Problem 35 - Objective Biology for NEET

Question

Large intestine consists of (a) Caecum (b) Colon (c) Rectum (d) All of these

Step-by-Step Solution

Answer

(d) All of these

Step 1: Understand the components of the large intestine

The large intestine is the last part of the digestive system. It consists of three main parts: the caecum, the colon, and the rectum.

Step 2: Evaluate each option

Option (a), (b) and (c) all are components of the large intestine. Therefore, all of these are part of large intestine.

Step 3: Select the correct answer

Since all of the options provided are parts of the large intestine, (d) All of these is the correct answer.

Key Concepts

Digestive System Components

The digestive system is a complex network that breaks down food into smaller, absorbable components. It consists of several major organs that work together in harmony. These key components include the mouth for initial digestion, the esophagus that transports food, the stomach for further breakdown, the small intestine for nutrient absorption, and finally, the large intestine. The large intestine, located in the abdomen, is crucial for water absorption and preparing waste for elimination. It encompasses three main segments, which we'll explore further. Each has unique functions that contribute to maintaining homeostasis and overall health.

Caecum Function

The caecum is the first section of the large intestine, connecting the small intestine to the colon. Its pouch-like structure serves as a transition space for digested food. Here are the primary functions of the caecum:

• Acts as a fermentation chamber in herbivores, where cellulose is broken down.
• Assists in absorbing fluids and salts that remain after intestinal digestion.
• Begins the compaction process, helping form solid waste.

By managing these initial tasks, the caecum plays a significant role in the efficient functioning of the large intestine.

Colon Function

The colon is the largest part of the large intestine, spanning from the caecum to the rectum. Structurally, it is divided into four sections: ascending, transverse, descending, and sigmoid. Each section aids in processing and transporting waste. The colon primarily:

• Absorbs water and electrolytes, preventing dehydration.
• Contains a rich microbiota that helps in breaking down remaining nutrients.
• Produces mucus to facilitate smooth movement of waste material.
• Forms and stores fecal matter before expulsion.

Through these functions, the colon significantly contributes to the overall digestive health and waste management.

Rectum Function

The rectum is the final segment of the large intestine, leading to the anus. It acts as a storage site for fecal material until defecation occurs. Here’s how the rectum functions:

• Stores feces temporarily, regulating bowel movements.
• Receives signals from the brain when it’s time to excrete waste.
• Works with sphincter muscles to control the expulsion of fecal matter.

The rectal structure and nerve responsiveness play a crucial role in maintaining continence and coordinating the final stages of digestion.