Free CRNI Fluid and Electrolyte Balance Questions and Answers — Questions and Answers
Question 1: The body's _______ system is the main pathway for water loss.
- urinary (Correct answer)
- respiratory
- integumentary
- digestive
Correct answer: urinary
The urinary system, primarily through the kidneys, plays the most crucial role in regulating the body's water balance and expelling excess water. The kidneys filter blood, reabsorb necessary water, and excrete waste products dissolved in urine. While other systems contribute to water loss, the urinary system is the main pathway for controlled water excretion.
Question 2: The body loses ions mostly through its _______ system.
- integumentary
- respiratory
- digestive
- urinary (Correct answer)
Correct answer: urinary
The urinary system, particularly the kidneys, is the primary organ system responsible for maintaining electrolyte (ion) balance in the body. The kidneys filter blood, reabsorbing essential ions like sodium, potassium, and chloride, while excreting excess ions in the urine. This precise regulation is vital for nerve function, muscle contraction, and overall cellular homeostasis.
Question 3: In most cells, careful management of cell volume (and hence cell function)
- blood pressure.
- volume of extracellular fluid.
- permeability of cell membranes.
- osmolarity of extracellular fluid. (Correct answer)
Correct answer: osmolarity of extracellular fluid.
Cell volume is critically dependent on the osmolarity of the extracellular fluid (ECF). Water moves across cell membranes by osmosis, from an area of lower solute concentration to an area of higher solute concentration, to equalize osmolarity. If the ECF osmolarity changes, water will move into or out of cells, causing them to swell or shrink, which can impair their function.
Question 4: The majority of the body's water balance is controlled by two organ systems that interact with one another.
- urinary and cardiovascular. (Correct answer)
- cardiovascular and respiratory.
- urinary and respiratory.
- digestive and respiratory.
Correct answer: urinary and cardiovascular.
The urinary system (kidneys) and the cardiovascular system work in close conjunction to maintain the body's water balance. The kidneys regulate blood volume and composition by filtering blood and adjusting water and solute excretion, directly impacting blood pressure and overall fluid balance. The cardiovascular system, by circulating blood, delivers water and solutes to the kidneys and distributes hormones that influence kidney function, ensuring efficient fluid homeostasis.
Question 5: Which of the following is caused by shrinking hepatocytes in the liver?
- both glycogen breakdown and protein breakdown (Correct answer)
- protein synthesis only
- glycogen breakdown only
- glycogen production only
Correct answer: both glycogen breakdown and protein breakdown
Cell shrinkage, often caused by hyperosmolarity in the extracellular fluid, is a stress signal that can trigger catabolic processes within hepatocytes. When liver cells shrink, it activates pathways that lead to the breakdown of stored glycogen (glycogenolysis) to release glucose and the breakdown of proteins (proteolysis) to provide amino acids for energy or other metabolic needs. This response helps the cell adapt to osmotic stress and maintain energy supply.
Question 6: Most of the body's water is found in
- cells. (Correct answer)
- plasma.
- lumens of organs open to the outside.
- interstitial fluid.
Correct answer: cells.
The majority of the body's water is found within the intracellular fluid (ICF), which is the fluid contained inside cells. Approximately two-thirds of the total body water resides within cells, making it the largest fluid compartment. The remaining one-third is extracellular fluid, divided between interstitial fluid and plasma.
Question 7: Dehydration results in water retention in the urine bladder.
- will still be expelled from the body in the urine. (Correct answer)
- can be returned to the circulation directly.
- can be returned to the circulation after moving back into the kidneys.
- All of the above
Correct answer: will still be expelled from the body in the urine.
Even in states of dehydration, the body must still excrete metabolic waste products, which requires a minimum amount of water to dissolve them. While the kidneys will conserve as much water as possible by producing highly concentrated urine, some water will inevitably be lost in the urine to eliminate these wastes. The urine bladder serves as a temporary storage for this waste before it is expelled.
Free CRNI Fluid and Electrolyte Balance Questions and Answers
The body's _______ system is the main pathway for water loss.