CH 24A: Fluid Balance

3 types of homeostatic balance

• Fluid Balance

• Electrolyte Balance

• Acid-Base Balance

Homeostasis is maintained by

The collective action of urinary, respiratory, digestive, integumentary, endocrine, nervous, cardiovascular, and lymphatic system

Total body water volume

60% of body weight; v= 40L

• ICF + ECF + IF + Plasma

Intercellular Fluid (ICF)

v= 25L; 40% of body weight

Extracellular Fluid (ECF)

v=15L; 20% of body weight

Interstitial Fluid (IF)

v= 12L; 80% of ECF

• apart of ECF

Plasma

V= 3L; 20% of ECF

• apart of ECF

Why is sodium high in ECF and potassium high in ICF ?

RMP

Why is calcium non existent in ICF?

calcium is bound up inside the cell, mainly in rough ER

Why is chlorine high in ECF?

chlorine likes to hang out with sodium

Why is phosphate high in ICF?

Makes DNA, phospholipids, and ATP

Water Balance requires

that intake matches output

Water intake source

Primarily from drinking water, but also food and metabolic water

Water intake loss source

MAINLY Urine, but also feces, expired air, cutaneous transpiration, and sweat

Short term signal for fixing dehydration

• Mouth cool and moist from water

• Stomach distends

NEGATIVE FEEDBACK

Alcohol

Inhibits ADH

Caffeine

Inhibits aldosterone

Water Balance Disorders

• Dehydration

• Overhydration

Hypertonic Dehydration

• Negative water balance

• Loss of water

• Requires ADH to fix

• caused by profuse sweating

Isotonic Dehydration

Loss of water AND solutes

• hypovolemia

• Aldosterone to fix

Overhydration

Hypotonic hydration: excess water normal sodium

• edema