Bone

Question 1

What is an osteocyte??

Answer 1

Bone cell.

Question 2

What is a lacunae??

Answer 2

Area directly surrounding osteocytes.

Question 3

What is a canaliculi??

Answer 3

Small channels between lacunae that allow for communication between osteocytes.

Question 4

What is the main component of bone??

Answer 4

Hydroxyapatite

Question 5

What does proximal mean??

Answer 5

Closest side in relation to torso.

Question 6

What does distal mean??

Answer 6

Furthest side in relation to torso.

Question 7

What is the epiphysis??

Answer 7

Ends of the bone.

Question 8

What is the metaphysis??

Answer 8

Section of the bone in-between the epiphysis and the diaphysis.

Question 9

What is the diaphysis??

Answer 9

Middle of the bone.

Question 10

What is the epiphyseal plate??

Answer 10

Structure at the ends of bones that allow for lengthwise growth of the bone.

Question 11

What is the medullary cavity??

Answer 11

Central cavity of the bone where bone marrow is store.

Question 12

What is the endosteum??

Answer 12

Thin tissue that lines the inside of bones.

Question 13

What is a lamellae??

Answer 13

Ring of bone tissue.

Question 14

What is an osteon??

Answer 14

Structural unit of compact bone tissue.

Question 15

What is trabeculated bone??

Answer 15

Spongy bone.

Question 16

What is an osteoclast??

Answer 16

Bone cell that breaks down bone tissue.

Question 17

What is an osteoblast??

Answer 17

Bone cell that secretes bone tissue and eventually develops into an osteocyte.

Question 18

What are the developmental steps for osteocytes and bone-lining cells??

Answer 18

1. Mesenchymal Stem Cell
2. Osteoprogenitor Cell
3. Osteoblast
4. Osteocyte and Bone-lining cell

Question 19

What are the developmental steps for osteoclasts??

Answer 19

1. Granulocyte/Monocyte Progenitor Cell
2. Inactive Osteoclast
3. Active Osteoclast

Question 20

What is osteoid??

Answer 20

Matrix excreted by osteoblasts that eventually calcifies into bone tissue.

Question 21

Does intramembranous ossification involve cartilage??

Answer 21

No

Question 22

Does endochondral ossification involve cartilage??

Answer 22

Yes

Question 23

What is the basic development steps for endochondral ossification??

Answer 23

1. Creation of the Cartilage Model
2. Chondrocytes in Cartilage Model calcify matrix, then die and break down.
3. Blood vessels invade and grow into the perichondrium of the cartilage model.
4. Osteoclasts invade the perichondrium and begin to erode the cartilage.
5. Osteoblasts lay down spongy bone.
6. Osteoblasts also convert the perichondrium into the periosteum.
7. Cartilage model continues to grow lengthwise and repeats the process.
8. Around time of birth, epiphyseal arteries invade the epiphyses and begin the process of converting the cartilage into spongy bone. This results in cartilage only remaining in the epiphyseal plate and in the articular cartilage.

Question 24

How is intramembranous bone and endochondral ossified bone distinguished histologically??

Answer 24

Endochondral ossified bone has mixed spicules.

Question 25

What are the 5 Zones of the Epiphyseal Growth Plate??

Answer 25

1. Zone of Reserved Cartilage
2. Zone of Proliferation
3. Zone of Hypertrophy
4. Zone of Calcified Cartilage
5. Zone of Resorption