Introduction:
The liver plays a critical role in the metabolic activity of the body. It regulates nutrients, carbohydrates, protein, and fat metabolism in a simpler form so that the body can absorb them to generate energy and build cells and tissues.
What Is the Liver?
The liver is considered the largest internal organ in humans. It has many functions like bile production and excretion, removing toxic wastes from the body, metabolizing proteins, fats, and carbohydrates, enzyme activation, and plasma protein synthesis. If there is liver disease, the above functions will not be carried out by the liver normally.
What Is Carbohydrate Metabolism in the Liver?
The liver has a crucial role in sustaining blood glucose (sugar) levels. The liver absorbs sugars from the food ingested and is circulated in the blood. The sugars are broken down to generate energy for various functions in the body, and this process is called glycolysis. The extra sugar molecules that do not take part in the energy-generating process are transformed into glycogen (a class of sugar that is saved in the liver), and the process is called glycogenesis. The liver stores the glycogen and is used for later use when there is a glucose demand.
The body, during starvation or energy demand after heavy work, requires energy. The liver, at this stage, converts the stored glycogen into glucose and releases it into blood circulation to meet the demand. This process is called glycogenolysis. The liver also gets glucose from amino acids, which are not sugar, by a process called gluconeogenesis.
During liver damage or dysfunction, the blood glucose levels will be altered. The reduced amounts of glucose in the blood results in decreased energy supply to the brain and muscles, resulting in weakness, fatigue, and slow thinking.
How Are Fats Metabolized in the Liver?
The food we eat consists of certain amounts of fat. The body uses this fat to generate energy and to make hormones. The liver plays a vital role in fat metabolization, and it produces lipoproteins, cholesterol, and phospholipids. Lipoprotein is a type of protein that carries fats to be circulated in the blood since fat is not soluble both in blood and water.
Cholesterol is a waxy type of fat present in body cells. They play an essential role in manufacturing bile salt, sex hormones, vitamin D, and other hormones for the immune system. Cholesterol is also crucial in maintaining healthy nerve cells and the brain. Phospholipids are a type of lipid and are an essential component in a cell wall. It contributes to cell membrane flexibility and stiffness.
The liver stores when there is excess fat. They are also stored in subcutaneous tissue (below the skin) and other storage areas like the abdominal region (stomach area). This process of converting excess fat (fatty acids and glycerol) to storage form is called lipogenesis. This method of energy generation from fat is an alternative to energy derived from sugars. When there is low energy or low glucose levels, the stored fats are converted back to glycerol and fatty acids for energy generation. This process is called lipolysis.
How Are Proteins Metabolized in the Liver?
The amino acids are clubbed together to form proteins. The amino acids are absorbed from the food ingested, and it processes proteins. These amino acids are also converted into fat or carbohydrates and are stored in the liver. These altered fats are processed and transformed into energy when there is an energy shortage. During this process, a harmful substance called ammonia results as an outcome. The liver acts quickly and converts the toxic ammonia to urea, which is excreted in the urine.
How Are Hormones Metabolized in the Liver?
The liver plays a very important role in hormone metabolization. Hormones are chemical messengers responsible for some processes like menstruation or the appearance of acne, and they control these processes. They convert the hormones into their active forms. The liver breaks down the extra hormones present and removes them from the body. The hormones metabolized in the liver are sex hormones (hormones that are responsible for sexual drive), thyroid hormones (a hormone that regulates the energy rate), and steroid hormones (hormones that control immune mechanisms and control body metabolism).
How Are Red Blood Cells Metabolized in the Liver?
The red blood cells are metabolized in the liver. Red blood cells are components of blood. It has a protein called hemoglobin. Hemoglobin carries oxygen to all the tissue in the body. The lifespan of a red blood cell is 120 days. First, the red blood cells disintegrate into heme (iron) and globin (protein). The heme further metabolizes to biliverdin, a green pigment. This further reduces to bilirubin, a yellowish stain fluid, and is excreted into bile (a liquid produced by the liver that helps in digestion) which undergoes a few processes and is discharged through stools.
How Are Toxins Metabolized in the Liver?
The liver metabolizes the medications and alcohol consumed. The liver processes them and converts them to a readily absorbable form. The byproducts of this process are toxic substances. The liver contains sinusoids (an irregular tube-like pathway for blood flow) which are lined by Kupffer cells. The Kupffer cells are phagocytic cells (immune cells that play an important role in immune response) that line the sinusoids and engage in defending against infections. These Kupffer cells swallow the toxins, digest them, and remove them from the body.
What Will Happen if the Metabolic Activity of the Liver Are Compromised?
The metabolic activity of the liver is affected when there is liver disease. It will result in the accumulation of unmetabolized hormones, toxic wastes, and ammonia which will further damage the liver.
Conclusion:
The liver is a vital organ and performs various functions paramount for normal body function. The metabolic activity of the liver is important as it processes and removes toxic substances from the body. The metabolic activity of the liver will be unaffected if proper diet and healthy lifestyle modifications are followed. However, these metabolic activities are affected if there is liver disease or liver damage. A group of blood tests can find them called liver function tests. This enables an individual to rule out the disease and get appropriate treatment to avoid complications.
