All of the following are organs of the digestive system except

Answer Explanation

C) They change food substances into molecules that can pass into the bloodstream and cells.

- Correct: Digestive enzymes secreted by the pancreas play a crucial role in breaking down complex food molecules into smaller, absorbable molecules that can pass through the walls of the small intestine and into the bloodstream. These smaller molecules include carbohydrates broken down into simple sugars, proteins broken down into amino acids, and fats broken down into fatty acids and glycerol. Once these molecules are absorbed into the bloodstream, they can be transported to cells throughout the body to provide energy and support various metabolic processes.

A) They form proteins needed in the stomach.

- Incorrect: Digestive enzymes do not form proteins needed in the stomach. Proteins are broken down into amino acids by digestive enzymes, but the enzymes themselves do not form proteins.

B) They form the acids that break down food.

- Incorrect: Digestive enzymes do not form acids. Acids such as hydrochloric acid are secreted by the stomach and aid in the breakdown of food, particularly proteins, but they are not formed by pancreatic enzymes.

D) They change food materials into wastes that can be passed out of the body.

- Incorrect: While digestive enzymes help break down food materials, their primary function is to convert these materials into absorbable molecules rather than wastes. The conversion of food into waste products occurs primarily through processes in the digestive tract and is facilitated by enzymes as part of digestion, but it is not the direct role of pancreatic enzymes.

Answer Explanation

A) liver and pancreas

- Correct: The liver and pancreas both secrete chemicals that are utilized for the completion of digestion within the small intestine. The liver produces bile, which is stored in the gallbladder and released into the small intestine to aid in the emulsification and digestion of fats. The pancreas secretes pancreatic enzymes (such as amylase, lipase, and proteases) into the small intestine to further break down carbohydrates, fats, and proteins into smaller molecules that can be absorbed.

B) glomerulus and villi

- Incorrect: The glomerulus is a part of the kidney involved in the filtration of blood, and villi are finger-like projections in the small intestine that increase surface area for absorption. While villi play a role in absorption within the small intestine, they do not secrete chemicals for digestion. The glomerulus is not involved in digestion.

C) esophagus and alveoli

- Incorrect: The esophagus is involved in swallowing and does not secrete chemicals for digestion. Alveoli are air sacs in the lungs where gas exchange occurs during respiration and are not involved in digestion.

D) gallbladder and pharynx

- Incorrect: The gallbladder stores bile produced by the liver but does not secrete chemicals directly into the small intestine. The pharynx is involved in swallowing and does not secrete chemicals for digestion.

Answer Explanation

The digestive system provides materials in the form of nutrients from food, such as carbohydrates, fats, and proteins. These nutrients are broken down during digestion and absorbed into the bloodstream.

The respiratory system provides oxygen, which is necessary for cellular respiration, the process by which ATP (adenosine triphosphate) is produced in cells. Oxygen is inhaled into the lungs and diffuses into the bloodstream to be transported to cells throughout the body.