Nursing Elites

1. Which vitamin is essential for proper absorption of calcium and plays a role in lung function?

• A. Vitamin A
• B. Vitamin B12
• C. Vitamin D
• D. Vitamin E

Correct answer: C

Rationale: The correct answer is Vitamin D. Vitamin D is crucial for the proper absorption of calcium in the intestines and is essential for maintaining lung function. It regulates calcium and phosphorus levels, crucial for healthy bones and teeth. Vitamin A is important for vision and immune function, not specifically for calcium absorption or lung function. Vitamin B12 is essential for nerve function and red blood cell production, not related to calcium absorption or lung function. Vitamin E is an antioxidant that helps protect cells from damage, but it is not directly involved in calcium absorption or lung function.

2. What is the primary function of the pyloric sphincter?

• A. to regulate the movement of food material from the stomach to the duodenum
• B. to neutralize stomach acid
• C. to prevent digested food materials and stomach acid from entering the esophagus
• D. to begin the process of chemical digestion

Correct answer: A

Rationale: The primary function of the pyloric sphincter is to regulate the flow of partially digested food material (chyme) from the stomach into the small intestine, specifically the duodenum. This control is essential for proper digestion and absorption of nutrients in the small intestine. Choices B, C, and D are incorrect. Choice B is incorrect because neutralizing stomach acid is primarily the function of the stomach lining and antacid mechanisms. Choice C is incorrect because preventing the backflow of digested food materials and stomach acid into the esophagus is mainly the role of the lower esophageal sphincter. Choice D is incorrect because the chemical digestion process primarily starts in the stomach through the action of gastric juices, not the pyloric sphincter.

3. What is the main factor limiting population growth in K-strategists?

• A. Predation
• B. Availability of resources
• C. Competition
• D. Disease

Correct answer: B

Rationale: K-strategists are species with a low reproductive rate that invest more resources in raising fewer offspring. These species typically live in stable environments with limited resources. The main factor limiting population growth in K-strategists is the availability of resources such as food, shelter, and space. When resources are scarce, K-strategists may struggle to find enough to support their population size, leading to reduced reproductive success and population growth. While predation, competition, and disease can also impact population growth, the primary limiting factor for K-strategists is the availability of resources.

4. What is the general formula for an alkene?

• A. CnH2n+2
• B. CnH2n
• C. CnH2n-2
• D. CnH2n+1

Correct answer: B

Rationale: The general formula for an alkene is \(C_nH_{2n}\), indicating the presence of a double bond between carbon atoms.

5. What controls the involuntary, rhythmic contractions of the heart muscle?

• A. Lungs
• B. Brain
• C. Spinal cord
• D. Sinoatrial node (located within the heart)

Correct answer: D

Rationale: The correct answer is D: Sinoatrial node (located within the heart). The involuntary, rhythmic contractions of the heart muscle are controlled by a specialized group of cells located within the heart called the sinoatrial node (SA node). The SA node acts as the heart's natural pacemaker, producing electrical impulses that regulate the heart rate and synchronize the contractions of the heart muscle. Choices A, B, and C (Lungs, Brain, Spinal cord) are not responsible for directly influencing the rhythmic contractions of the heart muscle.

Similar Questions