Question

Assertion: Most of the secretion of liver is pass out along with faecal matter. Reason: Bile juice is secreted in digestive tract.

Short answer

Yes, the assertion is correct and the reason is the correct explanation of the assertion. The liver's major secretion, bile, is secreted into the digestive tract, where it aids in digestion and absorption of fat before being excreted through faecal matter.

Step-by-step solution

Understanding the Assertion

The liver is the largest gland in the human body. It performs many vital functions, including the production of bile. Bile is a digestive liquid that aids in the digestion and absorption of fats. When it is said that 'Most of the secretion of liver is passed along with faecal matter', it indicates that bile (the liver's major secretion), after performing its roles, is excreted from the body through faecal matter.

Understanding the Reason

Bile, after being produced by liver cells, is concentrated and stored in the gallbladder. When ingested food enters the small intestine from the stomach, bile is secreted there. The reason correctly states that 'Bile juice is secreted in the digestive tract.' The bile aids in the digestion and absorption of fats in the small intestine.

Correlating the Assertion with the Reason

Now that the roles and journey of bile are understood, it is clear that bile, which is secreted by the liver into the digestive tract, finally gets excreted through faecal matter, which correlates with the assertion. Therefore, the reason is corroborating the assertion provided.

Key concepts

Liver Secretions

The liver is not only the body's chemical factory but also a remarkable organ for its secretory functions. One of its key roles is to produce bile, a yellowish-green liquid that plays a critical role in the digestive process. Bile is composed of substances such as bile acids, cholesterol, phospholipids, and bilirubin, which are crucial for the breakdown and absorption of fats.

Upon eating, the liver secretes bile continuously, but the flow of bile is regulated according to the body's needs, particularly during digestion. When not needed for digestion, bile is stored in the gallbladder. This intelligent system ensures that when we ingest fat-containing foods, bile is readily released into the small intestine to emulsify fats, making them more accessible to digestive enzymes. Without this secretion, the digestion of fats would be less efficient, impacting the overall digestive health.

Digestion and Absorption of Fats

Digesting fats is a complex process that requires several steps and the cooperative action of different digestive juices. Fats present in our food are large molecules that are not water-soluble, making them difficult to break down. This is where bile enters the picture.

Bile acts like a detergent, breaking down large fat globules into smaller droplets in a process called emulsification. This increases the surface area available for enzymes, mainly pancreatic lipases, to work on, leading to more efficient fat digestion. Once the fats are broken down into fatty acids and glycerol, they can be absorbed through the intestinal lining. Short-chain fatty acids, which are water-soluble, are directly absorbed into the blood, while longer-chain fatty acids are absorbed into the lymphatic system and later released into the bloodstream. This meticulous process ensures that our body can utilize the fats and oils that are consumed for energy and for building cellular components.

Excretion of Bile

Excretion of bile is a vital function for not just digestion, but also for waste removal. Bile acts as a vehicle for excreting waste products from the liver into the intestines. Among these waste products, bilirubin, which is a byproduct of the breakdown of old red blood cells, gives bile its characteristic color.

The excretion of bile also serves to eliminate excess cholesterol and other metabolic byproducts. After fulfilling its digestive duties, bile travels through the digestive system and its components are reabsorbed, metabolized, or excreted. A significant portion of bile acids is reclaimed in the ileum and returned to the liver for reuse, a process known as enterohepatic circulation. However, the components that are not reabsorbed, including bilirubin and other waste materials, continue through the intestines and are eventually eliminated with the stool, giving it its brown color.