Histology

Question 1

Articular cartilage (hyaline)

Answer 1

The smooth, white tissue that covers the ends of bones where they come together to form joints.

Question 2

Canaliculi

Answer 2

Channels from the lacuna which house the cellular processes from the osteocyte

Question 3

Cancellous (spongy, trabecular) bone

Answer 3

• scaffolding appearance
• large soft tissue spaces
• rarely includes vascular canals or osteons
• located in ends of bones and in association with marrow

Question 4

Compact (cortical) bone

Answer 4

The dense outer surface of bone that forms a protective layer around the internal cavity

Question 5

Diaphysis

Answer 5

The main or midsection (shaft) of a long bone. It is made up of cortical bone and usually contains bone marrow and adipose tissue (fat).

Question 6

Endosteum

Answer 6

A thin vascular membrane of connective tissue that lines the inner surface of the bony tissue that forms the medullary cavity of long bones.

Question 7

Epiphysis

Answer 7

Secondary center

The end part of a long bone, initially growing separately from the shaft

Question 8

Haversian system (canal)

Answer 8

• named after Clopton Havers

- central canal of the osteon, containing the vascular bundle (arterioles, venules, lymphatics and nerves, plus marrow)

Question 9

Interstitial lamella

Answer 9

One of the lamellae of partially resorbed osteons occurring between newer, complete osteons.

Question 10

Lacuna

Answer 10

Cell spaces to house osteocytes

Question 11

Lamellar bone

Answer 11

• compact bone
• dense bone structure
• highly organized
• limited soft tissue spaces
• highly vascular
• organized into Haversian systems

Question 12

Medullary cavity

Answer 12

The medullary cavity (medulla, innermost part) is the central cavity of bone shafts where red bone marrow and/or yellow bone marrow (adipose tissue) is stored; hence, the medullary cavity is also known as the marrow cavity.

Question 13

Metaphysis (growth plate)

Answer 13

The narrow portion of a long bone between the epiphysis and the diaphysis. It contains the growth plate, the part of the bone that grows during childhood and as it grows, it ossifies near the diaphysis and the epiphyses.

Question 14

Osteoblast

Answer 14

• bone makers
• arise from mesenchymal cells
• produce bone matrix known as osteoid
• as it is encased in matrix, it will reside in a lacuna and become an osteocyte

Question 15

Osteoclast

Answer 15

• bone breakers
• arises from mesenchymal cells
• giant multinucleated phagocytic cell
• resorbs and remodels bone and cartilage
• resides in Howship’s lacuna

Question 16

Osteocyte

Answer 16

• arise from osteoblast
• maintain bone matrix and may release calcium
• numerous processes interconnecting them
• reside in lacuna

Question 17

Osteon

Answer 17

Chief structural unit of compact (cortical) bone, consisting of concentric bone layers called lamellae, which surround a long hollow passageway,

Question 18

Periosteum

Answer 18

A membrane that covers the outer surface of all bones, except at the joints of long bones.

Question 19

Primary center of ossification

Answer 19

Located in the shaft

Question 20

Secondary center of ossification

Answer 20

Located in the epiphysis

Question 21

Sharpey’s fibres

Answer 21

Any of the thready processes of the periosteum that penetrate the tissue of the superficial lamellae of bones

Question 22

Volkmann’s canal

Answer 22

Connecting branches between Haversian canals, feed intersitial lamellae

Question 23

Woven bone

Answer 23

• fetal bone
• poorly organized and weak bone
• large vascular spaces

Question 24

Intramembranous ossification

Answer 24

• appositional growth
• no cartilaginous model
• mesenchymal cells differentiate into osteoblasts
• bone matrix is layered down
• osteocytes and canaliculi are evident

Question 25

Endochondral ossification

Answer 25

• associated with growth phase and repair
• originate from a cartilaginous model
• cartilage cells replaced by bone cells
• ## growth occurs in length and width