Feces is usually about 40 percent water and 60 percent solid matter. Reducing the water content to 20 percent would most likely result in

Answer Explanation

A) Mouth, Esophagus, Stomach: This option is incorrect because while saliva in the mouth does contain digestive enzymes (such as amylase for breaking down carbohydrates), the esophagus is not a site of enzyme secretion. The stomach secretes gastric juices which primarily contain hydrochloric acid and pepsinogen (which is converted to pepsin, a protein-digesting enzyme), but the esophagus itself does not secrete digestive enzymes.

B) Stomach, Small Intestine, Large Intestine: This option is incorrect because while both the small intestine and the large intestine play crucial roles in digestion and absorption, enzyme secretion mainly occurs in the stomach and small intestine. The large intestine primarily absorbs water and salts and does not secrete digestive enzymes.

C) Mouth, Stomach, Small Intestine: This option is correct. Enzymes are secreted in the mouth (amylase), stomach (pepsin for protein digestion), and small intestine (various enzymes including pancreatic enzymes like lipase, protease, and amylase, as well as enzymes produced by the intestinal lining).

D) Esophagus, Stomach, Large Intestine: This option is incorrect because while the stomach does secrete digestive enzymes, the esophagus and large intestine do not. The large intestine primarily absorbs water and salts and does not secrete digestive enzymes.

Answer Explanation

D) pancreas

- Correct: After food enters the small intestine, lipases (for fat digestion), proteases (for protein digestion), and amylases (for carbohydrate digestion) are secreted into the small intestine by the pancreas. These digestive enzymes are produced by the pancreas and released into the duodenum, which is the first part of the small intestine. The pancreas plays a crucial role in providing these enzymes to aid in the breakdown of macronutrients (fats, proteins, and carbohydrates) into smaller molecules that can be absorbed by the intestinal lining.

A) liver

- Incorrect: The liver produces bile, which is stored in the gallbladder and released into the small intestine to aid in the emulsification of fats. While bile is important for fat digestion, it does not contain lipases, proteases, or amylases.

B) gallbladder

- Incorrect: The gallbladder stores and concentrates bile produced by the liver, but it does not secrete lipases, proteases, or amylases. Bile aids in the emulsification of fats but does not contain digestive enzymes.

C) salivary glands

- Incorrect: Salivary glands secrete saliva into the mouth, which contains amylase, an enzyme that begins the digestion of carbohydrates. However, after food enters the small intestine, digestive enzymes are primarily secreted by the pancreas, not the salivary glands.

Answer Explanation

B) gall bladder

- Correct: Bile, which aids in the emulsification of fats in the small intestine, is stored and concentrated in the gall bladder before being released into the small intestine. When fatty foods enter the small intestine, the gall bladder contracts and releases bile into the duodenum (the first part of the small intestine). Bile helps to break down large fat globules into smaller droplets, a process known as emulsification, which increases the surface area for the action of digestive enzymes, such as lipase, facilitating the digestion and absorption of fats.

A) stomach

- Incorrect: Bile is not released from the stomach. The stomach primarily secretes gastric juices containing hydrochloric acid and pepsinogen to aid in the digestion of proteins.

C) villi

- Incorrect: Villi are finger-like projections in the lining of the small intestine that increase its surface area for nutrient absorption but do not release bile.

D) lacteals

- Incorrect: Lacteals are lymphatic vessels found in the villi of the small intestine that absorb dietary fats and fat-soluble vitamins. They do not release bile.