FINAL: Skeletal System Function & Histology

Question 1

What is the skeletal system

Answer 1

A dynamic system of connective tissue
Balance between production and remodeling

Question 2

What are the functions of bones

Answer 2

Support
Protection
Movement
Electrolytes and Acid/Base balance
Blood cell differentiation (Hematopoiesis)

Question 3

How many bones are humans born with

Answer 3

Over 300

Question 4

How many bones do adults have

Answer 4

206

Question 5

Sesamoid bone

Answer 5

Small bones
Embedded within tendon where is passes over a joint
Ex: patella

Question 6

Wormian bones

Answer 6

Extra irregularly shaped bone pieces that occur within a suture in the cranium

Question 7

What part of the long bone is this

Answer 7

Diaphysis (shaft)

Question 8

What part of the long bone is this

Answer 8

Epiphysis (end of long bone)
Top - proximal epiphysis
Bottom - distal epiphysis

Question 9

What part of the long bone is this

Answer 9

Metaphysis (growth plate region)

Question 10

What part of the long bone is this

Answer 10

Medullary cavity (filled with yellow bone marrow)

Question 11

What part of the long bone is this

Answer 11

Endosteum (inside)
- connective tissue lining medullary cavity
- contains osteogenic (bone-forming) cells

Question 12

What part of the long bone is this

Answer 12

Periosteum (outside)
- connective tissue covering bone but not the cartilage
- osteogenic (bone-forming) cells and blood vessels that nourish or help with repairs

Question 13

What part of the long bone is this

Answer 13

Articular cartilage
- covers joint to reduce friction & absorb shock

Question 14

What are the two types of bone marrow

Answer 14

Red marrow and yellow marrow

Question 15

What is red marrow

Answer 15

Found at epiphysis of long bones & spongy bone
Site for hematopoiesis (blood cell formation)

Question 16

What is yellow marrow

Answer 16

Found within the medullary cavity
Stores fat

Question 17

What are the types of tissue that bones are composed of

Answer 17

Cartilage
Osseous tissue
Epithelium
Nerve
Blood forming tissue
Adipose
Dense connective tissue

Question 18

What is osseous tissue

Answer 18

Connective tissue normally called “bone”

Question 19

What are the 3 basic components of connective tissue

Answer 19

Cells
Fibers
Ground substance

Question 20

What makes up the matrix of connective tissue

Answer 20

50% ground substance
25% collagen fibers
25% water

Question 21

What does osseous tissue consist of

Answer 21

Bone cells with a mineralized matrix

Question 22

What are osteoprogenitor (osteogenic) cells

Answer 22

• stem cells
• divide to replace themselves or to produce osteoblasts and osteocytes
• found in periosteum, endosteum

Question 23

What are osteoblasts

Answer 23

• secrete unmineralized bone matrix (osteoid)
• some mature into osteocytes

Question 24

What are osteoids

Answer 24

Collagen, calcium-binding proteins

Question 25

What are osteocytes

Answer 25

- mature bone cells - help maintain surrounding matrix - act as stress or strain sensors - communicate with other bone cells to regulate bone growth and resorption

Question 26

What are osteoclasts

Answer 26

- cells of matrix destruction - derived from the same stem cells that become white blood cells - large, multinucleate cells - responsible for bone resporption (destruction)

Question 27

What does the osteon consist of

Answer 27

Concentric layers of bone matrix called lamellae surrounding a central canal (Haversian canal)

Question 28

What is the red arrow pointing to

Answer 28

The volkmann’s canal - how Haversian canals are connected - network of blood vessels

Question 29

Where are osteocytes located

Answer 29

Small pockets called lacunae

Question 30

What are the small channels that allow osteocytes to communicate with one another and receive nutrients

Answer 30

Canaliculi

Question 31

What is this red line pointing to on the osteon

Answer 31

Canaliculi

Question 32

What is this component of an osteon

Answer 32

Lamallae

Question 33

What is this component of an osteon

Answer 33

Haversian canal

Question 34

What is this component of an osteon

Answer 34

Lacunae with osteocytes inside

Question 35

What is the purpose of the harness of the matrix

Answer 35

To provide resistance to diffusion

Question 36

What happens to osteoblasts producing osteoid/matrix

Answer 36

They become trapped and differentiate into osteocytes

Question 37

Are there osteon in spongy bone

Answer 37

No true osteons in spongy bone

Question 38

What is this part of spongy bone

Answer 38

Trabeculae