Histology-World!

 

 

 

Histology Testbank: Bone 2a

 

Instructions: For each histology question, pick the one best answer. This histology test bank is also useful for the histology questions on the USMLE (USMLE step 1).

1.
What is dense bone?
a. Immature bone
b. Cancellous bone
c. Compact bone
d. Woven bone
e. Spongy bone

Answer: c

Compact bone is also called dense bone. Compact bone has the Haversian system.

Immature bone is woven bone. It is nonlamellar bone or bundle bone.

Spongy bone is also referred to as cancellous bone. The mineralized tissue is seen as spicules. Marrow spaces are also present.

2.
Which cell is a resting osteoblast?
a. Chondrocyte
b. Chondroblast
c. Osteocyte
d. Osteoclast
e. Bone lining cell

Answer: e

The mature cell in cartilage is a chondrocyte. It rests in a lacunae surrounded by matrix. A chondroblast is an immature cartilage cell which produces the cartilaginous matrix. An osteocyte is a mature bone cell. An osteoclast is a bone cell which is involved in resorption of bone. A bone lining cell is a resting osteoblast.

3.
What are the mineral crystals in bone called?
a. Hydroxyapatite
b. Calcite
c. Tourmaline
d. Rubellite
e. Indicolite

Answer: a

Calcium is in a mineral structure in bone and tooth enamel called hydroxyapatite. The chemical formula is [Ca10 (PO4)6(OH)2]

Calcite crystals are calcium carbonate. The main component of limestone is calcite and seashells are made of calcite. However, calcite crystals are not found in man.

Tourmaline is a crystal found in nature. Pink-red tourmaline is called rubellite. Blue tourmaline is known as indicolite. Tourmaline crystals are not found in man, although sometimes they are found on the necks and fingers of women in the form of jewelry.

4.
What is the cylindrical structure in compact bone?
a. Osteoclast
b. Osteon
c. Osteocyte
d. Osteoblast
e. Osteoid

Answer: b

An osteoclast is a multinucleated cell involved in the degradation of bone. It is a bone resorbing cell.

An osteon is the cylindrical structure with bone. An osteon is also called a Haversian system.

The mature bone cell is called an osteocyte. It sits in a space, called a lacuna.

An osteoblast is an immature bone cell. The osteoblast is the bone forming cell.

Osteoid is unmineralized bone matrix.

5.
What are Sharpey's fibers?
a. Elastic fibers
b. Collagen fibers
c. Reticular fibers
d. Trabeculae
e. Dense regular connective tissue

Answer: b

Sharpey's fibers are collagen fibers that extend into a bone at an angle.

6.
What is the space that an osteocyte rests in?
a. Canaliculi
b. Sharpey's fibers
c. Trabeculae
d. Tome's process
e. Lacuna

Answer: e

Canaliculi are the little tunnels within bone.

Sharpey's fibers are collagen fibers that extend into a bone at an angle.

Trabeculae are the spicules seen with spongy bone.

Tome's process is seen in teeth, this process is responsible for enamel production.

An osteocyte rests in a space called a lacuna.

7.
What is bone formation called when the bone is formed from a cartilage template?
a. Intraosseous
b. En bloc
c. Intramembranous
d. Endochondral
e. Endosteum

Answer: d

Intramembranous bone formation is the process of bone formation where the bone is formed without a cartilage template. Endochondral bone formation is the process of bone formation where the bone is formed using a cartilage template.

8.
What is the primary component of red marrow?
a. Hematopoietic tissue
b. Fat
c. Cartilage
d. Fibrous tissue
e. Bone

Answer: a

Red marrow contains active hematopoietic tissue. Yellow marrow is primarily fat.

9.
What cell is an immature bone cell?
a. Osteoclast
b. Osteon
c. Osteocyte
d. Osteoblast
e. Osteoid

Answer: d

An osteoclast is a multinucleated cell involved in the degradation of bone. It is a bone resorbing cell.

An osteon is the cylindrical structure with bone. An osteon is also called a Haversian system.

The mature bone cell is called an osteocyte. It sits in a space, called a lacuna.

An osteoblast is an immature bone cell. The osteoblast is the bone forming cell.

Osteoid is unmineralized bone matrix.

10.
What is bundle bone?
a. Cancellous bone
b. Compact bone
c. Dense bone
d. Spongy bone
e. Immature bone

Answer: e

Compact bone is also called dense bone. Compact bone has the Haversian system.

Immature bone is woven bone. It is nonlamellar bone or bundle bone.

Spongy bone is also referred to as cancellous bone. The mineralized tissue is seen as spicules. Marrow spaces are also present.