Question 1

Aseptic necrosis of bones may be caused by all the following except:
A) Sickle cell anemia
B) Thrombotic occlusion of a nutrient artery
C) Trauma
D) Bacteria
E) Drugs

Accepted Answer

Aseptic necrosis, also known as avascular necrosis, occurs as a result of interruption in the blood supply to a bone. This interruption can be caused by a number of factors including sickle cell anemia, thrombotic occlusion of a nutrient artery, trauma, drugs, radiation and alcohol. However, bacteria are not typically a cause of aseptic necrosis.

Question 2

Bowlegs,craniotabes,and rachitic rosary in a growing child are signs of:
A) Osteoporosis
B) Osteopetrosis
C) Vitamin B₁ deficiency
D) Vitamin D deficiency
E) Vitamin A deficiency

Accepted Answer

Bowlegs, craniotabes (softening and thinning of the skull bones), and rachitic rosary (prominence of the costochondral junctions) are classic signs of rickets, a condition caused by a deficiency in vitamin D. Vitamin B₁ deficiency can lead to beriberi but does not cause these specific bone abnormalities. Vitamin A deficiency can lead to night blindness, but it does not cause these bone abnormalities. Osteoporosis is a condition of decreased bone density that typically occurs in adults, not growing children. Osteopetrosis is a rare genetic disorder characterized by increased bone density, which would be unlikely to present with the above symptoms.

Question 3

A tumor in a 15-year-old boy was diagnosed in the diaphysis of the tibia.On x-ray examination,it had a sunburst appearance and histologically it was composed of a uniform population of small blue cells.This tumor is a(n):
A) Osteosarcoma
B) Chondrosarcoma
C) Giant cell tumor
D) Ewing's sarcoma
E) Metastasis from a lung cancer

Accepted Answer

The sunburst appearance on X-ray and a uniform population of small blue cells seen on histology is characteristic of Ewing's sarcoma, a bone cancer that typically affects adolescents and young adults. Osteosarcoma and chondrosarcoma are also bone cancers but have different histological features. Giant cell tumor is a benign tumor, while metastasis from a lung cancer would have different imaging and histological features.

Question 4

The most common primary malignant tumor of bones is called:
A) Osteosarcoma
B) Chondrosarcoma
C) Paget's disease
D) Ewing's disease
E) Giant cell tumor of bone

Accepted Answer

Osteosarcoma is the most common primary malignant tumor of bones, accounting for about 35% of all primary bone tumors. Chondrosarcoma is the second most common, followed by Ewing's sarcoma, giant cell tumor of bone, and others. Paget's disease is not a malignant tumor but a disorder of bone remodeling.

Question 5

If a long bone fracture has numerous lines and fragments,it is called:
A) Simple
B) Greenstick
C) Comminuted
D) Complete
E) Incomplete

Accepted Answer

A comminuted fracture is when a bone breaks into several fragments, often with multiple lines of fracture.

Question 6

Osteosarcomas most often arise in the bones of the:
A) Skull
B) Vertebrae
C) Fingers
D) Toes
E) Knee

Accepted Answer

Osteosarcomas typically arise in the bones of the knee, specifically in the distal femur or proximal tibia. While osteosarcomas can occur in other bones, such as the skull or vertebrae, they are most commonly found in the knee. And while finger and toe bones are not immune to developing osteosarcomas, they are a rare site for occurrence.

Question 7

Which joint disease is characterized by destruction and loss of cartilage,sclerosis of subchondral bone,cyst formation,and osteophytes?
A) Osteoarthritis
B) Osteomalacia
C) Rheumatoid arthritis
D) Gout
E) Infectious arthritis

Accepted Answer

These are the classic features of osteoarthritis, the most common joint disease.

Question 8

The extracellular organic matrix of bones is called:
A) Osteon
B) Osteoid
C) Osteoblast
D) Osteocyte
E) Osteoclast

Accepted Answer

The extracellular organic matrix of bones is called osteoid. Osteon refers to the basic histological unit of compact bone tissue. Osteoblast, osteocyte, and osteoclast are all types of bone cells.

Question 9

Which vitamin is essential for the formation of bones?
A) Vitamin A
B) Vitamin B₁
C) Vitamin B₁₂
D) Vitamin D
E) Vitamin E

Accepted Answer

Vitamin D is essential for the absorption of calcium and phosphorus, which are necessary for the formation and maintenance of strong bones. Without sufficient vitamin D, bones can become soft, brittle, and prone to fractures.

Question 10

Benign bone tumor composed of cartilage cells is called:
A) Osteoma
B) Chondroma
C) Fibroma
D) Paget's disease
E) Ewing's disease

Accepted Answer

A tumor composed of cartilage cells is called a chondroma. Osteoma is a tumor composed of bone tissue, fibroma is a tumor composed of fibrous tissue, Paget's disease is a bone disorder causing abnormal bone growth and Ewing's disease is a malignant bone tumor.

Question 11

Which of the following diseases is an autosomal dominant cause of dwarfism?
A) Achondroplasia
B) Osteopetrosis
C) Osteogenesis imperfecta
D) Rickets
E) Osteomalacia

Accepted Answer

Achondroplasia is an autosomal dominant genetic disorder that leads to disproportionate short stature or dwarfism.

Question 12

Osteoporosis is usually diagnosed by means of:
A) Bone biopsy
B) Electron microscopy
C) X-ray examination
D) Analysis of blood
E) Analysis of joint fluid

Accepted Answer

Osteoporosis is typically diagnosed using X-ray examination, commonly known as a bone density test. This test allows doctors to measure the amount of mineral and calcium density in the bones, which helps diagnose and monitor osteoporosis. Bone biopsy, electron microscopy, analysis of blood, and analysis of joint fluid are not typically used for the diagnosis of osteoporosis.

Question 13

Which of the following diseases has the highest incidence among postmenopausal women?
A) Osteoporosis
B) Osteopetrosis
C) Osteomalacia
D) Achondroplasia
E) Osteomyelitis

Accepted Answer

Osteoporosis is a condition in which bones become brittle and fragile from loss of tissue, typically as a result of hormonal changes, or deficiency of calcium or vitamin D. Postmenopausal women are at a higher risk for osteoporosis due to the decrease in estrogen which plays a role in bone density.

Question 14

The central ("midshaft")portion of long bones is called:
A) Epiphysis
B) Metaphysis
C) Diaphysis
D) Physis
E) Anapophysis

Accepted Answer

The central or "midshaft" portion of long bones is known as the diaphysis.

Question 15

Osteogenesis imperfecta is an inborn error in the synthesis of:
A) Collagen type I
B) Collagen type II
C) Collagen type III
D) Phosphate crystals
E) Basement membranes

Accepted Answer

Osteogenesis imperfecta is a genetic disorder characterized by brittle bones that break easily. It is caused by a defect in the production of collagen type I, which is an important component of bone structure. This defect can result in bones that are weaker and more prone to fractures.

Question 16

Rheumatoid arthritis is best classified as:
A) Infectious disease
B) Degenerative disease
C) Inborn error of metabolism
D) Autoimmune disease
E) Neoplastic disease

Accepted Answer

Rheumatoid arthritis is an autoimmune disease in which the immune system attacks the body's own joints, resulting in chronic joint inflammation, pain, and deformity. It is not infectious, degenerative, inborn error of metabolism, or neoplastic.

Question 17

Softening of bones as a result of excessive resorption of calcium salts from the extracellular bone matrix is called:
A) Osteoporosis
B) Osteomalacia
C) Osteopetrosis
D) Osteitis deformans
E) Pellagra

Accepted Answer

Osteomalacia is the softening of bones due to a decrease in mineralization of the bones. This occurs as a result of excessive resorption of calcium salts from the extracellular bone matrix. Osteoporosis is also a disease that affects bone density, but it is characterized by a reduction in bone mass rather than a softening of bones. Osteopetrosis is a condition characterized by excessive bone density, while osteitis deformans is a condition characterized by abnormal bone remodeling, leading to bone deformities. Pellagra is a nutritional deficiency disease caused by niacin (vitamin B3) deficiency.

Question 18

The excess of which hormone causes osteoporosis?
A) Androgens
B) Estrogens
C) Corticosteroids
D) Prolactin
E) Glucagon

Accepted Answer

Corticosteroids are known to cause osteoporosis when present in excess. These hormones can inhibit the production of new bone tissue and can also cause existing bone tissue to break down, leading to weakened bones and increased risk of fractures. High levels of corticosteroids can be caused by long-term use of medications containing this hormone, as well as by certain medical conditions such as Cushing's syndrome.

Question 19

The bone lesions in renal osteodystrophy are caused by an excess of:
A) ACTH
B) Thyroglobulin
C) Parathyroid hormone
D) Aldosterone
E) Androgens

Accepted Answer

Renal osteodystrophy is caused by chronic kidney disease leading to mineral and bone disorder. One of the key hormones involved in this disorder is parathyroid hormone, which is increased due to the loss of kidney function. High levels of PTH cause bones to release calcium and phosphorus, leading to weak and brittle bones. Therefore, excess parathyroid hormone is the cause of bone lesions in renal osteodystrophy.

Question 20

Osteomyelitis of long bones is most often caused by:
A) Viruses
B) Pyogenic bacteria
C) Mycobacterium tuberculosis
D) Fungi
E) Parasites

Accepted Answer

Pyogenic bacteria, such as Staphylococcus aureus, are the most common cause of osteomyelitis of long bones.

Quiz 19: Bones and Joints

Aseptic necrosis of bones may be caused by all the following except:

Bowlegs,craniotabes,and rachitic rosary in a growing child are signs of:

A tumor in a 15-year-old boy was diagnosed in the diaphysis of the tibia.On x-ray examination,it had a sunburst appearance and histologically it was composed of a uniform population of small blue cells.This tumor is a(n) :

The most common primary malignant tumor of bones is called:

If a long bone fracture has numerous lines and fragments,it is called:

Osteosarcomas most often arise in the bones of the:

Which joint disease is characterized by destruction and loss of cartilage,sclerosis of subchondral bone,cyst formation,and osteophytes?

The extracellular organic matrix of bones is called:

Which vitamin is essential for the formation of bones?

Benign bone tumor composed of cartilage cells is called:

Which of the following diseases is an autosomal dominant cause of dwarfism?

Osteoporosis is usually diagnosed by means of:

Which of the following diseases has the highest incidence among postmenopausal women?

The central ("midshaft") portion of long bones is called:

Osteogenesis imperfecta is an inborn error in the synthesis of:

Rheumatoid arthritis is best classified as:

Softening of bones as a result of excessive resorption of calcium salts from the extracellular bone matrix is called:

The excess of which hormone causes osteoporosis?

The bone lesions in renal osteodystrophy are caused by an excess of:

Osteomyelitis of long bones is most often caused by: