Calcitriol ($$1,25\text{-dihydroxyvitamin D})$$

Question 1

Which process is primarily responsible for the degradation of bone surface, as shown in the first image, and which cell type is involved?

Accepted Answer

Bone resorption by osteoclasts

Question 2

A patient undergoes a DEXA scan (as shown in the second image). What does the T-score from this scan represent?

Accepted Answer

Comparison of bone density to a healthy 30-year-old

Question 3

Referencing the third image, which hormone is released when blood calcium levels are low, and what is its primary effect?

Accepted Answer

Parathyroid hormone (PTH); stimulates osteoclasts to release calcium from bone

Question 4

Based on the fourth image, which food provides the highest amount of calcium per serving?

Accepted Answer

Sardines, canned

Question 5

According to the fifth image, which food is a significant source of phosphorus but not a dairy product?

Accepted Answer

Lentils, cooked

Question 6

Using the sixth image, what is the recommended daily intake of magnesium for adult men aged 19–30 years?

Accepted Answer

$$400\ 	ext{mg}$$

Question 7

The seventh image shows teeth with white spots and pitting. What condition does this represent, and what is its cause?

Accepted Answer

Fluorosis caused by excess fluoride

Question 8

Referencing the eighth image, what is the final active form of vitamin D produced in the kidneys?

Accepted Answer

Calcitriol ($$1,25	ext{-dihydroxyvitamin D})$$

Question 9

The ninth image shows a map of North America. Why are individuals living north of the 37° latitude at higher risk for vitamin D deficiency?

Accepted Answer

UV light exposure is insufficient for vitamin D synthesis during winter months

Question 10

Based on the tenth image, which food provides the highest amount of vitamin D per serving?

Accepted Answer

Salmon, pink, canned

Question 11

The eleventh image shows a child with bowed legs. What condition is most likely present, and what is the underlying nutritional deficiency?

Accepted Answer

Rickets caused by vitamin D deficiency

Question 12

The twelfth image compares normal bone to osteoporotic bone. What is the primary structural difference?

Accepted Answer

Osteoporotic bone has decreased density and more porous structure

Question 13

The thirteenth image shows X-rays of hip bones. What is a key radiographic feature of osteoporotic bone compared to healthy bone?

Accepted Answer

Osteoporotic bone shows thinner and more fragile structure

Question 14

The fourteenth image shows microscopic views of bone. Which side represents osteoporotic bone, and what is the consequence of this structure?

Accepted Answer

Right side; increased risk of fractures

Question 15

The fifteenth image illustrates changes in posture with age. What condition is depicted, and what is a common symptom?

Accepted Answer

Osteoporosis; decline in height and kyphosis

Question 16

The sixteenth image shows a person with a curved upper spine. What is this condition called, and what is its primary cause?

Accepted Answer

Kyphosis (dowager’s hump); osteoporosis

Question 17

The seventeenth image shows a graph of bone mineral density in females. What happens to bone density after menopause?

Accepted Answer

Bone density decreases rapidly, increasing fracture risk

Question 18

The eighteenth image shows a person engaging in physical activity. Which type of exercise is most beneficial for bone health?

Accepted Answer

Weight-bearing exercise (e.g., jogging, walking)

Nutrients in Bone Metabolism and Osteoporosis: A Comprehensive Study Guide

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