Bones

Question 1

What is the functions of Bone

Answer 1

Provides support
acts as a lever for effect movement
protection of internal organs
calcium storage
hemopoiesis

Question 2

what are the cells of bone

Answer 2

osteoblasts , osteocytes and osteclasts

Question 3

what is the organic extracellular matrix

Answer 3

collagen type 1 , proteoglycans and glyocporitens

Question 4

what is the inorganic extracellular matrix

Answer 4

minerals - ca , na , mg , po4

Question 5

what is osteoprogenitor cells derived from

Answer 5

mesenchyme

Question 6

what is the location of osteoprogenitor cells

Answer 6

on the bone surface under the periosteum

Question 7

what is the function of the osteoblasts

Answer 7

syntehsis the organic compoents of matrix

Question 8

where is osteocytes found

Answer 8

found in cavities (lacuane) between layers lamellae of bone matrix

Question 9

what is osteoclasts

Answer 9

giant cells

Question 10

what is the function of the osteoclast

Answer 10

respoirtion and remodelling of bone tissue

Question 11

what does the unmineralzied matric eventually become

Answer 11

mineralisex bone tissue

Question 12

Bone Mineralisation - what does osteoblasts form

Answer 12

osteoid amd matrix vescile

Question 13

bone minerlisation - what does osteoid form

Answer 13

type i collagen, glycoproteins and proteoglycans

Question 14

bone minerlisation - what does matrix vesicles form

Answer 14

alkaline phosphatase

Question 15

bone mineralisation - what does type i collagen, glycoproteins and proteoglycans cause

Answer 15

increase Ca2+ concentration

Question 15

bone minerlisation - what does alkaline phosphatase increase

Answer 15

Increases PO4 concentration

Question 16

bone mineralisation - what does increase in Ca2+ and PO4 concentration cause

Answer 16

formation of CaPO4 crystals

Question 17

bone mineralisation - what does calcium phosphate crystal

Answer 17

attract water molecules and aggreate into the masses of hydroxyapatite crystals

Question 18

what do osteoblasts also release

Answer 18

very small membrane enclosed matrix vesicles which contain alkaline phosphate and other enzymes

Question 19

what are some osteoid components

Answer 19

osteocalcine, binds calcium ions with high affinity

Question 20

what does osteocytes derived from

Answer 20

oasteoblasts

Question 21

what are osteocytes not capable of

Answer 21

not capable of mitosis

Question 22

what happens to the number of osteocytes with age

Answer 22

decrease with aging and can caclify as well

Question 23

what are osteocytes canliculi

Answer 23

thin cytoplasmic process

Question 24

what is the function canaliculi

Answer 24

transport materials to the adjacent osteocytes

Question 25

what is osteclasts in respotions bays

Answer 25

osteocytes lie within depression or crytps in the matrix when undergoing resportion

Question 26

what is cortical bone

Answer 26

dense areas without caities make up the shaft / diapghysis

Question 27

what is cancellous

Answer 27

numerous interconnecting cavities or a fine meshwork and occupies the epiphysis

Question 28

what is periosteum

Answer 28

dense connective tissue sheath

Question 29

what are the two layers of periosteum

Answer 29

inner cellular layer what is the outer cellular layer

Question 30

what is the inner cellular layer

Answer 30

osteoprogenitor cells osteoblasts

Question 31

what does endosteum line

Answer 31

large intnerla marrow cavities of bone

Question 32

how many layers of endoesteum

Answer 32

single layer of connective tissue

Question 33

what does endosteum contain

Answer 33

flattened osteoprogenitor cells and osteoblasts

Question 34

what is a osteon

Answer 34

cortical bone has a compact arrangement of bone

Question 35

where do the blood vessels that penetrate

Answer 35

through the periosteum into the compact bone to occupy the central canal of these osteon

Question 36

what is the external circumferential lamellae

Answer 36

outermost arrangement of the lamellae

Question 37

what is haverisan canal

Answer 37

lamellae circular pattern around the blood vessels occupy a canal

Question 38

what is Walkmans canal

Answer 38

perforating vessels

Question 39

how many canaliculi

Answer 39

10 chains via gap junctions

Question 40

what is outer circumferential lamellae

Answer 40

outer layers of bone are organised in lamellae that run around the bone

Question 41

what is woven bone (primary bone)

Answer 41

irregular arrangment of collagen fibres lower mineral content

Question 42

what is lamellar (secondary bone)

Answer 42

regular layered arrangement of collagen fibres higher mineral content

Question 43

what happens in compact bone bone remodelling

Answer 43

old oesteon are resorbs and produce new ones

Question 44

what does resorption involve

Answer 44

osteoclasts remove old bone in tunnel like cavities

Question 45

what are the cutting bone invaded by

Answer 45

osteoprogenitor cells and sourpting loops of blood cappliers which are derived from the endosteum or peirostem

Question 46

what cuts lines in the tunnels

Answer 46

osteoblasts

Question 47

how are osteoid serected

Answer 47

cylic manner

Question 48

what does cutting bone form

Answer 48

concentric lemaule of bone with trapped osteocytes in between and will continue to lay don boney tissue in the space

Question 49

what is cement lines

Answer 49

visible surrounding an osteon

Question 50

where is cement lines found

Answer 50

where constant remodelling of bone prdocues these lines so

Question 51

what does remodelling causes

Answer 51

new osteons to be laid down over old ones

Question 52

what are the areas present between osteon

Answer 52

intersisital lamellae

Question 53

cartilage vs bone - permeability

Answer 53

cartilage - permeable bone - non preamble

Question 54

cartilage vs bone ability

Answer 54

cartilage - deformable bone - rigid

Question 55

cartilage vs bone - growth

Answer 55

bone - apposition only cartilage - appositional and intersitial

Question 56

cartilage vs bone - cells nourishment

Answer 56

cartilage - cells nourished by diffusion through matrix bone - cells within the bone must be nourished by blood vessels that pervade the matrix