Chapter 9: Water and Hydration Flashcards
What is water, and what are the different sources and storage places for it in the body?
Water makes the majority of our body. Our body is around 50 – 60% water.
Water is made up of one oxygen molecule surrounded by two hydrogen molecules. The chemical structure makes water polar. One side of it has a positive charge while the other has a slight negative charge. Due to this polarity, water is able to interact with many other molecules by weakening forces that bond them. It also has a high specific heat. The overall volume of water in the body is known as the total body water.
We divide total body water into intracellular and extracellular water. Intracellular is the water inside the cells of the body. Extracellular water is the water outside the cells in the body. We can split that up into both interstitial and plasma volume.
- What is homeostasis?
Water is a key part of the maintenance of homeostasis. This is the ability for the body to keep itself at a stable equilibrium between processes that are dependent on each other. The transfer of fluids is driven through osmosis, which is when molecules pass through a semipermeable membrane from areas that have a high concentration, to the areas with a lower one.
What three hydration statuses exist?
Euhydration is a state of adequate body water regulated by the brain.
Hyperhydration is a state of having excessive total body water content.
Hypohydration is a state of decreased levels of total body water. It is dehydration, essentially.
Underhydration is the state at which hormones used to regulate fluid balance are activated, but total body water is not reduced too much.
- How can we look at urine to determine the level of hydration? Is this effective?
Urine color is one of the ways we can look at the hydration statuses. This can be done as a test, or as a simple color examination. A urine osmolality and plasma measurement requires the person to have access to expensive equipment, where large values indicate concentrated urine and small values indicate diluted urine. Urine specific gravity and color are inexpensive. Urine color is the easiest way to self-assess your hydration. The scale simply goes from clear to severely dehydrated, or white to a dark yellow/brown.
- In what way is kidney health affected by hydration?
The relationship between water intake and urine production shows a clear link between health of kidneys and hydration. The more water you intake, on average, the better the health of your kidneys will be. This is because the more water we take in, the more urine it produces. It becomes easier to filter and reduce the presence and risk for kidney stones in these greater hydration levels.
- What roles are played by water in the body?
The roles of water in the body:
a. Cellular metabolism
b. Temperature regulation
c. Solute balance
d. Transportation of nutrients
e. Cellular waste clearance
f. Maintaining homeostasis
g. Digestion
h. Balancing pH
i. Waste elimination
j. Oxygen delivery
- What steps will allow us to estimate the amount of fluid needed during exercise or
athletic performance most accurately?
These steps allow for good estimation of fluid needed for exercise can be found by:
i. Measuring the nude body weight in a euhydrated state.
ii. Carefully tracking the weight of all fluid and food intake during activity.
iii. Weighing any urine or fecal matter produced during the activity if
possible.
iv. Removing any remaining sweat from the skin surface after exercise.
v. Using the same scale, obtaining a second nude body weight.
How many ounces of water are recommended to be consumed per pound of fluid loss?
recommendation for replacing fluid losses is 20 to 24 ounces per pound
