47 - The Liver (w/ Nyssa Tucker!)
47. The Liver
The liver is an organ that is mostly indispensable for life as animals know it. What are organs? Why do we need them? What is the liver? Let’s learn to be scientifically conversational.
General Learning Concepts
1) What is an organ?
a. Homeostasis: The term was coined in 1930 by the physician Walter Cannon. Homeostasis, from the Greek words for "same" and "steady," refers to any process that living things use to actively maintain fairly stable conditions necessary for survival.
b. Tissue: Related cells joined together; while not identical, they often accomplish similar specific functions.
c. Organs: Recognizable structures that perform a specific function. Often made up of multiple types of tissues.
2) What is the Liver?
a. General overview: One of the largest organs in the body. Converts nutrients from dietary intake into usable metabolites, stores energy, and can uptake toxic substances. It is found in the upper right abdomen, taking up most of the space under the ribs. The gallbladder is found in a small hollow on the underside of the liver.
b. Lobules: Structural units of liver cells.
c. Metabolism: The liver is critical for fat metabolism. To break down fats, liver cells produce bile carried by the main bile duct to the small intestine. With carbohydrates, the liver ensures the consistency of blood glucose levels by modulating glycogen levels. With proteins, the liver break down amino acids and reduce levels of ammonia by converting it to the less toxic substance urea. The liver also plays a role in breaking down old / damaged blood cells.
4) Fun Tidbits
a. Organelles: any of a number of organized or specialized structures within a living cell. The structures are a part of cells, similarly to how organs are part of the whole body. Credited as the first to use a diminutive of organ for respective cellular structures was German zoologist Karl August Möbius (1884), who used the term "organula".
b. Weight: An average liver weighs about 3 pounds.
5) Solicited Questions
a. How does alcohol metabolism work? Once swallowed, a drink enters the stomach and small intestine, where small blood vessels carry it to the bloodstream. Approximately 20% of alcohol is absorbed through the stomach and most of the remaining 80% is absorbed through the small intestine. Alcohol is metabolized by the liver, where enzymes break down the alcohol. Understanding the rate of metabolism is critical to understanding the effects of alcohol. In general, the liver can process one ounce of liquor (or one standard drink) in one hour. If you consume more than this, your system becomes saturated, and the additional alcohol will accumulate in the blood and body tissues until it can be metabolized. [2]