Connective Tissue

Question 1

what are connective tissue cells derived from?

Answer 1

• undifferentiated mesenchymal cells

- can derive from haematopoetic stem cell line

Question 2

describe the structure of connective tissue cells

Answer 2

• scaffold of extracellular fibres

- jelly-like matrix

Question 3

what do connective tissue cells contain?

Answer 3

• collagen

- elastin

Question 4

what makes connective tissues amorphous?

Answer 4

• high molecular weight
• strongly hydrophilic
• negatively charged

Question 5

what cells are in connective tissues?

Answer 5

• fibroblasts

- adipose cells

Question 6

what are the visible fibres in connective tissues?

Answer 6

• collagen
• elastin
• reticulin

Question 7

what does the ground substance (hydrophilic jelly) of connective tissues contain?

Answer 7

• proteoglycans
• glycosaminoglycans
• invisible fibres (e.g. laminin, fibronectin)

Question 8

what does the ground substance (hydrophilic jelly) of connective tissues contain?

Answer 8

• proteoglycans
• glycosaminoglycans
• invisible fibres (e.g. laminin, fibronectin)

Question 9

what is fibrous connective tissue?

Answer 9

contains large numbers of fibres such as collagen, elastin or reticulin

Question 10

what is fatty connective tissue?

Answer 10

contains mainly fat cells with intervening blood vessels (particularly capillaries)

Question 11

what is hard connective tissue?

Answer 11

various forms of bone

Question 12

what is soft connective tissue?

Answer 12

• flexible and gel-like

- interspersed between major tissue elements

Question 13

what are the types of soft connective tissue?

Answer 13

• fibrous

- fatty

Question 14

what are the types of fibrous connective tissue?

Answer 14

• loose

- dense

Question 15

what are the types of fatty connective tissue?

Answer 15

• white

- brown

Question 16

what are the types of hard connective tissue?

Answer 16

• cartilage

- bone

Question 17

describe the structure of collagen

Answer 17

• individual collagen fibrils consisting of overlapping linear strands of tropocollagen

Question 18

what is tropocollagen?

Answer 18

3 linear polypeptide chains wound together in alpha helix

Question 19

what synthesises tropocollagen?

Answer 19

fibroblasts

Question 20

where is type I collagen?

Answer 20

• skin
• tendons
• ligaments

Question 21

where is type II collagen?

Answer 21

cartilage

Question 22

where is type III collagen?

Answer 22

• liver
• bone marrow
• spleen
• kidney
• lymph nodes

Question 23

where is type IV collagen?

Answer 23

basement membranes

Question 24

where is type V collagen?

Answer 24

placenta

Question 25

does collagen stain with H&E?

Answer 25

yes

Question 26

how is collagen identified histologically?

Answer 26

- variable thickness and length - often run in bundles - no nuclei

Question 27

what is reticulin?

Answer 27

type III collagen

Question 28

what is the function of reticulin?

Answer 28

supporting scaffold in organs

Question 29

how is reticulin identified histologically?

Answer 29

- forms branched fibres instead of linear | - not visible on H&E (silver)

Question 30

what is the histological difference between loose and dense connective tissue?

Answer 30

dense: - closer spaced and thicker collagen ribres - may be irregular

Question 31

what are the histological similarities between loose and dense connective tissue?

Answer 31

- fibroblasts | - unstained ground substance between fibroblasts

Question 32

what does elastic tissue contain?

Answer 32

- fine fibres | - sheets of elastin

Question 33

what is elastin produced by?

Answer 33

fibroblasts

Question 34

does elastin stain on H&E?

Answer 34

yes | - pink

Question 35

what is the histological difference between elastin and muscle cells/collagen?

Answer 35

- stains more deeply | - can produce glassy appearance

Question 36

what is the histological difference between white and brown adipose tissue?

Answer 36

white: single fat globule in each cell brown: multiple globules of fat in each cell

Question 37

what is the functional difference between white and brown adipose tissue?

Answer 37

white: insulation, shock absorber brown: generates heat (thermoregulation)

Question 38

where is brown adipose tissue found?

Answer 38

across shoulders and down back of newborns

Question 39

describe the structure of cartilage

Answer 39

- dense glycosaminoglycan-rich matrix containing variable amounts of collagen and elastic tissue - surrounded by perichondrium

Question 40

what is perichondrium?

Answer 40

fibrocollaginous capsule

Question 41

what are the properties of cartilage?

Answer 41

- flexible - compressible - hard-wearing

Question 42

where are chondroblasts found and what do they mature into?

Answer 42

- matrix of cartilage | - chondrocytes

Question 43

what does the perichondrium contain?

Answer 43

undifferentiated progenitor cells capable of differentiating into chondroblasts

Question 44

what is found in the extracellular matrix of cartilage?

Answer 44

- glycosaminoglycans | - proteoglycans

Question 45

give 2 examples of extracellular fibres

Answer 45

- collagen | - elastin

Question 46

does cartilage have its own blood supply?

Answer 46

no

Question 47

what are the main types of cartilage?

Answer 47

- hyaline - elastic - fibrous

Question 48

where is hyaline cartilage found?

Answer 48

- synovial joints - articular surfaces - 'rings' of trachea - cartilages of larynx

Question 49

does hyaline cartilage stain on H&E?

Answer 49

very poorly

Question 50

where is elastic cartilage found?

Answer 50

- pinna of the ear | - epiglottis

Question 51

what is the structure of elastic cartilage?

Answer 51

irregularly arranged visible fibres of elastin in matrix

Question 52

what is the structure of hyaline cartilage?

Answer 52

- GAG-rich matrix that appears glassy | - fine fibrils of collagen and elastin

Question 53

is elastic cartilage visible on H&E?

Answer 53

yes | - more visible under silver stain (highlights elastic fibres)

Question 54

where is fibrous cartilage found?

Answer 54

- annulus fibrosus - pubic symphysis - inter-vertebral discs

Question 55

what is the structure of fibrous cartilage?

Answer 55

visible collagen fibres (often in distinct bands) in matrix

Question 56

what is synovium?

Answer 56

connective tissue lining the inside of a synovial joint capsule

Question 57

how many layers of synovial cells is typically in synovium?

Answer 57

1-4

Question 58

what are type A synovial cells?

Answer 58

phagocytes

Question 59

what are type B synovial cells?

Answer 59

- rich in RER | - secrete synovial fluid

Question 60

what shape are synovial cells?

Answer 60

variable | - squamous to cuboidal

Question 61

what are the types of muscle?

Answer 61

- visceral (smooth) - voluntary (skeletal) - cardiac

Question 62

where is visceral muscle found?

Answer 62

- arterial walls - intestinal walls - airways of lungs

Question 63

where is skeletal muscle found?

Answer 63

- skeletal muscles - larynx - diaphragm

Question 64

where is cardiac muscle found?

Answer 64

- heart | - base of great vessels

Question 65

what are other contractile cells?

Answer 65

- pericytes - myo-fibroblasts - myo-epithelial cells

Question 66

where are pericytes found?

Answer 66

alongside some small blood vessels (e.g. veins, venules)

Question 67

what is the function of myo-fibroblasts?

Answer 67

involved in scar formation

Question 68

what is the function of myo-epithelial cells?

Answer 68

- assist expression of milk during lactation