Skeletal Systems I

Question 1

List the functions of bone & Skeletal system

Answer 1

1.Support
2.Protection
3.Assist movement
4.Mineral homeostasis
5.Blood cell Protection
6.Triglyceride Storage (stores yellow bone marrow/potential energy reserve.

Question 2

List the bone Structure

Answer 2

1. Epiphyses - Proximal & distal ends
2. Diaphysis - Main shaft
3. Metaphases- Contains epiphyseal growth plate.
4. Articles cartilage- Reduces friction and absorb shock. Covers the epiphyses

5.Periosteum-Surrounds external bone surface | Osteogenic layer Connective tissue.

6. Medullary cavity – Houses bone marrow
7. Endosteum – Lines internal bone surface

Question 3

List the 4 types of Bone cells

Answer 3

Osteogenic cell
Osteoblast
Osteocyte
Osteoclast

Question 4

Which Bone cell maintains bone tissue?

Answer 4

Osteocyte

Question 5

What is the function of an Osteoblast cell?

Answer 5

Forms Bone matrix

Question 6

What is an Osteoclast?

Answer 6

An Osteoclast is a bone cell. Its function is for resorption of bone matrix.

Question 7

What do blood vessels and nerves penetrate bone via?

Answer 7

Volkmanns canals

Question 8

What are the features of compact bone?

Answer 8

Strongest form of bone tissue
Arranged into structural units – Osteons
Canals surrounded by concentric lamellae
It forms intricate canal network.

Question 9

Compact bone contain a Lacunae; what does the lacunae contain?

Answer 9

Osteocytes

Question 10

What connects Osteocytes in compact bone?

Answer 10

Canaliculi

Question 11

What is spongy bone arranged into?

Answer 11

Trabeculae

Question 12

Explain the arrangement of spongy bone.

Answer 12

Spongy bone is arranged into trabeculae. There is space between trabeculae. This allows bones to be slighter.

Question 13

What bones are mainly made of spongy bone?

Answer 13

Short, Flat & Irregular bones
(This is always covered by a layer of compact bone)

Question 14

What bone cells do spongy bone contain?

Answer 14

osteocytes, osteoblasts & osteoclasts

Question 15

Explain function of periosteum

Answer 15

Surrounds external bone surface. Connective tissue, Osteogenic

Question 16

Which is a non specific cell Osteogenic cell or osteoclast?

Answer 16

Answer: Osteogenic-undergo cell division

Osteoclast is for resorption of bone matrix.

Question 17

Bone Homeostasis. Which cell?

Answer 17

Osteoblast and Osteoclast

Bone formation and Bone resorption

Question 18

Lines of stress change over time in the same direction of bone stress. True or false?

Answer 18

True. Example femur
Baby crawling——child walking

Question 19

Does compact bone and spongy bone contain the same bone cells? And what are they?

Answer 19

They contain the same bone cell
Osteocytes, Osteoblasts and Osteoclasts.

Question 20

Which contains red bone marrow, compact bone or spongy bone?

Answer 20

Spongy bone.

Question 21

How is compact bone arranged?

Answer 21

Compact bone is arranged in structural units Osteons

Canals are surrounded by Concentric Lamellae These are rings of calcified extracellular matrix.

Osteons Align in the same direction as lines of stress. This can change over time.

Question 22

Where does the Periosteal artery enter?

Answer 22

The diaphysis through the volkmann canals

Question 23

What does the nutrient artery split into?

Answer 23

Nutrient artery divides into proximal & distal branches – Supply inner
compact bone, diaphysis & spongy bone

Question 24

Where is the metaphyseal found? What does it contain?

Answer 24

Found in the metaphyses and supplies red bone marrow.

Question 25

What does Epiphyseal arteries contain and where is it found>?

Answer 25

Supply red bone marrow & epiphyses

Question 26

Do bones contain veins?

Answer 26

Yes (they match the artery)

Question 27

What is intramembranous ossification?

Answer 27

The initial bone development

Question 28

How many steps for intramembranous ossification?

Answer 28

6

Question 29

What is the first step of intramembranous ossification?

Answer 29

Development of cartilage model Formed by *chondroblasts* surrounded by *perichondrium*

Question 30

What is step 2 of intramembranous ossification?

Answer 30

Growth of cartilage model. Interstitial growth- cell division of chondrocytes Apposition growth. The extracellura metric begins to calcify.

Question 31

Step 3 intramembranous ossification

Answer 31

Development of primary ossification Nutrient artery penetrates perichondrium. This stimulates cell to differentiate from chondroblasts to osteoblast.

Question 32

Explain further step 3 of intramembranous ossification

Answer 32

Periocondrium starts to form bone. Primary ossification centre is induced by capillaries forming into calcified cartilage. Then Osteoblasts deposit bone extracellular matrix over the calcified cartilage.

Question 33

What induces growth of the primary ossification centre?

Answer 33

Capillary growth into calcified cartilage.

Question 34

Explain step 4 of intramembranous ossification?

Answer 34

Development of Medullary cavity. Osteoclasts break down some Spongy bone trabeculae. (Unit structure) This leaves a cavity in the diaphysis. The wall of diaphysis is replaced by compact bone.

Question 35

Step 5 of intramembranous ossification

Answer 35

Development of Secondary ossification centres Branches of epiphyseal artery enters the epiphysis. Spongy bone remains in the interior aspect of the epiphyses.

Question 36

Step 6 intramembranous ossification

Answer 36

Formation of articulatar cartilage and epiphyseal plate. Until adulthood, hyaline cartilage remains between diaphysis and epiphysis as the epiphyseal growth plate. The epiphyseal growth plate is responsible for lengthwise growth of long bone.

Question 37

Both growth is linked to what two events?

Answer 37

Interstitial growth of cartilage Replacement of cartilage

Question 38

How many zones of the epiphyseal growth plate?

Answer 38

4

Question 39

List the zones that make up the epiphyseal growth plate

Answer 39

Zone of Resting Cartilage Zone of Proliferating Cartilage Zone of Hypertrophic Cartiliage Zone of Calcified Cartiliage

Question 40

What is appositional growth?

Answer 40

Bone thickness