Connective (support tissue) and extracellular matrix

Question 1

what do connective tissues provide?

Answer 1

general structure
physical and metabolic suport for more specialised tissues
mechanical strength
fill spaces in the body

Question 2

what are the general three properties of connective tissue?

Answer 2

Tensile strength
Elasticity
Volume

Question 3

what provides tensile strength in connective tissue?

Answer 3

collagen

Question 4

what provides elasticity in connective tissue?

Answer 4

elastin

Question 5

what provides volume in connective tissue?

Answer 5

ground substance

Question 6

what is ground substance?

Answer 6

various molecules secreted by the support tissues within connective tissue

Question 7

what are the classifications of connective tissue?

Answer 7

connective tissue proper
cartilage
bone
blood

Question 8

what are the two types of connective tissue proper?

Answer 8

loose and dense

Question 9

what are the three types of loose connective tissue proper?

Answer 9

Areolar
Reticular
Adipose

Question 10

what are the features of loose connective tissue proper?

Answer 10

open, loose structure

Question 11

what are the features of areola loose connective tissue proper?

Answer 11

strong yet cushioning
Underlies epithelium , and forms the lamina propria

Question 12

what are the features of reticular loose connective tissue proper?

Answer 12

reticular fibres (supportive mesh)
Supports organs

Question 13

what are the features of adipose loose connective tissue proper?

Answer 13

full of adipocytes
white- stores energy
Brown- thermoregulation

Question 14

what are the two types of dense connective tissue proper?

Answer 14

regular
irregular

Question 15

what classified dense connective tissue proper?

Answer 15

greater proportion of fibres
very little ground substance

Question 16

what are the features of regular dense connective tissue proper?

Answer 16

parallel fibres (mainly type 1 collagen)
ligaments and tendons

Question 17

what are the features of irregular dense connective tissue proper?

Answer 17

non-parallel fibres
in the dermis

Question 18

what are the types of connective tissue in the dermis?

Answer 18

loose in the papillary dermis
dense in the reticular dermis

Question 19

what are the three types of cartilage?

Answer 19

hyaline
fibrocartilage
elastic

Question 20

what is hyaline cartilage?

Answer 20

smooth, translucent
few collagen fibres
Ends of bones, tracheal rings

Question 21

what is fibrocartilage?

Answer 21

many collagne fibres

e.g. catilaginouse joints, menisci of knee joint

Question 22

at is elastic cartilage?

Answer 22

elastin and collagen fibres

in the ear

Question 23

what are the features of bone connective tissue?

Answer 23

collagen containing extracellular matrix, but it becomes calcified

-compact bone
-cancellous bone, forming the trabeculae
the layout depends on the stress/weight bearing nature of the bone

Question 24

what are the key components of connective tissue?

Answer 24

cells and extracellular matrix

Question 25

what determines the properties of a tissue?

Answer 25

the constituents of the ECM

Question 26

what are support cells?

Answer 26

derived from embryological tissue mesenchyme produce the extracellular matrix components

Question 27

what are the support cells of the connective tissue proper?

Answer 27

fibroblasts

Question 28

what are the support cells of cartilage?

Answer 28

chondroblasts

Question 29

what are the support cells of bone (osseous)?

Answer 29

osteoblast, to osteocyte

Question 30

what is the general function of connective tissue proper?

Answer 30

acts as a binding tissue; resists mechanical stress, particularly tension

Question 31

what are the matrix components if connective tissue proper?

Answer 31

Gel-like ground substance; all three fibre types

Question 32

what are the matric components of cartilage?

Answer 32

Gel-like ground substance; collagen fibers, elastin fibres in some

Question 33

what is the general function of cartilage?

Answer 33

resists compression and supports body structures

Question 34

what are the matrix components of bone?

Answer 34

Gel-like ground substance hardened with calcium salts: collagen fibres

Question 35

what is the general function of bone?

Answer 35

Rigidness that resists compression and tension; support

Question 36

what makes up the extra cellular matrix?

Answer 36

ground substance fibrillar proteins adhesion proteins

Question 37

what makes up the ground substance in ECM?

Answer 37

glycosaminoglycans (GAGs)- very long unbranching polysaccharides Proteoglycans- proteins that covalently bond to GAGs

Question 38

what is the function of ground substance in ECM?

Answer 38

ground substance binds to water, salts, collagen proteins, other molecules to make a massive matrix structure

Question 39

what is the function of fibrillar proteins in the ECM?

Answer 39

fibres provide strength or elasticity

Question 40

what is the function of adhesion proteins in the ECM?

Answer 40

link fibres, ground substance and cells together

Question 41

what are glycosaminoglycans (GAGs)?

Answer 41

-long unbranched polysaccharide chains -hyaluronic acid (hyaluronate) most common GAG -long linear molecules of two repeating sugar molecules other GAGs attach via hyaluronic acid via core proteins (forming proteoglycans)

Question 42

what do proteoglycans and glycosaminoglycans interact with?q

Answer 42

-each other -with water and salts -collagen -and other fibres and molecules

Question 43

what is the function of proteoglycans and glycosaminoglycans?

Answer 43

-form the ground substance -volume and compression resistance

Question 44

what are the two fibrillar proteins?

Answer 44

collagen Elastin

Question 45

what is the function of fibrillar proteins?

Answer 45

add strength/elasticity to tissue

Question 46

What is the function of collagen?

Answer 46

forms fibrils, fibres and sheets, gives tensile strength Many types

Question 47

what is the function of elastin?

Answer 47

forms fibres or sheets, allows stretching and elastic recoil

Question 48

what is collagen?

Answer 48

most abundant protein in the human body found in most support tissues secreted by fibroblasts stains pink in H and E

Question 49

what is the structure of collagen?

Answer 49

collagen is a series of twisted protein fibres fibres are banded under the electron microscope due to the different overlap between the triple helices

Question 50

what is the function of Type 1 collagen?

Answer 50

~90% of collagen in body. Makes up ligaments, tendons, bone, skin

Question 51

what is the function of type 2 collagen?

Answer 51

cartilage

Question 52

what is the function of type 3 collagen?

Answer 52

reticular tissue (forms reticular fibres)

Question 53

what is the function of type 4 collagen?

Answer 53

basement membrane

Question 54

what are some diseases caused by collagen defects?

Answer 54

Osteogenesis Imperfecta Ehlers-Danlos syndromes

Question 55

what is elastin?

Answer 55

Produced by fibroblasts Abundant in blood vessels, skin, lungs, elastic cartilage

Question 56

what is the structure of elastin?

Answer 56

Elastin protein comprised of short-segments Covalently bound to each other, to allow stretching and relaxation

Question 57

what is the function of adhesion proteins (glycoproteins)?

Answer 57

Mediate interactions between cell cytoskeleton and extracellular matrix

Question 58

what are two adhesion proteins?

Answer 58

fibronectin Laminin

Question 59

what is fibronectin?

Answer 59

-dimeric glycoprotein -binds collagen, proteoglycans, and cells -binds collagen to integrins on cell surface

Question 60

what is laminin?

Answer 60

-binds multiple components of the ECM -form sheets that make up basement membrane -binds cells to basement membranes (binds to integrins)

Question 61

what are the adhesion mechanisms of the cell matrix?

Answer 61

junctions between cells and the extracellular matrix are important in maintaining structural integrity

Question 62

What are focal adhesions?

Answer 62

bind cells to the extra cellular matrix

Question 63

what are hemidesmosomes?

Answer 63

attach epithelial cells to basement membrane

Question 64

what protein is important in both hemidesmosomes and focal adhesions?

Answer 64

integrin proteins

Question 65

how do cells anchor to the ECM?

Answer 65

Matrix- GAGs and proteoglycans Structural fibres- collagen and elastin Adhesive glycoproteins- fibronectin and laminin Transmembrane receptors- integrin

Question 66

what is the role of focal adhesions?

Answer 66

Attach cells to the ECM -integrin proteins on both sides of the lipid bilayer

Question 67

how do support cells bind to the ECM?

Answer 67

via focal adhesions

Question 68

what are hemidesmosomes?

Answer 68

Modified desmosomes Basal surface of cell Anchor to basement membrane Bind to cytokeratin Main transmembrane protein (integrns)

Question 69

how to epithelial cells bind to the ECM?

Answer 69

via hemidesmosomes