Water Lecture Notes Flashcards

A set of vocabulary flashcards covering the molecular properties, physiological functions, regulation, and various types of water based on lecture notes.

Standard drop of water

A drop measuring $0.05\,ml$ or $0.05\,g$ which contains roughly $1.5$ to $1.7$ sextillion ($1,670,000,000,000,000,000,000$) $H_2O$ molecules.

Acid/base balance or pH of

fluids

The body uses ions not only to help maintain water balance,

but also to regulate this important metabolic function

What are dehydration and

hyponatremia?

mbalances of Water in the body: lack of and intoxication

What are Buffers?

Proteins in their role as these are used by the

body to exchange hydrogen ions to keep the

interstitial and intracellular fluids in balance

kidney and hypothalamus

Regulate water excretion

What are 2.5 L or

2.5 quarts?

Excretion of water adjusts to

balance intake. In addition to

urine, water is lost from the lungs

as vapor, some in feces, and some

evaporates from the skin. A person

water losses from all these outlets

total about this amount

What are 2 to 3 L or

8 to 12 cups a day

mount of recommended water

intake in average and depending

on many factors

What is an electrolyte solution?

Salt that dissociates in water when dissolved

What is an isotonic solution

When the solute concentration inside the cell is equal to the solute

concentration outside the cell

What is a hypertonic solution

when the water moves into the cell because salts are more concentrated

inside the cell causing the cell to swell

What is chloride

It is the major negative ion of the extracellular fluid

What is potassium

t is the principal positively charged ion inside the cells

roles of water

Carry nutrients and waste products, maintains the structure of large molecules,

participates in metabolic reactions, serves as solvent, maintains blood volume, aids in

regulation of body temperature, acts as lubricant and cushion around joints among

many others.

Body Weight Percentage of Water

Water constitutes approximately $60\%$ of an adult’s body weight.

Hypothalamus

The part of the brain that sends a signal to be thirsty when blood becomes too concentrated.

Water intake is regulated by this part of the brain by initiating thirst when water is

needed by the body

Mild Dehydration

Loss of less than $5\%$ body weight characterized by symptoms such as thirst, sudden weight loss, rough dry skin, rapid pulse, low blood pressure,

Lack of energy, weakness • Impaired kidney function • Reduced quantity of urine, and concentrated urine • Decreased mental functioning • Decreased muscular work • Fever or increased internal temp. • Fainting

Severe Dehydration

Loss of more than $5\%$ body weight characterized by pale skin, bluish lips and fingertips, confusion, disorientation, rapid/shallow breathing thickening of blood, shock, seizures, coma, death, weak/rapid irregular pulse, convulsions, kidney disorder or severe headache

Hyponatremia

A condition caused by excessive water intake (several gallons within a few hours) leading to kidney disorders, confusion, convulsions, or death.

Antidiuretic Hormone (ADH)

A hormone that stimulates the kidneys to reabsorb water rather than excrete it when salts are too concentrated or blood volume/pressure is too low.

Daily Water Excretion

The total amount of water lost through urine, feces, skin evaporation, and lung vapor, totaling about $2.5\,Lers/day$ (about $2.5\,quarts/day$).

Adequate Intake (A.I.) for Water

Between $2$ to $3\,liters$ ($8$ to $12\,cups$) per day, including water from beverages and foods.

Electrolyte

A salt that dissociates in water into charged particles called ions which conduct electricity.

Artesian Water

Water drawn from a well that taps a confined aquifer in which the water is under pressure.

Distilled Water

Water that has been vaporized and recondensed, leaving it free of dissolved minerals.

Mineral Water

Water from a spring or well that naturally contains at least $250\,ppm$ of minerals and is typically high in Sodium.

Hard Water

Water that has a high content of Calcium and Magnesium.

Soft Water

Water that has a high Sodium content.

Alkaline Water

Water with a higher pH than plain tap water, usually between $8$ and $10$, often created through electrolysis.

Buffers

Proteins used by the body to exchange hydrogen ions to maintain acid-base balance (pH of fluids).

The water in the body fluids:

➢ Carries nutrients and waste products throughout the body ➢ Maintains the structure of large molecules such as proteins and glycogen ➢ Participates in metabolic reactions ➢ Serves as the solvent for minerals, vitamins, amino acids, glucose, and many other small molecules so that they can participate in metabolic activities. ➢ Maintains the blood volume ➢ Aids in the regulation of normal body temperature (the evaporation of sweat from the skin removes excess heat from the body) ➢ Acts as a lubricant and cushion around joints and inside the eyes, spinal cord, and amniotic sac surrounding a fetus in the womb

Water balance

The cells themselves regulate the composition and amounts of fluids within and surrounding them. The entire system of cells and fluids remains in a delicate but firmly maintained state of dynamic equilibrium.

water intake regulation

When blood becomes too concentrated (having lost water but not salts and other substances) Mouth becomes dry Hypothalamus sends a signal to be thirsty (Thirst lags behind the lack of water

If water is excessively provided it leads to HYPONATREMIA (Several Gallons within a few hours)

Hypothalamus Salts too concentrated Blood volume too low Blood pressure too low Pituitary gland Antidiuretic Hormone Aldosterone (ADH) Stimulates kidneys to reabsorb water rather than excrete it (so the more water you need, the less you excrete

Body must excrete a minimum of 500 ml/day as urine- enough to carry away waste products

Water excreted in urine + feces + evaporated from skin + lost from the lungs as vapor = 2.5 Liters/day (about 2.5 quarts/day

How much water do we need? WARNING: Needs VARY greatly depending on: ✓ Foods a person eats ✓ Environmental Temperature ✓ Environmental Humidity ✓ Activity Level ✓ Health Status A.I = 2 to 3 liters (8 to 12 cups) a day Total water includes drinking water, other beverages, and water in foods

You can tell from the color of urine whether you need water Pale yellow reflects appropriate water intake Dark yellow means you need water