Nokea
Where does the absorption of most nutrients occur?
- A. Large intestine.
- B. Small intestine.
- C. Stomach.
- D. Mouth.
Correct Answer: B
Rationale: The absorption of most nutrients occurs in the small intestine. This is where digested food is broken down further and absorbed into the bloodstream through the intestinal walls. The large intestine primarily absorbs water and electrolytes, while the stomach mainly aids in digestion by breaking down food with gastric juices. The mouth is responsible for the initial mechanical breakdown of food through chewing and the enzymatic action of saliva, but absorption does not occur there.
You may also like to solve these questions
After ingested food is mixed and churned with gastric secretions, the resulting semifluid mass is called:
- A. a bolus.
- B. chyme.
- C. rennin.
- D. glycogen.
Correct Answer: B
Rationale: The correct answer is B: chyme. Chyme is the partially digested food that forms a semifluid mass after mixing with gastric juices. A is incorrect because a bolus refers to a rounded mass of food ready to be swallowed. C, rennin, is an enzyme involved in the digestion of milk proteins and not the term for the semifluid mass after food mixing with gastric secretions. D, glycogen, is a form of stored glucose in the body and is not the term used to describe the partially digested food mass in the stomach.
What substance acts as an emulsifier and helps absorb digested fat?
- A. bile
- B. trypsin
- C. lipase
- D. cholecystokinin (CCK)
Correct Answer: A
Rationale: The correct answer is A: bile. Bile acts as an emulsifier, breaking down fats into smaller droplets to aid in digestion and absorption. Trypsin is a digestive enzyme that acts on proteins, not fats. Lipase is an enzyme that breaks down fats, but it doesn't act as an emulsifier. Cholecystokinin (CCK) is a hormone that stimulates the release of digestive enzymes, including lipase, but it is not directly involved in emulsification.
The interrelated network of nerves within the gastrointestinal wall that regulates its muscular action is known as the:
- A. gastric nerve plexus.
- B. biliary nerve plexus.
- C. intramural nerve plexus.
- D. intestinal nerve plexus.
Correct Answer: C
Rationale: The correct answer is C - intramural nerve plexus. This network of nerves regulates the muscular movements within the gastrointestinal wall. The gastric nerve plexus (choice A) specifically relates to the stomach, not the entire gastrointestinal tract. The biliary nerve plexus (choice B) is associated with the bile ducts and gallbladder, not the regulation of muscular action. The intestinal nerve plexus (choice D) is a general term that doesn't specifically refer to the network of nerves within the gastrointestinal wall.
Ketones are produced when:
- A. carbohydrate stores are depleted.
- B. excess protein is consumed.
- C. protein stores are depleted.
- D. fat stores are depleted.
Correct Answer: A
Rationale: Ketones are produced when the body uses fat for energy due to the depletion of carbohydrate stores. When carbohydrate stores are depleted, the body turns to fat as its primary source of energy, leading to the production of ketones. Excess protein consumption does not directly lead to ketone production. Similarly, the depletion of protein stores or fat stores is not directly related to the production of ketones.
The valve that controls the passage of chyme from the small intestine into the cecum is called the:
- A. ileocecal valve.
- B. pyloric valve.
- C. cardiac valve.
- D. hepatic valve.
Correct Answer: A
Rationale: The correct answer is A: ileocecal valve. The ileocecal valve is located between the small intestine and the cecum, controlling the passage of chyme. The pyloric valve (choice B) is located between the stomach and the small intestine, regulating the passage of food from the stomach to the small intestine. The cardiac valve (choice C) refers to the valve between the esophagus and the stomach. The hepatic valve (choice D) is not a correct term related to the passage of chyme from the small intestine into the cecum.