what is the primary source of energy for the brain and nervous system

HESI LPN

LPN Nutrition Practice Test

1. What is the primary source of energy for the brain and nervous system?

A. Protein
B. Fat
C. Carbohydrate
D. Glucose

Correct answer: D

Rationale: Glucose is the correct answer as it is the primary source of energy for the brain and nervous system. The brain relies heavily on glucose to function optimally. While protein and fat play essential roles in the body, they are not the primary sources of energy for the brain and nervous system. Carbohydrates, on the other hand, are broken down into glucose, which is then used as fuel by the brain and nervous system.

2. What is a common sign of congenital hip dysplasia in infants?

A. Symmetrical hip movement
B. Limited range of motion in the hip
C. Swelling of the knees
D. Dislocated patella

Correct answer: B

Rationale: Limited range of motion in the hip, often noted as a limitation in abduction, is a common sign of congenital hip dysplasia. This limitation is due to the abnormal development of the hip joint, affecting its movement. Symmetrical hip movement (Choice A) is not a characteristic sign of congenital hip dysplasia. Swelling of the knees (Choice C) is not typically associated with this condition. Dislocated patella (Choice D) refers to a different anatomical structure and is not a common sign of congenital hip dysplasia.

3. When an increase in exercise is accompanied by a decrease in body weight, it is an example of what?

A. variable effect
B. positive correlation
C. negative correlation
D. randomization effect

Correct answer: C

Rationale: When an increase in exercise is accompanied by a decrease in body weight, it demonstrates a negative correlation. This means that as one variable (exercise) increases, the other variable (body weight) decreases. Choice A, 'variable effect,' is vague and does not accurately describe the relationship between exercise and body weight. Choice B, 'positive correlation,' is incorrect because in a positive correlation, both variables would increase or decrease together. Choice D, 'randomization effect,' is unrelated to the scenario described.

4. How does a double-blind experiment work?

A. Both subject groups take turns receiving each treatment.
B. Neither subjects nor researchers know which subjects are in the control or experimental group.
C. Neither group of subjects knows whether they are in the control or experimental group, but the researchers do not know.
D. Both subject groups know whether they are in the control or experimental group, but the researchers do not know.

Correct answer: B

Rationale: The correct answer is B. In a double-blind experiment, neither the subjects nor the researchers know which subjects are in the control or experimental group. This helps to eliminate bias and ensure that the results are more objective. Choice A is incorrect as in a double-blind experiment, subjects do not take turns receiving each treatment; it is about masking the treatment allocation. Choice C is incorrect because it implies that the researchers are aware of the group allocation, which goes against the principle of blinding in a double-blind study. Choice D is incorrect as both subject groups should not know whether they are in the control or experimental group to maintain the blindness of the study.

5. What should be included in the medical management of a sickle cell crisis?

A. Information for parents on home care
B. Adequate hydration and pain management
C. Pain management and iron supplements
D. Adequate oxygenation and factor VIII

Correct answer: B

Rationale: The correct answer is B: Adequate hydration and pain management. During a sickle cell crisis, it is essential to provide hydration to prevent vaso-occlusive events and manage pain effectively with analgesics. Adequate hydration helps maintain blood flow and prevent further sickling of red blood cells. Pain management is crucial to alleviate the severe pain associated with sickle cell crises. Options A, C, and D are incorrect. Providing information for parents on home care (Option A) may be important for ongoing management but is not specific to an acute crisis. Iron supplements (Option C) are not typically indicated during a sickle cell crisis. Adequate oxygenation and factor VIII (Option D) are not primary interventions for managing a sickle cell crisis; instead, oxygen therapy may be considered in severe cases, and factor VIII is not a standard treatment for sickle cell disease.