Overview of Renal Physiology Flashcards
The main role of the kidney is _______
Kidneys maintain the composition and volume of extracellular fluid (Extracellular fluid homeostasis)
How do you approximate the total body fluid based on a person’s weight?
Total body fluid = 60% of body weight in kg. E.g. A 70 kg person has 42 L of total body fluid (0.6)70 = 42
What proportion of the total body fluid is intracellular fluid? how about extracellular fluid?
Intracellular fluid = 2/3 of the total body fluid Extracellular fluid = 1/3 of the total body fluid
What is intracellular fluid?
Intracellular fluid is the volume of all of the cells in the body. It contains fluid as well as other substances (e.g. electrolytes, proteins, etc)
Approximately how many cells are in an average body?
100 trillion
True or False: The concentration of intracellular fluid is similar from cell to cell and even across species
True
True or False: Intracellular Fluid is considered to be one compartment
True
What is extracellular fluid?
Extracellular fluid is the supportive environment for the cells and cellular processes that is made up of fluid and other substances( e.g. electrolytes, etc).
Extracellular fluid is made up of _____ and ____
plasma, interstitial fluid
What is plasma?
It is the non-cellular part of blood
What is interstitial fluid?
The fluid that occupies the space between cells
True or False: Plasma and interstitial fluid are constantly mixing and have the same concentration.
True
_____ and _____ interact across the capillary membrane. _____ and _____ interact across the cell membrane.
Plasma, interstitial fluid Interstitial fluid, intracellular fluid
All fluid intake and output (kidneys, lungs, feces, sweat, and skin) are directly from what fluid compartment? A. plasma B. Interstitial fluid C. Intracellular fluid
A. plasma
What are the main components of extracellular fluid? (4)
- Sodium 2. Chloride 3. Bicarbonate 4. Calcium
What are the main components of intracellular fluid? (4)
- Potassium 2. Phosphate 3. Magnesium 4. Proteins
True or False: Extracellular fluid has an optimal composition to sustain cellular processes.
True
Explain Water Balance
Water balance is part of the homeostasis that the kidneys try to achieve when managing the extracellular fluid.
Here is the example used in class:
What are the 2 input components of water balance? Which one has the highest volume?
1. Ingestion of fluids and food
- Metabolic processes
What are the 3 output components of water balance? Which one has the highest volume?
- Sweat and feces
- Insensible losses (respiration, skin, etc)
3. Urine
For regulated substances, ingestion is ______ of insensible losses
in excess
Maintenance of ECF is achieved by regulating _____
urinary output