nutrition chapter 11 water

What is the importance of water in the body?

Water is essential to life

What is the most abundant substance in the body?

Water

What is the average percentage of water in a healthy adult body?

45-75% water

What factors affect the percentage of water composition in the body?

Age, gender, and composition of fat and muscle

How does age affect the percentage of water composition in the body?

declines with age

Which gender has a higher percentage of water composition in the body?

Males

What is the percentage of water composition in muscle?

65%

What is the percentage of water composition in fat?

10-40%

Why is water considered a polar molecule?

neutral electrical charge

How is water used to regulate pH levels in the body?

Water is used to reduce or increase pH levels in the body

What is the role of water in maintaining acid-base balance in the body?

Water maintains acid-base balance

How does the polarity of water affect its role as a solvent?

attracts charged particles into a solution, allowing it to dissolve proteins, glucose, and some minerals

Why is water important to digestion?

helps dissolve and break down nutrients in food

What role does water play in blood?

As part of blood, water helps transport oxygen, nutrients, and hormones to cells

What role does water play in interstitial fluid?

water helps transport waste products away from cells for excretion

How does water help regulate body temperature?

Water absorbs and releases heat generated by the body

Which body parts does water act as a lubricant for?

eyes, joints, mouth, and GI tract

What body substances contain water as a lubricant?

mucus and saliva

Which body parts/organs benefit from water's cushioning effect?

brain, organs, and fetus

Which types of reactions does water participate in?

hydrolysis and condensation reactions

What role does water play in hydrolysis of molecules during digestion?

water helps hydrolyze the bonds of carbohydrate, protein, and fat molecules

How is water involved in the formation of larger molecules during condensation reactions?

Water is formed and released when smaller molecules join together

How is water balance maintained in the body?

through fluid balance (homeostasis)

Why is fluid balance important for the body?

necessary for normal reactions within the cells

What is the result of balanced water intake and losses?

result in maintaining water balance in the body

What are the sources of body water in the body?

beverages and food

Which source of body water is the largest?

Beverages

Do all foods contain water?

Yes

Which types of foods contain the most water?

Fruits and vegetables

What is metabolic water?

Water generated during metabolism

What is the average daily intake of water from these sources?

2,550 milliliters (about 2 quarts)

How is water excreted from the body?

through the kidneys, large intestine, lungs, and skin

What is the largest route of water excretion from the body?

through the kidneys as urine (sensible water loss)

Is urine production dependent on water intake?

Yes

Where else is water lost from the body besides the kidneys and large intestine?

through intestinal fluids in the stool, evaporated through exhalation, and through the skin (insensible water loss)

Can plant fibers reduce water excretion?

Yes

Can diarrhea and vomiting increase water excretion?

Yes

How does sweating impact water loss from the body?

can result in water loss

What factors can impact water loss through sweating?

* temperature
* humidity
* wind
* sun's intensity
* clothing worn
* amount of physical activity

Where is body fluid located?

intracellular fluid (ICF) and extracellular fluid (ECF)

Where is intracellular fluid (ICF) located?

within the cells

What are the two types of extracellular fluid (ECF)?

interstitial fluids, which bathe the outside of cells, and intravascular fluids, which are found in blood and lymph

Do fluids move easily between ECF and ICF?

Yes

What are electrolytes?

minerals with charged ions that conduct electrical current

examples of electrolytes

potassium, phosphate, magnesium, calcium, chloride, and sodium

what role do electrolytes play in fluid balance?

They help maintain water balance between compartments, especially sodium

What is osmosis?

the movement of water or any solvent between the cell's semipermeable membrane, not the solutes

In osmosis, how does water move in relation to concentration of electrolytes?

from a diluted concentration to a high concentration of electrolytes

What does osmotic pressure control?

directional flow of water

What is osmotic pressure based on?

osmolality or the concentration of particles in a solution (number of solutes)

What is the role of the sodium-potassium pump in fluid balance?

helps maintain normal electrolyte concentrations, which is essential for fluid balance

How do electrolytes aid in electrical conduction in nerve and muscle cells?

help create an electrical charge across cell membranes, which is necessary for the proper function of nerve and muscle cells

How do electrolytes aid in nutrient absorption?

help transport nutrients across cell membranes

What is the role of proteins in fluid balance?

proteins attract fluid from the interstitial spaces into the vascular space

How does albumin regulate fluid balance?

Albumin in the vascular space attracts fluid from the interstitial spaces

What is hyponatremia?

a condition characterized by low sodium levels in the blood

What does hyponatremia reflect?

hyposmolality, which is a low concentration of solutes in the blood

How does water overload occur in hyponatremia?

when water input exceeds water output, leading to water retention in the body

What is hypernatremia?

condition characterized by high sodium levels in the blood

What does hypernatremia reflect?

hyperosmolality, which is a high concentration of solutes in the blood

How does water depletion occur in hypernatremia?

when water output exceeds water input, leading to a deficit of water in the body

What does the plasma sodium concentration indicate?

reflects the water status in the body, rather than the sodium status

What is the effect of hyperosmolality on antidiuretic hormone (ADH) release?

stimulates the release of ADH

How does ADH affect the kidneys?

tells kidneys to reabsorb more water

What is the overall effect of ADH on blood volume and blood pressure?

ADH increases blood volume and blood pressure

What is the role of the kidneys in blood volume regulation?

they sense a drop in blood volume and release renin, which helps regulate blood pressure

What does renin activate?

activates angiotensinogen to angiotensin I.

Where is angiotensin I converted to angiotensin II?

lungs

What is the effect of angiotensin II?

acts as a vasoconstrictor, which increases blood pressure

How does angiotensin II stimulate aldosterone release?

stimulates the adrenal glands to release aldosterone

What is the role of aldosterone in blood volume regulation?

signals the kidneys to reabsorb more sodium, which increases blood volume and blood pressure

What is the overall effect of renin-angiotensin-aldosterone system (RAAS) on blood volume and blood pressure?

increases blood volume through sodium and water reabsorption and vasoconstriction

What are diuretics?

substances that increase the production and secretion of urine

What is the effect of caffeine on fluid balance?

mild diuretic that does not negatively upset fluid balance

How does alcohol interfere with water balance?

inhibits ADH, which can lead to dehydration

What is the effect of medications that inhibit Na reabsorption?

can increase urine output and help reduce fluid volume in the body

What is the overall effect of diuretics on fluid balance?

increase urine output, which can help reduce fluid volume in the body and decrease blood pressure

What is dehydration?

drop in body water, causing blood volume to decrease

What can cause dehydration?

inadequate water intake, too much water loss, diarrhea, strenuous exercise in hot conditions, vomiting, high fever, and use of diuretics

What are some potential effects of dehydration?

reduced blood pressure, hypotension, reduced cardiac output, impaired digestion, fainting or blackout

What % loss of body water can impact cognitive function

2

What is the effect of loss of body water on cognitive function?

short-term and long-term memory, lower attention span and cognition, and reduced ability to maintain core temperature

What is the increased risk associated with dehydration?

urinary tract infections

How does dehydration affect athletic performance?

can impair athletic performance by reducing endurance, increasing perceived exertion, and reducing power and speed

What is water intoxication?

distribution of water among body compartments is affected, leading to an imbalance of electrolytes

Is water intoxication common in individuals who eat a healthy, balanced diet?

No

What is hyponatremia and what is its relation to water intoxication?

low sodium levels in the blood, which can occur as a result of water intoxication without adequate sodium replacement

What are the symptoms of water intoxication?

nausea, muscle cramps, disorientation, slurred speech, confusion, seizure, coma, and even death

When should sports drinks be used?

if an individual is doing cardio for more than one hour to help replace lost electrolytes and fluids

How can hydration status be assessed?

by monitoring water intake and urine color

What is the recommended amount of water to consume for each pound of water weight lost?

16 oz of water to maintain proper hydration levels

What is the adequate intake values for men in terms of daily beverage recommendations?

3\.7 L/d (16 cups/d)

What is the adequate intake values for women in terms of daily beverage recommendations?

2\.7 L/d (12 cups/d)

Are there higher daily beverage recommendations during pregnancy and lactation?

Yes

What percentage of daily fluid intake should come from beverages?

80%

What is the recommended daily intake of cups of water from beverages for men

13 cups/day

What is the recommended daily intake of cups of water from beverages for women?

9 cups/day

What factors influence an individual's water needs?

physical activity, environmental factors, and diet

What are the best sources of water?

bottled or tap water, milk, and juices, which should be consumed throughout the day

Can food contribute to meeting daily water needs?

Yes