Lecture 13- Skeletal System Pt 2

Question 1

What is the area of growth called in a long bone?

Answer 1

Epiphyseal plate

Question 2

On the _____ side, cartilage is formed

Answer 2

Epiphyseal

Question 3

On the ____ side, cartilage is ossified (replaced with bone tissue)

Answer 3

Diaphyseal

Question 4

What is the function of the reserve zone?

Answer 4

Anchor epiphyseal plate to osseous tissue of epiphysis

Contains small chondrocytes within matrix

Question 5

What is the function of the proliferative zone?

Answer 5

Makes new chondrocytes

Contains stacks of slightly larger chondrocytes

Question 6

What is the function of the maturation and hypertrophy zone?

Answer 6

Chondrocytes mature and grow

Chondrocytes are older and larger

Question 7

What is the function of. the calcified matrix zone?

Answer 7

Chondrocytes become calcified and die

Contains mostly dead chondrocytes

Question 8

What is the function of the ossification zone?

Answer 8

Calcified matrix connects epiphyseal plate to diaphysis

Bone grows in length when osseous tissue is added to diaphysis

Question 9

What has to happen for bone to stop growing?

Answer 9

Chondrocytes in the epiphyseal plate stop proliferating AND bone replaces the cartilage

Question 10

What process is responsible for longitudinal growth of long bone due to cartilage being ossified?

Answer 10

Endochondral ossification

Question 11

What is appositional growth?

Answer 11

The increase in the diameter of bones by the addition of bone tissue at the surface of bones

Question 12

What two things must happen for bone to increase in diameter

Answer 12

1. Osteoclasts resorb old bone
2. Osteoblasts produce new bone tissue through intramembranous ossification

Question 13

Which cell type below has the longest life span

Osteoblast
Osteoclast
Osteocyte
Osteogenic cells

Answer 13

Osteocytes

Trapped in bone matrix and can survive entire lifetime

Question 14

Which is not a function of the skeleton system?

Support
Movement
Mineral and energy storage
Digestion
Hematopoiesis

Answer 14

Digestion

Question 15

Where does bone remodeling take place?

Answer 15

Basic multicellular unit (BMU)

Question 16

What are the 5 steps in bone remodeling? What is the function?

Answer 16

1. Origination- some injury to bone
2. Activation-pre osteoclasts form osteoclasts
3. Resorption- osteoclasts bind to bone tissue and release acidic contents
4. Formation- osteoblasts form bone matrix/osteoid
5. Mineralization- osteoid gets calcified and osteoblasts become osteocytes

Only Active Rats Find Mates

Question 17

______ is the master regulator of bone remodeling

Osteoblast
Osteoclast
Osteocyte
Osteogenic cells

Answer 17

Osteocyte

Gives signals to osteoblasts and osteoclasts to coordinate their activity

Question 18

Which part of the RANK-RANK-L-OPG system is solely used for bone formation?

Answer 18

OPG

Question 19

Which part of the RANK-RANK-L-OPG-SOST system is used to clear bone tissue away?

Answer 19

RANK
RANK-L
SOST

Question 20

RANK-L binding to RANK triggers the synthesis of _______

Answer 20

Osteoclasts

Promotes osteoclastogenesis

Question 21

What does OPG inhibit?

Answer 21

RANK-L from binding to RANK receptor to form bone

Question 22

What does SOST inhibit?

Answer 22

Osteoblasts/bone formation

Activates bone resorption

Question 23

What is bone resorption?

Answer 23

The osteoclasts remove bone by dissolving the mineral and breaking down the matrix

Question 24

What is a consequence of high bone density?

Answer 24

Difficulty staying afloat while swimming

Question 25

All of the following are characteristics of bone density except:

-Wide/deep maniple
-Weight loss
-Narrow medullary cavity
-Dense vertebrae

Answer 25

Weight loss

Would actually feel heavier because of high bone density

Question 26

How does osteoblast and osteoclast activity alter as we age?

Answer 26

Osteoblast activity- decreases
Osteoclast activity- increases

Question 27

How do females differ from males in bone calcium levels as they age?

Answer 27

Females have a more dramatic decline in calcium levels due to menopause

Low bone mass leads to increased fractures

Question 28

What is osteoporosis? What does this lead to?

Answer 28

Progressive systemic skeletal disease characterized by low bone mass/micro deterioration of bone tissue—>Bone fragility/increased susceptibility to bone fractures

Question 29

What is a major way to reduce osteoporosis?

Answer 29

Engage in weight bearing exercises

Question 30

If you become immobilized, how much bone would you lose on average during the first year following this injury?

10%
20%
30%
50%

Answer 30

50%

Question 31

List at least 4 risk factors for osteoporosis

Answer 31

1. Early menopause (before 45)
2. Eating disorders as pre-teen/teen
3. Small body frames
4. Family history of osteoporosis
5. Early malnutrition
6. Low Vitamin D
7. Certain medications
8. Intestinal pathology
9. Going to space lol