NBCD - Water and Electrolytes

30 L

ICF is approx _____

15-17 L

ECF is approx ______

K +

The major cation of ICF

Phosphate

Major anion of the ICF

Na+

Major cation of the ECF

Cl-

Major anion of the ECF

Intravascular Fluid Compartment

All fluids within blood vessel ~3L

Vitreous humor

Fluids in the eyeball

Synovial Fluid

fluid around joints that allow for easier movement and to reduce friction

Thirst and satiety

Rules H2O intake

Brain (cells of hypothalamus and pituitary gland) and kidney

Mechanism of the water excretion involves what organ/s

1. Ctrl of fluid intake

2. Ctrl of the rate of fluid lost through the kidneys

Water/fluid balance is achieved through:

Angiotensin, ADH (anti-diuretic hormone), and aldoesterone

Hormones that maintain fluid balance

Dehydration

Condition resulting form excessive water loss + electrolyte losses

overhydration

Also called water intoxication; results from excessive fluid intake without an equivalent amt of salt

Renin

An enzyme in the kidney that is secreted in response to low renal blood flow; converst plasma proteins Angiotensin I to Angiotensin II

Aldosterone

Hormone from the adrenal cortex that stimulates Na-retention

Vasopressin (or ADH)

Secreted by the pituitar gland; retains water

At least 2.5 L of water daily; 1 mL per kcal of E-expenditure

RNI of water to compensate for water losses

Anions

negatively charged ions; Chloride, bicarbonates phosphates, and sulfates

Cations

positively charged ions; Na+, K+, Ca+, and Mg+

800 mL

min daily requirement for water - 0-≤6 mos infant

1000 mL

min daily requirement for water - 6-≤12 mos infant

Electrolytes

Used by the body to help regulate the distribution, composition, and acidity of fluids; with the help of these, cells move water by indirect meas as water follows these

Oncotic Pressure

Exerted by proteins in the plasma; eeps the fluid inside the blood

Hydrostatic Pressure

Exerted by the pumping action of the heart on the fluid in the blood vessels' keeps the fluid outside the blood vessels

Bicarbonate Buffer

Most important electrolyte buffering system

7.4

Plasma pH

7.35 - 7.45

Optimal pH at which the body can operate

- Buffer systems

- lungs, excreting Co2

- kidneys, excreting excess acids in the urine

3 Body mechanisms that maintains normal pH range