Bone is a connective tissue with a mineralized extracellular matrix (calcium phosphate crystals) that gives it hardness and rigidity.
Category: Chapter 6
Question 2
Osteoclasts are the cells responsible for building new bone tissue.
Correct Answer
False
Osteoblasts build new bone tissue by secreting the organic matrix (osteoid). Osteoclasts are the cells that break down (resorb) bone tissue.
Category: Chapter 6
Question 3
The diaphysis is the shaft of a long bone.
Correct Answer
True
The diaphysis is the elongated shaft of a long bone, composed of compact bone surrounding a medullary cavity that contains yellow bone marrow in adults.
Category: Chapter 6
Question 4
Red bone marrow produces red blood cells.
Correct Answer
True
Red bone marrow is the site of hematopoiesis (blood cell formation). It produces red blood cells, white blood cells, and platelets.
Category: Chapter 6
Question 5
Compact bone is found in the interior of flat bones.
Correct Answer
False
Spongy (cancellous) bone is found in the interior of flat bones (and at the epiphyses of long bones). Compact bone forms the dense outer layer.
Category: Chapter 6
Question 6
The periosteum is a membrane that lines the medullary cavity.
Correct Answer
False
The periosteum is the membrane that covers the outer surface of bones. The endosteum is the membrane that lines the medullary cavity.
Category: Chapter 6
Question 7
Osteoporosis is characterized by decreased bone density and increased fracture risk.
Correct Answer
True
Osteoporosis results from an imbalance where bone resorption exceeds bone formation, leading to porous, weakened bones that fracture easily.
Category: Chapter 6
Question 8
An epiphyseal plate is the growth plate found in mature adult bones.
Correct Answer
False
The epiphyseal plate (growth plate) is found in growing bones of children and adolescents. In adults, it has been replaced by the epiphyseal line after growth is complete.
Category: Chapter 6
Question 9
Calcium is stored in bones and can be released into the blood when needed.
Correct Answer
True
Bones serve as the body's calcium reservoir. When blood calcium levels drop, parathyroid hormone stimulates osteoclasts to break down bone and release calcium into the blood.
Category: Chapter 6
Question 10
Osteocytes are mature bone cells trapped within lacunae.
Correct Answer
True
Osteocytes are mature bone cells that were once osteoblasts. They become trapped in small spaces called lacunae within the mineralized bone matrix.
Category: Chapter 6
Question 11
Long bones are longer than they are wide.
Correct Answer
True
Long bones have a shaft (diaphysis) that is longer than it is wide, with epiphyses at each end. Examples include the femur, humerus, and phalanges.
Category: Chapter 6
Question 12
Intramembranous ossification forms most of the bones in the body.
Correct Answer
False
Endochondral ossification forms most of the bones in the body. Intramembranous ossification forms the flat bones of the skull, clavicles, and mandible.
Category: Chapter 6
Question 13
The Haversian system (osteon) is the structural unit of compact bone.
Correct Answer
True
An osteon consists of concentric rings (lamellae) of bone matrix surrounding a central (Haversian) canal that contains blood vessels and nerves.
Category: Chapter 6
Question 14
Calcitonin is released when blood calcium levels are too low.
Correct Answer
False
Calcitonin is released by the thyroid gland when blood calcium levels are too high. It inhibits osteoclast activity to reduce calcium release from bone. Parathyroid hormone is released when calcium is low.
Category: Chapter 6
Question 15
Wolff's law states that bones grow thicker in response to mechanical stress.
Correct Answer
True
Wolff's law describes how bones adapt to the loads placed on them. Increased stress leads to increased bone deposition, making bones stronger in areas of higher mechanical demand.
Category: Chapter 6
Question 16
Fracture repair begins with the formation of a hematoma at the fracture site.
Correct Answer
True
When a bone fractures, blood vessels are torn, forming a hematoma (blood clot). This is the first step in the repair process, followed by fibrocartilaginous callus, bony callus, and remodeling.
Category: Chapter 6
Question 17
Articular cartilage covers the diaphysis of long bones.
Correct Answer
False
Articular cartilage (hyaline cartilage) covers the epiphyses at joints, not the diaphysis. It reduces friction and absorbs shock at joint surfaces.
Category: Chapter 6
Question 18
Bone is a dynamic tissue that is continuously being remodeled throughout life.
Correct Answer
True
Bone undergoes constant remodeling through the coordinated activity of osteoblasts (building bone) and osteoclasts (breaking down bone). About 10% of the skeleton is replaced each year in adults.
Category: Chapter 6
Question 19
Spongy bone has a solid, dense appearance with no visible spaces.
Correct Answer
False
Spongy bone has an open lattice-like structure made of trabeculae with spaces between them. It appears porous, unlike compact bone which has a solid, dense appearance.
Category: Chapter 6
Question 20
Vitamin D is essential for proper calcium absorption from the digestive tract.
Correct Answer
True
Vitamin D promotes the absorption of calcium from the small intestine. Without adequate vitamin D, calcium absorption is impaired, which can lead to weak bones.
Category: Chapter 6