how might vitamin d deficiency present

HESI A2

Anatomy HESI A2

1. How might vitamin D deficiency present?

A. As bleeding gums
B. As swollen extremities
C. As red patches
D. As crooked bones

Correct answer: D

Rationale: Vitamin D deficiency can present as crooked bones in children due to a condition called rickets. This is because vitamin D plays a crucial role in calcium absorption and bone health. Inadequate levels of vitamin D can lead to soft and weak bones, resulting in skeletal deformities such as bow legs or knock knees. Choices A, B, and C are incorrect as bleeding gums are more commonly associated with vitamin C deficiency (scurvy), swollen extremities could be a sign of various conditions like edema, and red patches are not typically a direct manifestation of vitamin D deficiency.

2. What is the primary function of the liver in the digestive system?

A. To produce bile
B. To secrete digestive enzymes
C. To store glucose
D. To store bile

Correct answer: A

Rationale: The correct answer is A: 'To produce bile.' The liver's primary role in the digestive system is to produce bile. Bile is essential for emulsifying fats, aiding in their digestion and absorption in the small intestine. Choice B is incorrect because while the liver does secrete some digestive enzymes, its primary function is bile production. Choice C is incorrect because while the liver does store glucose, it is not its primary function in the digestive system. Choice D is incorrect because the liver produces bile, but it does not store it.

3. Which structure in the ear is responsible for hearing?

A. Cochlea
B. Semicircular canals
C. Ossicles
D. Eustachian tube

Correct answer: A

Rationale: The cochlea, located in the inner ear, is responsible for detecting sound waves and converting them into neural signals that are sent to the brain for processing. It plays a crucial role in the process of hearing by translating mechanical vibrations into electrical signals that the brain can interpret as sound. The semicircular canals (Choice B) are responsible for balance and detecting head movements, not hearing. The ossicles (Choice C) are three tiny bones in the middle ear that transmit sound vibrations from the eardrum to the cochlea. The Eustachian tube (Choice D) helps equalize pressure between the middle ear and the atmosphere, but it is not directly involved in the process of hearing.

4. What is the role of the mitochondria in the cell?

A. Protein synthesis
B. Energy production
C. Breaking down waste
D. Cell division

Correct answer: B

Rationale: The correct answer is B: Energy production. Mitochondria are known as the powerhouses of the cell because they generate adenosine triphosphate (ATP) through the process of cellular respiration. ATP is a molecule that stores and releases energy, providing the cell with the necessary energy for various activities and functions. Choices A, C, and D are incorrect. Protein synthesis primarily occurs in the ribosomes, breaking down waste is mainly carried out by lysosomes, and cell division is orchestrated by the nucleus and other organelles like the centrioles.

5. Which hormone is responsible for regulating the sleep-wake cycle?

A. Melatonin
B. Thyroxine
C. Insulin
D. Cortisol

Correct answer: A

Rationale: Melatonin, produced by the pineal gland, regulates the sleep-wake cycle by responding to light and darkness in the environment. It plays a crucial role in signaling the body when it's time to sleep and wake up, helping to establish and maintain a healthy circadian rhythm. Thyroxine, Insulin, and Cortisol do not directly regulate the sleep-wake cycle, making them incorrect choices for this question.