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Flashcards in phase 1 week 5 Deck (90):
1

What types of bone are there?

long bone
short bone
irregular bone
flat bone
sesamoid bone

2

give an example of a long bone

humerus

3

give an example of a short bone

carpal bone

4

give an example of an irregular bone

vertebra

5

give an example of a flat bone

sternum

6

give an example of a sesamoid bone

patella

7

Describe the diaphysis of a bone

main shaft-like portion
hollow and cylindrical shape with thick compact bone on the outside
strong but not too heavy

8

describe the epiphysis of a bone

both ends of a long bone
bulbous shape which provides space for muscle attachment
red marrow fills the spaces of cancellous bone

9

describe the metaphysis of a bone

the region where the epiphysis and diaphysis meet

10

describe the periosteum

dense, white, fibrous membrane
covers bone except for joint surfaces
periosteum fibres penetrate the underlying bone
tendon fibres and periosteum fibres interlace to attach muscle to bone
contains bone remodelling cells and blood vessels

11

Describe articular cartilage

thin layer of hyaline cartilage that covers the articular surfaces of bones
resilient material that cushions jolts and blows

12

describe the medullary cavity

hollow space in diaphysis of long bone.
in adults filled with yellow marrow

13

Describe the endosteum

thin, fibrous membrane that lines the medullary cavities and spaces of cancellous bone
contains bone cells and their precursors

14

Describe compact bone

cylindrical-shaped osteons or haversian systems
each osteon surrounds a canal which runs longitudinally through the bone

15

Describe cancellous bone

no osteons
tiny needle-like branches called trabeculae
nutrients and waste products diffuse via tiny canaliculi that extend to the surface of the very thin bony branches

16

Describe osteoclasts

large cells with many nuclei
share lineage with blood cells (macrophages)
Precursors circulate in blood and bone marrow
When RANK-ligand (from osteoblasts) binds with RANK receptors - mature osteoclast form from fusion of progenitor cells
osteoclasts resorb bone
release acids and enzymes
then undergo apoptosis

17

What is OPG?

osteoprotogerin
binds to RANK-ligand so can regulate osteoclast activity

18

Describe osteoblasts

cuboidal and columnar shape with central nucleus
found on bone surface
from mesenchymal stem cells
osteoblasts make proteins to form the organic matrix of the bone and regulate mineralisation
Receptors for vitamin D, oestrogen and parathyroid hormone
secrete RANK-ligand to activate osteoclasts
can differentiate into osteocytes, lining cells or undergo apoptosis

19

Describe osteocytes

long branches that allow them to contact each other and the lining cells at the bone surface
sense mechanical strain
secrete growth factors to activate lining cells or osteoblasts

20

Describe lining cells

flat and pancake-shaped
responsible for immediate release of calcium
Protect bone from chemicals that dissolve crystals
receptors for hormoes and factors that effect bone remodelling

21

What are BMPs?

bone morphogenetic proteins
produced in bone or bone marrow
bind to BMP receptors on mesenchymal cells
cells produce cbfa1 - a transcription factor
cells mature into mature osteoblasts

22

Describe IGFs in regards to bone

Insulin-like growth factors
produced by osteoblastic cells in response to parathyroid hormone, oestrogen or BMPs
released from matrix during bone remodelling and stimulate osteoblastic cell replication

23

Describe RANK-ligand

a cytokine that is produced in response to systemic hormones such as 1,25dihydroxyvitaminD3 and other cytokines such as IL6
Induces osteoclast development

24

What hormones increase bone resorption?

parathyroid hormone
glucocorticoids
thyroid hormone
vitamin D metabolites

25

What hormones decrease bone resorption

calcitonin
gonadal steroids

26

what hormones increase bone formation?

growth hormone
vitamin D metabolites
gonodal steroids

27

What hormones decrease bone formation?

glucocorticoids

28

what are the main type of inorganic salts found in bone?

hydroxyapatite crytals

29

What is the organic matric of bone composed of?

collagenous fibres and "ground substance"

30

name features of a synovial joint

articular cartilage
synovial cavity
synovial membrane
joint capsule

31

what are the two names for the three kinds of joints?

synarthroses (fibrous)
ampiarthroses (cartilaginous)
diarthrosis (synovial)

32

Describe synarthrosis movement

immovable

33

describe ampiarthoses movement

slightly moverable

34

Describe diarthrosis movement

freely moveable

35

What types of fibrous joints are there?

Syndesmoses
sutures
gomphoses

36

What are syndesmoses joints?

e.g. distal end of radius and ulna
ligament connects bones

37

What are sutures?

only found in the skull
interlocking teeth-like projections

38

What are gomphoses?

found at the root of the teeth
periodontal membrane

39

What type of cartilaginous joints are there?

synchondrosis
symphyses

40

What are synchondroses?

e.g. between first rib and sternum
hyaline cartilage between articulating surfaces

41

What are symphyses?

e.g. pubic symphysis
fibrocartilage disk

42

What kinds of synovial joints are there?

uniaxial - hinge, pivot
biaxial - saddle, condyloid
multiaxial - ball and socket, gliding

43

Describe the uniaxial joints

hinge - e.g. elbow, flexion and extension
pivot e.g. between C1 and C2, rotation

44

Describe the biaxial joints

saddle - e.g thumb joint. flexion, extension, adduction and abduction
condyloid - between radius and carpal bones - flexion, extension, adduction and abduction

45

Describe the multi axial joints

ball and socket - e.g. shoulder - wide range
gliding - e.g between articulating facets of vertebrae. Gliding

46

what are the three types of cartilage?

hyaline cartilage
elastic cartilage
fibrocartilage

47

How do chondrocytes get their nutrients?

only through diffusion from the periosteum or synovial fluid - cartilage is avascular unlike bone

48

Describe hyaline cartilage

most common
both collagen and elastic fibres
articular surfaces of bones, tracheal rings, bronchi of lungs, tip of the nose

49

Describe elastic cartilage

large numbers of elastic fibres
gives form to external ear, epiglottis, eustachian tubes

50

Describe fibrocartialge

small quantities of matrix and abundant fibrous elements
strong, rigid
pubis symphyses, IV disks, near site of attachment of some large tendons to bones

51

what are the main changes seen in an osteoarthritic joint?

thickened capsule
cyst formation and sclerosis of subchondral bone
fibrillated cartilage
osteophytic lipping
synovial hypertrophy
altered contour of bone

52

What causes damage to cartilage in OA?

decreases in water content, proteoglycan synthesis, collagen cross linking, size of GAGs and hyaluronic acid
traumatic damage

53

What is osteoarthritis?

progressive disorder of the joints caused by gradual loss of cartilage and resulting in the development of bony spurs and cysts and the margin of the joint

54

What are the causes of OA?

primary - degenerative
secondary - trauma, hip dysplasia, infection, diabetes

55

who is most affected by OA?

women over 45

56

What is seen in an X-ray of an OA joint?

joint space narrowing
osteophytes
subchondral bone sclerosis
cyst formation

57

What is ECM?

extracellular matrix
a complex network of proteins and polysaccharides
secreted locally
provides structural, adhesive and biochemical signalling support

58

What makes up ECM?

fibres - collagen and elastin
ground substance - proteoglycans, glycosaminoglycans, glycoproteins

59

What are the functions of ECM?

mechanical and structural support
tensile strength
determines cellular movment

60

what are the five classes of macromolecules found in ECM?

collagens
elastin
proteoglycans
glycosaminoglycans
other glycoproteins

61

where is type I collagen found?

dermis, tendons, ligaments, bones

62

where is type II collagen found?

hyaline cartilage

63

Where is type III collagen found?

liver, bone marrow, lymphoid organs

64

Where is type IV collagen found?

basement membrane

65

Where is type V collagen found?

linker to basement membrane

66

Describe GAGs

also called mucopolysaccharides
chains of repeating disaccharide units
carbohydrate component of proteoglycans

67

What GAG is found in the synovial fluid?

hyaluronic acid

68

What GAGs are found in cartilage?

chondroitin sulphate and keratan sulphate

69

What GAG is found in the basement membrane?

Heparin sulphate

70

what makes aggrecan and where is it found?

chondroitin sulphate and keratan sulphate
cartilage

71

What is perlecan made from and where is it found?

heparan sulphate
basement membrane

72

What is syndecan made from and where is it found?

chondroitin sulphate and keratan sulphate
cartialge

73

What is decorin made from and where is it found?

chondroitin sulphate and dermatan sulphate
wide spread

74

Give examples of 5 glycoproteins

fibrillar
fibronectin
laminin
entactin
tenascin

75

What does fibrillin do?

controls deposition and orientation of elastins

76

what does fibronectin do?

linker role in BM

77

What does laminin do?

primary organiser in BM

78

What does entactin do?

linker role in BM

79

What does tenascin do?

linker role in connective tissue

80

How is collagen made?

synthesised as pro collagen
post-translational modification - glycosylation and hydroxylation
assembled as triple helix

81

How is elastin made?

synthesised as tropo elastin
post-translational modification - hydroxylation
assembled in fibrillin scaffold, cross-linked fibres

82

What are the three layers of the basement membrane?

lamina lucida
lamina densa
lamina fibroreticularis

83

what is the basement membrane composed of?

collagen
laminin
perlecan
entactan

84

what are the functions of the basement membrane?

support
binding to underlying connective tissues
mediates signalling
determines cell polarity
permits flow of nutrients
path for cell migration
barrier to downward growth

85

Give examples of disorders of BM

cancer - epithelial tumours malignant when breach BM
Diabetes - thickening of BM of glomerulus alters function
epidermolysis bullosa - attachment of epidermis to BM
Good pastures syndrome - autoantibodies to collagen IV destroy BM in lung and glomerulus

86

A condition caused by problem in elastin

supravalvular aortic stenosis

87

A condition causes by a problem with fibrillin I

Marstan syndrome

88

A condition caused by a problem with collagen

etlers danlos syndrome

89

a condition caused by problem in keratan sulphate

macular corneal dystrophy

90

a condition caused by problem with perlecan

Silverman-Handermaker type of dyssegmental dysplasia (DDSH) lethal dwarfism