week 3 Lesson 1- Bone

Question 1

What is the epiphysis

Answer 1

Regions at the end of the bone
Spongy bone converted to compact bone

Question 2

What is the diaphysis

Answer 2

Middle region bone

Question 3

What is the medullary cavity

Answer 3

Found in the diaphysis. Hollow part of the bone that contains bone marrow.

Question 4

What is the epiphyseal line

Answer 4

Region where bone growth terminated in adolescence

Question 5

What is the periosteum

Answer 5

Double layer membrane around outside of bone (except Cartilage)
Outer fibrous (dense irregular)
Inner osteopenia layer (osteoblasts)

Question 6

What is the endosteum

Answer 6

A membrane that lines the inner surface of bone tissue

Question 7

Name the 2 types of bone tissue

Answer 7

Compact (cortical)
Trabecular (spongy)

Question 8

Describe compact bone tissue

Answer 8

Smooth and solid
Generally cylinder shaped

Question 9

Describe trabecular bone tissue

Answer 9

Loght porous spongy and mesh like
Structurally similar to honeycomb

Question 10

What makes up the % of the bone

Answer 10

Organic matrix- protein colllage. 10%
Mag, sodium and bicarbonate. Water 25%
Mineral calcium and phosphate 65%

Question 11

Name the function and location of osteoblasts

Answer 11

Bone formation
Growing portions of bone, periosteum and endosteum

Question 12

Name the function and location of osteocytes

Answer 12

Sense mechanical strain
Trapped in matrix

Question 13

Name the function and location of osteoclasts

Answer 13

Born resorption
Bone surfaces and sites of old injured uneeded bone

Question 14

What is bone subjected to

Answer 14

Mechanical stress or load from external forces.
Muscle contraction, impact lonading, gravitational forces

Question 15

What can stress on the bone be

Answer 15

Compressive. Tensile.

Question 16

What is WOLFS LAW

Answer 16

bone adapts to loads under which it is placed

Question 17

Describe what happens in bone formation

Answer 17

Osteoblasts dominate
Bone becomes stronger- and eight bearing exercise
Responses to increase stress

Question 18

What does resorption . Respond to

Answer 18

Decreased stress.
Osteoclasts dominate
Bones become weaker. (Disuse, immobilisation, microgravity)

Question 19

How is bone constantly remodelled in adults

Answer 19

Older bone replaces by new bone to maintain functional properties

Question 20

How often is Cory cal and spongy bone replaces

Answer 20

C- 10 years
S- 3-4 ywars

Question 21

Describe the activation in bone remodelling

Answer 21

Hormonal or mechanical stress timulation detected by osteocytes

Question 22

Describe the resorption in bone remodelling

Answer 22

Osteoclasts release acid and enzymes to break down bone, creating howships lacunae

Question 23

Describe the reversal in bone remodelling

Answer 23

Osteoclasts die and osteoblasts precursors enter lacunae

Question 24

Describe the formation in bone remodelling

Answer 24

Osteoblasts generate new osteoid. Some osteoblasts become buried to become osteocytes

Question 25

Describe the termination/mineralisation in bone remodelling

Answer 25

Some osteoblasts die and some become osteocytes. Osteoid undergoes calcification

Question 26

How does “coupled remodelling” occur. Describe this

Answer 26

Activities of daily living produce enough stress so formation and reabsorption are in balance.

Question 27

Describe uncoupled remodelling

Answer 27

Stress is insufficient and reabsorption dominates and bone mass is loss

Question 28

Id the stress increases in modelling, how does this affect bone

Answer 28

Formation dominates, bone mass increases

Question 29

Describe the process of bone development and growth

Answer 29

1) Skelton starts as cartilage model in the womb
2) as it grows, cartilage becomes calcified in diaphysis
3) blood vessels grow in area, bringing nutrients, oxygen and new cells. Osteoblasts and osteoclasts. Osteoblasts convert calcified matrix to spongy bone
4) osteoclasts break down newly formed bone creating medullary cavity
5) new ossification centre develops at epiphysis. Step 1-4 repeat
6) epiphyseal plate develops and cartilage production here and at ends of bone matched by conversion to bone