Water and Electrolytes

2 major components that water is found in

intracellular, extracellular

Intracellular makes up …

60% of body water

Extracellular makes up …

40% of body water

Extracellular body water includes

interstitial fluid & intravascular fluid

The minimum water excretion is about … per day

500 milliliters

… and … influence water intake in response to changes sensed by the mouth, hypothalamus, and nerves

thirst and satiety

Dehydration

when too much water is lost from the body and not replaced

Water intoxication

excessive water intake within a few hours leading to hyponatremia

Hyponatremia

low sodium in blood

Symptoms of water intoxication

confusion, convulsions

Most fruits and veggies contain … of water

90%

Many meats and cheeses contain at least …

50%

Metabolic water

generated as an end product during condensation reactions and the oxidation of energy yielding nutrients

Water recommendations

1-1.5mL/kcal

Physically active and hot climates does what to water needs

makes it higher

caffeine and alcohol acts as

diuretics

Hard water has high concentrations of

calcium and magnesium

Soft Water has high concentrations of

sodium or potassium

Water is a(n) … nutrient

essential

Does the body have a water storage mechanism

NO

Water consumption is required everyday (T/F)

True

Water fluctuation in the body is common. Why?

the body does not have a water storage mechanism

Critical functions of water in the body (3)

body temperature regulation, water absorbs body heat, heat released at skin via sweat

The … in the brain controls the body’s perceived need for water

hypothalamus

Thirst is triggered when

water levels drop and solute concentrations increases

What are the two hormones that help maintain hydration

antidiuretic hormone; aldosterone

Antidiuretic hormone

released by pituitary gland to signal kidneys to retain water

Aldosterone

Produced by adrenal glands above the kidneys. Induces kidneys to retain sodium and water

Dehydration can occur from (2)

excessive water loss via sweat; vomiting and diarrhea

Is the body’s function altered at all levels of dehydration

YES

Mild dehydration

thirst, some lack of mental clarity, and mild fatigue

Moderate dehydration

reduced athletic ability

Severe dehydration

cramping and heat exhaustion

If water loss continues then …

hallucinations and heatstroke occur

Urine is the primary path for (2)

Water loss and excretion of metabolic waste, regulation of extracellular fluid composition

The … controls urine and blood composition

kidney

Nephron

microscopic structures that filter blood; 1 million in each kidney

Composition of Urine

water and electrolytes; urea and creatinine

Water and electrolytes are moved across cell walls through what 2 processes

diffusion and osmosis

Diffusion

movement from area of greater concentration to area of lesser concentration

Osmosis

movement of water across membrane from area with fewer particles to an area with more particles

Functions of electrolytes in acid-base balance (pH)

maintenance of normal blood pH

Functions of electrolytes in nerve transmission

sodium and potassium have charges when dissolved in water which assist in function of excitable cells in nerves; sodium moves into the cell and potassium moves out

Functions of electrolytes in gastric pH

hydrochloric acid contains chloride; protein digestion; absorption of some minerals

The principal cation of the extracellular fluid

Sodium

AI for sodium (age<51)

1500 milligrams/day

AI for sodium (age> 70)

1200mg/day

CDDR for sodium

2300mg

The average sodium intake for adults in the United

3400 mg

Relationship between sodium and hypertension

high sodium leads to high BP

Relationship between sodium and bone loss (osteoporosis)

high salt intake is associated with increased calcium excretion

Sodium food sources

processed foods

Sodium deficiency

Blood sodium might drop with vomiting, diarrhea, overhydration, or heavy sweating

Hyponatremia

a dangerous droop in blood sodium levels, often during intense or prolonged activity

Symptoms of hyponatremia

headache, confusion, stupor, seizures, and coma

Sodium toxicity is iffy because

an UL is not established

Is the primary source of sodium the salt we add in our foods (yes/no and WHY)

NO, main dietary source is processed foods (77%)

Chloride (4)

Major anion of extracellular fluids; moves passively across membranes, associates with sodium and potassium, helps maintain fluid and electrolyte balance.

In the stomach chloride is part of … which …

hydrochloric acid; maintains the strong acidity of gastric juice

Chloride recommendations

slightly higher than, but still equivalent to that of sodium

Chloride food sources

processed foods

Chloride deficiency and toxicity

diets rarely lack chloride, conditions can lead to deficiency, toxicity is due to water deficiency

Potassium is a … ion

positive

Potassium roles

helps maintain fluid and electrolyte balance; maintain cell integrity, aids nerve impulse transmission and muscle contraction

Potassium recommendation and food sources

The AI for potassium is 4700mg per day

Richest sources of potassium

fresh foods

Most processed foods contain (more/less) potassium

less

Potassium relationship with hypertension

may support a healthy blood pressure

Potassium deficiency basic symptoms

characterized by an increase in blood pressure kidney stones, and bone turnover

Potassium deficiency advanced symptoms

irregular heartbeat, muscle weakness, and glucose intolerance

Potassium toxicity

with more potassium than the body needs the kidneys accelerate excretion

If potassium is injected into a vein then …

the heart can stop

Electrolytes

salts that dissociate into ions.

Fluids that contain electrolytes

electrolyte solutions

Electrolytes attracts …

water

Osmotic pressure

the amount of pressure needed to prevent the movement of water across a membrane

How do proteins attract water

proteins leak out of the blood vessels into the spaces between the cells

Vomiting/Diarrhea causes … loss

sodium

Excess aldosterone causes … loss

potassium

Uncontrolled diabetes causes … loss

fluid and glucose

Oral rehydration therapy (ORT)

mix of sugar, salt, and water

Sugar and salt do what to water absorption

they increase it

Nerve transmission

Sodium is pumped into the cell to start action potentials in a cell (alters charge of neuron to be more positive) >Potassium leaves the cell in response to sodium entering the cell. To reset sodium is pumped out while potassium comes into the nerve

Systolic blood pressure

peak pressure generated when the heart contracts and forces blood to move

The 2 components of blood pressure are

Systolic and Diastolic BP

Diastolic blood pressure

lowest blood pressure reading during cardiac relaxation

Diagnosis of hypertension is related to

an elevation fo blood pressure

DASH

dietary approaches to stop hypertension

In DASH increased fruits and vegetables

increases potassium intake

In DASH increased whole grains

Increases magnesium intake

In DASH low fat dairy

increases calcium intake