Lecture 1.1: Introduction to the Urinary System Flashcards
What are the Functions of the Kidney? (7)
- Water Balance
- Acid-Base Balance
- Blood Pressure
- Waste Disposal
- Blood Production (erythropoietin production)
- Activates Vit D for Bone production
- Maintains electrolyte balance
What percentage of the body is water?
- Total Body Water is approx. 60%
* Rest of the body is solids 40%
How is Total Body Water Split? And what percentages?
Extracellular Fluid (ECF): 33.3% (1/3) Intracellular Fluid (ICF): 66.6% (2/3)
What 2 parts is Extracellular Fluid split into?
Plasma: 25% (contains albumin) Interstitial Fluid (ISF): 75% (does not contain albumin)
What is Osmotic Concentration?
The total concentration of substances that do not cross the membrane freely
What is Osmolarity?
Number of osmoles (Osm) per litre (Osm/L)
What is 1 Osm?
1 mol (Avogadro’s number) of any non-dissociable substance
What is the normal osmolarity of ECF and ICF?
Approx. 287 mOsm/L
ECF and ICF need to have the same osmolarity, i.e.
they need to be…?
Isotonic
What regulates ECF volume?
Na+ ions
Where are the Kidneys located?
- Located at T11/T12-L3
* Left is superior to right due to size of liver
Why are Kidneys “Retroperitoneal” organs?
The kidneys are considered “retroperitoneal” organs, which means they sit behind a lining in the abdominal cavity, unlike all other abdominal organs
How many litres of plasma will be filtered per day?
Approx. 180 Litres
What percentage of filtered glucose and amino acids are reabsorbed?
100%
What percentage of HCO3- is reabsorbed?
100%
