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BDS1 - BAMS - Histology > Bone and cartilage > Flashcards

Flashcards in Bone and cartilage Deck (50)
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1

What is bone

a mineralized connective tissue

2

What is the function of bone

structural support
protection
locomotion
mineral reservoir
blood cell production

3

What is the function of cartilage

locomotion - smooth surface at bone ends
structural support
template for new bone formation

4

What are the two different anatomical structure of bones

flat or long

5

Describe flat bones

thin and flat
sometimes have a slight curve
serve as a point of attachment for muscles or protection for your internal organs

6

Describe long bones

longer than they are wide
function to support the weight of the body and facilitates movement

7

What is periosteum

Connective tissue that surrounds the outer surface except the articular cartilage

8

What is cortical/compact bone

outer layer
It forms a protective layer around internal cavity as it is highly calcified and strong

9

What is cancellous/trabecular/spongy

Inner layer of interconnected trabeculae
Found at the end of long bones

10

What is red bone marrow

Red blood cell production

11

What is yellow bone marrow

store fat i.e energy storage

12

What is the endosteum

inner membrane connective tissue lining the inner surface of the bone and separates the bone from the marrow

13

What are the 3 components of bone

ECM (ground substance and fibers)
cells

14

What does the ground substance consist of

chrondriotin sulphate
hyaluronic acid

15

what does the fibers consist of

type I collagen

16

What are the cells

osteoblasts
osteocytes
osteoclasts

17

What is the extracellular matrix in bone

made up of organic matrix (30%) and hydroxyapatite (70%)
Before the ECM is calcified it is called osteoid

18

What are osteogenic/osteoprogenitor cells

bone cell precursor
gives rise to osteoblasts
'stem' cells of bone and so can divide

19

What are osteoblasts

they synthesise and secrete bone tissue (osteoid) and mediate its mineralization
They give rise to osteocytes

20

What are osteocytes

They maintain mineralized bone tissue

21

How are osteocytes formed

osteoblasts are surrounded by the growing bone matrix and as the material calcifies, the cell is trapped in a space called lacuna and are thus entrapped becoming an osteocyte

22

What is an osteoclast

They resorb bone
They are derived from monocyte/macrophage lineage (immune cells)

23

What are the steps in the mineralization of bone

1. osteoblasts secrete osteoid
2. osteoblasts secrete collagen and matrix vesicles
3. Matrix vesicles direct the deposition of hydroxyapatite crystals
4. As osteoid is mineralized, osteoblasts get trapped as osteocytes in lacunae
5. A new osteon or haversian system is formed leaving behind concentric lamellae, interstitial lamella and circumferential lamellae

24

What are the two layers of periosteum

outer layer - dense, irregular fibrous tissue
inner cellular layer - adjacent to the bone surface - contains osteoblasts and osteogenic stem cells

25

What is the histological structure of cortical bone

composed of osteon
each osteon is composed of layers of lamellae
central canal of each osteon contains nerves, capillaries and lymphatics

26

What are the steps to bone remodeling

1. osteoclasts resorb a wide channel
2. nerves, capillaries and lymphatics grow into the channel
3. osteoblasts line the channel and lay down osteoid
4. as osteoid is mineralized, osteoblasts get trapped as osteocytes
5. concentric lamellae
6. interstitial lamellae
7. circumferential lamellae

27

What are the external factors that affect bone remodeling

hormonal
neuronal
immunological

28

What is the histological structure of trabecular bone

contains lamellar bone
lattice like network of rods called trabeculae
orientated to provide maximum strength for minimum mass
spaces between trabeculae occupied by red and yellow marrow
Lined externally but endosteum

29

What are the 3 types of cartilage

hyaline
fibro
elastic

30

What is cartilage

avascular, flexible, connective tissue that provides strength and cushioning