Olympiad Test: Nutrition in Animals - UPSC MCQ

The stomach stores the food for 4-5 hours. The food mixes thoroughly with the acidic gastric juice of the stomach by the churning movements of its muscular wall and is called the chyme. 

The proenzyme pepsinogen, on exposure to hydrochloric acid gets converted into the active enzyme pepsin, the proteolytic enzyme of the stomach. Pepsin converts proteins into proteoses and peptones (peptides).

Roughage is a component of food which do not provides energy or help in body building. Roughage helps in movement of food in alimentary canal.

The mode of digestion which takes place inside the cell is called as intracellular digestion. Most of multicellular organism digest food inside the cell.

 Intracellular digestion takes place in animals without a digestive tract, in which food items are brought into the cell for digestion.

The mode of nutrition in amoeba is holozoic. Amoeba digests the food inside food vacuole that contain enzyme for digestion.

Liver is the largest gland in the human body. Liver secretes bile juice that contains bile salt. Emulsification of fat occurs by the action of bile salt.

Saliva is released from salivary gland present in mouth. Saliva contains salivary amylase that helps in digestion of starch.

The interior walls of the small intestine are tightly wrinkled into projections called circular folds that greatly increase their surface area. Microscopic examination of the mucosa reveals that the mucosal cells are organized into finger-like projections known as villi, which further increase the surface area.

Canines are sharp teeth used for tearing food. Canine is more prominent in carnivores to tear the meat.

The process of chewing food is called mastication. Teeth and tongue help in mastication of food.

Human alimentary canal is about 9 meter long. Small intestine forms the largest part of meet. Most of digestion takes place in small intestine.

The movement o food by regular contraction and expansion of food pipe is called peristaltic movement.

Bile is secreted from liver that contain bile salt. Bile salt helps in emulsification of fat.

Enzymes are biological catalyst that breakdown the complex food into simple form. Enzymes are released from exocrine glands.

The mucosa is a mucous membrane. It is the innermost lining of the small intestine. It is made up of a:

• the layer of epithelial cells (called the epithelium)
• a layer of loose connective tissue (called the lamina propria)
• the very thin layer of muscle (called the muscularis mucosa)

The inner surface of the mucosa has many finger-like projections called villi. The villi increase the surface area of the small intestine, which helps it absorb digested food.

Absorption of water in alimentary canal takes place in the Large intestine.
The process of absorption refers to the movement of water, nutrients, and other substances from the digestive system into the bloodstream. In the case of water absorption, it plays a crucial role in maintaining the body's fluid balance and preventing dehydration. The absorption of water in the alimentary canal specifically occurs in the large intestine.
Here is a detailed explanation of water absorption in the large intestine:
Anatomy of the Large Intestine:
- The large intestine is the final section of the digestive tract, following the small intestine.
- It is a wider and shorter tube that measures about 1.5 meters in length.
- The major parts of the large intestine include the cecum, colon, rectum, and anal canal.
Process of Water Absorption in the Large Intestine:
1. Residue from the small intestine enters the large intestine through the ileocecal valve.
2. In the large intestine, the residue passes through the ascending colon, transverse colon, descending colon, sigmoid colon, and finally reaches the rectum.
3. The large intestine mainly functions to reabsorb water and electrolytes from this residue before it is eliminated as feces.
4. The walls of the large intestine are lined with specialized cells called colonocytes that facilitate water absorption.
5. The colonocytes actively transport sodium ions out of the lumen of the large intestine and into the interstitial fluid.
6. The movement of sodium ions creates an osmotic gradient, causing water to follow passively through osmosis.
7. As a result, water is absorbed from the residue and into the bloodstream, helping to maintain the body's hydration levels.
8. The remaining residue, which is now more solid, continues to move through the large intestine and eventually reaches the rectum for elimination.

Significance of Water Absorption in the Large Intestine:
- The large intestine plays a crucial role in maintaining water balance in the body.
- It helps prevent dehydration by reabsorbing water from the residue, which would otherwise be lost as feces.
- The absorbed water is then transported to the bloodstream, where it can be distributed to various parts of the body.
- Adequate water absorption in the large intestine is essential for maintaining normal bowel movements and preventing constipation.
In conclusion, the absorption of water in the alimentary canal takes place in the large intestine. The walls of the large intestine, particularly the colonocytes, actively transport sodium ions, creating an osmotic gradient that facilitates water absorption through osmosis. This process helps maintain the body's fluid balance and prevents dehydration.

The oesophagus is also called the gullet or food pipe. It is part of the digestive system, which is sometimes called the gastro-intestinal tract (GI tract). The oesophagus is a muscular tube about 25cm (10in) long. It connects your mouth to your stomach.

ORS stands for Oral rehydration solution. It is used in case of dehydration to maintain water and salt levels in body.

Bile salts are one of the primary components of bile. Bile is a greenish-yellow fluid made by the liver and stored in our gallbladder.

The wall of stomach contains gastric glands which secretes gastric juice. Gastric juice contain pepsin, HCl and mucus.

Cellulose is a type of carbohydrate that can be digested by ruminants and not by humans. 
Ruminants have a large sac-like structure called rumen between the oesophagus and the small intestine. The cellulose of the food is digested here by the action of certain bacteria which are not present in humans.