Tissues Structure And Function (Ob)

Front 1

Functions of conective tissue

Back 1

Mechanical (supporting matrix, force transmitter ie. tendons)
Metabolic (route of exchange between blood and tissues, fat storage)
defence and repair (Fat - cushioning ie. heel, macrophages and mast cells involved in inflamm)
Growth and morphogenesis (plays an important in development and maintainance of all tissues

Front 2

ECM make-up

Back 2

Cells
Ground substance (anything non-cellular)

Front 3

Define:connective tissues

Back 3

Any tissue where ground substance makes up more quantity than cellular material.

Front 4

Cells of connective tissue

Back 4

1.Mast cells
2.Macrophages - phagocytose invading organisms and dead cells. Also release local anti-inflammatories (cytokines) to keep inflamation local and prevent spread.
3.Fibroblasts - secrete matrix and growth factors
4.Leukocytes

Front 5

Matrix/ground substance contents

Back 5

Glycosaminoglycans
Proteoglycans
Glycoproteins

Front 6

Glycosaminoglycans

Back 6

(ie. hyaluronic acid) long linear carbohydrates - extended conformation and occupy large volumes relative to their mass.
High negative charge - therefore attract a lot of water and form hydrated gels - contributes to viscosity and compressive pressure absorbing qualities of connective tissue.
Pore size of the gels determined by GAGs present - therefore selective diffusion.

Front 7

Proteoglycans

Back 7

Formed by cov linkage of GAGs to a core protein or glycoprotein.
Apart from structural role - also has role in activating and regulating the function of signalling molecules ie. FGF - activated by binding to a proteoglycan

Front 8

Glycoproteins

Back 8

Smaller proteins that have been glycosylated ie.laminin. Provide a means by which cells can attach to, and move through, a matrix.

Front 9

Fibres of Connective tissue

Back 9

Mainly collagen - bone cartilage, clood vessels heart valves etc.
Type 1, 2 (cartilage) and 3 very similar - 3 helices wrapped around one another in superhelix.
Type 4 in basal lamina forms sheets.
Fibrillar collagen - 1 in 3 reesidues = glycine - critical to triple helix formation.

Front 10

Osteogenesis imperfecta

Back 10

Brittle bone disease
One Glycine point mutation switches
Unable therefore to form triple helix structur - vital to fibrillar shape and function.

Front 11

Marfans

Back 11

Mutation of fibrillin - a component of elastic fibre - loss of integrity of fibres - tendency of aorta to rupture

Front 12

Scurvy

Back 12

Hydroylation of Pro residues in collagen important to form tight links between the strands - Vit C required
If no Vit C - reduced linking - fragility of skin, blood vessels and tendons - and loose teeth

Front 13

Atherosclerosis

Back 13

Elastic fibres of blood vessel lost and replaced with collagen - tendency to dilate and possibly rupture

Front 14

3 types of cartilage

Back 14

Hyaline (template of bones, joints articular surface)
Fibro (intravertebral discs - type 1 collagen too)
Elastic (external ear)

Front 15

Appositional growth

Back 15

New cartilage added to surface of older cartilage by Chondroblasts from deep layer of perichondrium

Front 16

Interstitial growth

Back 16

Newer cartilage formed within older cartilage by chondrocytes that divide (and also produce new matrix)

Front 17

Bone - with epiphyseal plate - on which side does new cartilage form on - which side does it become bone?

Back 17

Ok this is end of bone (_) underscore is growth plate - new cartilage formed on top side, cartilage becomes bone on bottom side!

Resting zone
Proliferative zone
Hypertrophic zone
Ossification zone

Front 18

Bone - functions

Back 18

Calcium and phosphate reserve
Support
Mobility
Protection
Bone marrow

Front 19

Intramembranous ossification

Back 19

(Clavicle, skull)
Osteogenic progenitor cells differentiate in mesenchyme to form osteoblasts - secrete matrix.
Some become embedded and become osteocytes.

Differentiation into osteoblasts - initial formation of bone spicule

Spicules enlarge and invaded by blood vessels

Fusion of spicules to form plates of bone

Start of osteoclastic remodelling

Front 20

Osteoarthritis

Back 20

Breakdown of articular cartilage
Breakdown products can also cause local inflamm at the joint.

Front 21

Cells of cartilage

Back 21

Chondroblasts (stem cells) secrete ECM of fibres and glycoproteins giving appositional (layer upon layer) and interstitial (internal) growth.
Mature Chondroblasts = chondrocytes - become embedded in lacunae

Front 22

Osteoblasts, clasts and cytes

Back 22

Blasts - secrete matrix molecules, therefore form new bone.
Clasts - breakdown bone for remodelling by acid and proteolytic enzyme secretion.
Cytes - embedded in bone - respond mechanical and other stimuli to initiate other events leading to new bone formation.

Front 23

Perichondrium

Back 23

Layer of dense irregular connective tissue.
Outer layer contains fibroblasts secreting collagen fibres
Inner layer containing undifferentiated stem cells, which can become Chondroblasts (which then become -cytes when embedded in lacunae) or Chondrocytes.
Becomes the periosteum

Front 24

Periosteum

Back 24

Outer fibrous layer
Innerlayer is osteogenic - can differentiate into Osteoblasts.

Front 25

Endochondral ossification.

Back 25

see notes

Front 26

Collagen contributes...
Hydroxyapatite contributes....

Back 26

Collagen - tensile strength E=denature - brittle

Hydroxyapatite - compressive E=demineralised - can fold around!

Front 27

Neutrophils

Back 27

55%
Granulocyte
Multi-lobed nucleus
Small granules
Phagocytose bacteria and fungi

Front 28

Eosinophils

Back 28

5%
Granulocyte
Bi-lobed nucleus
Large Pink granules
Kill metazoal parasites

Front 29

Basophils

Back 29

1%
Granulocyte
Large Blue granules
Release histamine
Bilobed nucleus

Front 30

Monocytes

Back 30

5%
Agranular
Kidney shaped nucleus
Develop into macrophages which ; phagocytose and kills organisms
Removes tissue debris
Remodels tissue

Front 31

Small lymphocyte

Back 31

30%
Round nucleus - clumped chromatin
Quiescent, not dividing, awaiting activation by antigen
Circulates blood looking for antigen, when finds-initiates immune response.

Front 32

Large lymphocyte

Back 32

1-5%
bit bigger (12-16um)
Kidney shaped nucleus
Activated, dividing, developing to effector cells

Front 33

Cytokines

Back 33

Intercellular communicating molecules
Interleukins are a sub division of these

Front 34

Innate and adaptive response

Back 34

Innate - everything except lymphocytes - not more effective after previous infection