Liver

The liver is the largest internal organ of the body and a vital metabolic center. Located in the upper right abdomen, the liver has hundreds of functions - it processes nutrients absorbed from the digestive tract, detoxifies chemicals and drugs, produces bile for fat digestion, synthesizes important proteins (like albumin and clotting factors), and stores energy in the form of glycogen.

• One of the liver's key roles is filtering blood coming from the digestive organs via the hepatic portal vein. This "first pass" metabolism means nutrients and toxins absorbed in the gut are processed by the liver before entering general circulation.
• The liver produces bile, a substance that helps emulsify fats for digestion. Bile is made in the liver and stored in the gallbladder - a common test point is that the gallbladder stores bile but does not produce it.
• The liver has significant regenerative capacity - it can recover from injury by regenerating tissue. However, chronic damage (as from hepatitis or alcohol abuse) can lead to cirrhosis (scarring) which impairs liver function.

• Commonly appears in context of metabolism or detoxification. For example, a question might ask which organ is primarily responsible for converting ammonia (from protein breakdown) into urea - the answer is the liver (urea cycle). The kidneys then excrete the urea.
• Expect questions about the consequences of liver failure: e.g., easy bruising/bleeding due to lack of clotting factors, edema due to low albumin, or toxin accumulation. Knowing the liver makes clotting proteins and albumin helps connect these symptoms to liver dysfunction.
• Be mindful of confusion with the kidney: both filter blood, but the liver chemically detoxifies and metabolizes substances (drugs, alcohol, etc.), whereas the kidneys physically filter and excrete waste into urine.