Question 1

Which of the following best describes the main difference between compact bone and spongy bone in terms of structure and function?

Accepted Answer

Compact bone contains osteons arranged in concentric lamellae around a central canal, providing strength for weight-bearing, while spongy bone consists of trabeculae that support marrow and reduce bone weight.

Question 2

A patient presents with a bone fracture that is slow to heal. Which cell type is most directly responsible for producing new bone matrix during the repair process?

Accepted Answer

Osteoblast

Question 3

Which of the following equations correctly represents the main mineral component of bone matrix?

Accepted Answer

$$Ca_3$$($$PO_4)_2 + Ca(OH)_2$$ \rightarrow Ca_{10}($$PO_4)_6(OH)_2$

Question 4

A 65-year-old woman is diagnosed with osteoporosis. Which of the following best explains the increased risk of fractures in her bones?

Accepted Answer

Osteoclast activity exceeds osteoblast activity, leading to decreased bone density and weakened trabeculae.

Question 5

Which hormone is primarily responsible for increasing blood calcium levels by stimulating osteoclast activity, reducing renal excretion of calcium, and increasing intestinal absorption?

Accepted Answer

Parathyroid hormone (PTH)

Question 6

During endochondral ossification, what is the sequence of events leading to the formation of the primary ossification center?

Accepted Answer

Chondrocytes enlarge and die, matrix calcifies, blood vessels invade, fibroblasts become osteoblasts, and spongy bone forms.

Question 7

Which of the following best explains why regular weight-bearing exercise is recommended for maintaining healthy bones?

Accepted Answer

Mechanical stress stimulates osteoblast activity, increasing bone deposition and strength.

Question 8

A child has a genetic defect that prevents the formation of the periosteum. Which of the following consequences is most likely?

Accepted Answer

Impaired bone growth and repair due to lack of osteoprogenitor cells and poor attachment of tendons and ligaments.

Question 9

Which of the following statements about bone remodeling is correct?

Accepted Answer

Bone remodeling involves the coordinated activity of osteoblasts, osteoclasts, and osteocytes, and is influenced by mechanical stress and hormones.

Question 10

A patient with chronic kidney disease has low plasma calcium levels. Which mechanism is most likely impaired?

Accepted Answer

The kidney's ability to retain calcium and produce calcitriol, reducing intestinal absorption of calcium.

Question 11

Which of the following best describes the role of osteocytes in bone tissue?

Accepted Answer

Osteocytes maintain the bone matrix and communicate through canaliculi to regulate mineral content.

Question 12

Which of the following is a correct statement about the composition of bone matrix?

Accepted Answer

The matrix is composed of hydroxyapatite crystals for compressive strength and collagen fibers for tensile strength.

Question 13

A 14-year-old boy has not yet reached his full adult height. Which structure in his long bones is primarily responsible for continued longitudinal growth?

Accepted Answer

Epiphyseal cartilage (growth plate)

Question 14

Which of the following best explains why post-menopausal women are at higher risk for osteoporosis?

Accepted Answer

Decreased estrogen levels reduce osteoblast activity, leading to increased bone resorption by osteoclasts.

Question 15

Which of the following is a correct sequence of events in the repair of a bone fracture?

Accepted Answer

Hematoma formation, callus formation, cartilage replaced by bone, bone remodeling.

Question 16

Which of the following best describes the process of intramembranous ossification?

Accepted Answer

Mesenchymal cells differentiate into osteoblasts, which secrete osteoid and form spicules that fuse into bone.

Question 17

Which of the following is NOT a function of the skeletal system?

Accepted Answer

Synthesis of vitamin D

Question 18

A patient has a mutation that causes overactive osteoclasts. Which of the following symptoms would you expect?

Accepted Answer

Increased risk of bone fractures due to decreased bone density

Question 19

Which of the following best explains why the medullary cavity of long bones contains yellow bone marrow in adults?

Accepted Answer

Yellow bone marrow stores lipids, serving as an energy reserve.

Chapter 6: Bone Structure and Function – Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards