Food And Digestive System For Class 4

Explanation
Digestion is the correct answer because it refers to the process of breaking down food into smaller molecules that can be absorbed and utilized by the body. Combustion is the process of burning, not relevant to food breakdown. Mixing refers to the combining of ingredients, not specifically related to food breakdown. Ingestion refers to the intake of food, but does not encompass the process of breaking it down.

Explanation
Digestion starts in the mouth. This is where the process of breaking down food begins. The mouth contains teeth that mechanically break down food into smaller pieces, and saliva is produced to moisten the food and begin the chemical breakdown of carbohydrates. After chewing and mixing the food with saliva, it is then swallowed and travels down the esophagus into the stomach, where further digestion occurs. Therefore, the mouth is the correct answer as it is the initial site of digestion.

Explanation
When food enters the mouth, it is chewed and mixed with saliva to form a soft, rounded mass called a bolus. The bolus is then swallowed and moves down the esophagus into the stomach. Therefore, the correct answer is bolus.

Explanation
Bile is a digestive fluid that helps in the breakdown and absorption of fats. It is produced by the liver and stored in the gallbladder. When we consume fatty foods, the gallbladder releases bile into the small intestine to aid in digestion. The liver is responsible for the production of bile, making it the correct answer in this case.

Explanation
Carbohydrates are broken down in the mouth through the process of chewing and mixing with saliva. Saliva contains an enzyme called amylase, which begins the breakdown of carbohydrates into simpler sugars. This initial digestion in the mouth prepares the carbohydrates for further breakdown and absorption in the small intestine. Therefore, the correct answer is "Mouth".

Explanation
Villi are finger-like projections in the small intestine that increase the surface area for absorption of nutrients. They are covered in microvilli, which further increase the surface area. The villi contain blood vessels and lacteals, which help in the absorption of nutrients into the bloodstream. This structure allows for efficient absorption of nutrients from digested food, making villi an essential feature of the small intestine.

Explanation
The parotid glands are the largest salivary glands in the human body. They are located near the ears, in front of the earlobes. These glands produce saliva, which helps in the digestion process by moistening food and breaking it down. The parotid glands secrete saliva into the mouth through a duct called Stensen's duct. These glands are responsible for producing the majority of the saliva in the mouth.

Explanation
The small intestine is approximately 25 feet long.

Explanation
The correct answer is 2-4 hours. After we eat, the food enters the stomach where it is broken down by stomach acid and digestive enzymes. This process usually takes about 2-4 hours. After this, the partially digested food moves into the small intestine for further digestion and absorption of nutrients. Therefore, food stays in the stomach for approximately 2-4 hours before it continues its journey through the digestive system.

Explanation
The waste produced during the digestion process is stored in the rectum before it is expelled from the body. The rectum is the final section of the large intestine where feces are accumulated and held until they are ready to be eliminated through the anus.