Electrolytes and Body Fluids — Flashcards

Flashcard 51: Among osmolarity and osmolality, which one is affected by the volume of the various solutes in the solution and the temperature?_____

Answer: Osmolarity

Flashcard 52: The volume of a fluid compartment in the body can be measured by _____ method.

Answer: "indicator (dye)-dilution"

Flashcard 53: Nasal secretions have a pH of about _____

Answer: 5.5 – 6.5 (slightly acidic)

Flashcard 54: Interstitial fluid pressure is positive in rigid closed compartments- _____

Answer: bone marrow, brain (2)

Flashcard 55: The volume of sweat normally is about _____/day,

Answer: 100 ml

Flashcard 56: Interstitial fluid pressure is positive in encapsulated organs- _____

Answer: kidney, skeletal muscle (2)

Flashcard 57: The total safety factor against edema is about _____ mmHg.

Answer: 17

Flashcard 58: Which fluid compartment has a higher **percentage** of body weight in infants than in adults, but a smaller **absolute volume**?

Answer: ECF (Extracellular Fluid)

Extra: In infants, ECF constitutes about 40% of body weight, whereas in adults it is about 20%. Despite this higher percentage, the absolute volume (in liters) of ECF is much smaller in infants due to their smaller total body mass. Note: ICF percentage is lower in infants (~35%) than in adults (~40%).

Flashcard 59: The value of normal tissue oncotic pressure is _____ mmHg

Answer: 8

Extra: According to Guyton and Hall Textbook of Medical Physiology, the average interstitial (tissue) colloid osmotic (oncotic) pressure is approximately **8 mmHg**. **Starling Forces Summary (Systemic):** * **Capillary Hydrostatic Pressure ($P_c$):** ~17.3 mmHg (mean) * **Interstitial Hydrostatic Pressure ($P_{if}$):** -3 mmHg * **Plasma Colloid Osmotic Pressure ($\pi_p$):** 28 mmHg * **Interstitial Colloid Osmotic Pressure ($\pi_{if}$):** 8 mmHg Net filtration pressure is approximately 0.3 mmHg, which is returned to circulation via the lymphatics.

Flashcard 60: The normal insensible water loss is _____ mL/hour.

Answer: 50