormone

A hormone released by the pituitary gland that signals the kidneys to reabsorb more water when sodium concentration rises.

Thirst Mechanism in Older People

A system that can weaken with age, potentially leading to dehydration.

Hydration Status Gauge

A method of checking hydration by observing urine; adequate hydration results in clear or pale, odorless urine, while low intake leads to concentrated color and odor.

pH Balance

A function of water involving adjusting or raising acidity when pH levels rise above normal limits.

Water Content of Muscle

Muscle tissue consists of 75\text{%} water, meaning leaner individuals have higher hydration and water needs.

Influence of Environment on Water Needs

The warmer the climate, the more the body uses perspiration to cool down, increasing the need for water to maintain balance.

Water Intake Sources

75\text{-}80\text{%} of water comes from fluids (with water being the best source), while 20\text{-}25\text{%} comes from foods, especially fruits and vegetables.

Insensible Water Loss

The evaporation of water from the lungs and skin, estimated at $\frac{1}{4}$ to $\frac{1}{2}$ of daily fluid loss.

Special Circumstances for Increased Fluids

Conditions such as endurance athletics, pregnancy, and breastfeeding that require higher than typical water intake.

Special Circumstances for Limited Fluids

Medical conditions such as certain stages of renal disease and heart failure where fluid intake must be restricted.