Connective Tissue Flashcards Preview

Z OLD Tissues of the Body > Connective Tissue > Flashcards

Flashcards in Connective Tissue Deck (197):
1

What does connective tissue form?

A huge continuum throughout body

2

What is the role of connective tissue?

#NAME?

3

What are the functions of blood?

#NAME?

4

What are the functions and cartilage?

Solid skeletal functions

5

Give 6 functions of connective tissues

- Provide substance and form to body and organs
- Provide medium for diffusion or nutrients and wastes 
- Attach muscle to bone, and bone to bone
- Provide cushion between tissues and organs 
- Defend against infection 
- Injury repair

6

What happens to the immune cells produced in bone marrow?

#NAME?

7

What part of connective tissue is particularly important in injury repair?

Fibroblasts

8

What do fibroblasts do?

Lay down new cellular matrix

9

What are the two main cellular tissue components?

- Cells 
- Extracellular matrix

10

Is extracellular matrix present in all connective tissues?

Many, but not all

11

What makes extracellular matrix?

Cells

12

What does extracellular matrix consist of?

- Ground substance 
- Fibres

13

What makes up ground substance?

Hyalurone proteoglycan aggregates

14

What fibres are found in the extra cellular matrix?

- Collagen 
- Reticular 
- Elastic

15

What do connective tissues differ in terms of?

- Types of cell they contain 
- Abundance / destiny of their cells 
- Constitution of the extra cellular matrix

16

What does the constitution of the extra cellular matrix differ in terms of?

- Ground substance composition 
- Fibre type, abundance and arrangement

17

What are the 3 classifications of connective tissue?

#NAME?

18

What are the embryonic connective tissues?

- Mesenchyme 
- Mucous connective tissue

19

What are the regular connective tissues?

- Loose connective tissue 
- Dense connective tissue

20

What are the types of dense connective tissue?

- Regular 
- Irregular

21

What are the specialised connective tissues?

- Adipose
- Blood
- Cartilage
- Bone 
- Lymphatic 
- Haemopoietic

22

What forms mesenchyme in the early embryo?

Mesodermal cells from the embryonic germ layer and few ectodermal cells migrate and proliferate to form mesenchyme

23

What does mesenchyme consist of?

Multipotent progenitor cells

24

What does mesenchyme give rise to?

#NAME?

25

How does mesenchyme give rise to it’s tissues?

Maturation and proliferation

26

What appearance do mesenchymal tissues from the developing foetus have?

Tapering

27

Why do mesenchymal tissues have a tapering appearance?

Because of cytoplasmic processes

28

What do mesenchymal tissues have?

An abundance of viscous ground substance in the extra cellular matrix

29

Are mesenchymal tissues morphologically similar, or do they differ?

Similar

30

What will mesenchymal cells give rise to?

Cells that differentiate into a variety of different cell types

31

Do mesenchymal tissues persist into adulthood?

Yes

32

What do mesenchymal tissues do in adulthood?

Give rise to new connective tissue cells when healing required

33

What does mucous connective tissue have?

#NAME?

34

What does the ground substance in mucous connective tissue occupy?

Large intercellular spaces

35

What is found in cartilage ground substance?

Proteoglycan

36

What does the proteoglycan monomer consist of?

Core protein

37

What is joined to the proteoglycan core protein?

~100 glycosaminoglycan (GAG) units

38

What are proteoglycan monomers attached to?

Hyaluronic acid molecules

39

What do hyaluronic acid molecules form?

Linear aggregates

40

How are proteoglycan monomers attached to hyaluronic acid molecules?

Link proteins

41

What happens to the linear aggregates of hyaluronic acid molecules?

They are interwoven with a network of collagen fibrils

42

What do GAGs attract?

Water

43

Why do GAGs attract water?

Because of the high density of negative charges on the GAGs

44

What does the attraction of water to GAGs form?

A hydrated gel

45

What forms a hyaluronate proteoglycan aggregate?

Hyaluric acid + attached proteoglycan monomers

46

What is the main constituent of ground substance?

Hyaluronate proteoglycan aggregates

47

What lie within the ground substance consisting of hyaluronate proteoglycan aggregates?

- Cells of immune system
- Fat cells 
- Fibres
- Blood vessels

48

What is the most common protein in the body?

Collagen

49

How many types of collagen have been identified?

At least 28

50

What is the most widely distributed collagen type?

I

51

Describe the structure of type I collagen

Fibrils aggregate into fibres, and fibre bundles

52

Give 3 places type I collagen is found

#NAME?

53

How does type II collagen differ from type I?

Fibrils do not form fibres

54

Give 2 places type II collagen is found?

- Hyaline cartilage 
- Elastic cartilage

55

What is type III collagen also known as?

Reticulin

56

What does reticulin do?

Forms fibres around muscle and nerve cells, and with lymphatic tissues and organs

57

What is type IV collagen?

A unique form present in the basal lamina of the basement membrane

58

What pattern does a type I collagen fibril have?

Periodic banding pattern that repeats every 68nm

59

What is each type I collagen fibril composed of?

Staggered collagen molecules

60

How big is each type 1 collagen fibril?

300nm long, 1.5nm

61

What is a type 1 collagen fibril composed of?

A triple helix of α-chains

62

What is every 3rd amino acid in a type 1 collagen fibril?

Glycine

63

What is the result of every third amino acid of type 1 collagen molecules being glycine?

It makes it a very tough, flexible molecule

64

Are are fibroblasts intimately associated with?

Collagen fibrils

65

What do collagen fibrils assemble from?

Procollagen

66

What secrete procollagen?

Fibroblasts

67

What do fibroblasts have lots of?

RER

68

What happens to collagen fibres in dense irregular connective tissues?

Thin collagen fibres aggregate in some areas to form collagen bundles

69

What does the lymph nodes capsule contain?

Collagen bundles

70

What extends form the lymph node capsule into the node?

A trabecula

71

What is the purpose of the trabecular that extends from the lymph capsule to the node?

Strength

72

What kind of collagen is important in the lymph node?

Reticular

73

What do the reticular fibres do in the lymph node?

Form an irregular anastomosing network throughout the node

74

What to the reticular fibres in the lymph nodes provide?

Something for the immune cells to bind to

75

What is densely packed in spaces between fibres in the lymph nodes?

Lymphocytes

76

What is elastin a primary component of?

Elastic fibres

77

What is elastin surrounded by?

Microfibrils called fibrillin

78

What is an elastic fibre composed of?

Elastin + fibrillin

79

Where do elastic fibres occur?

In connective tissues, to widely varying degrees

80

Where do elastic fibres have an important role?

- Dermis 
- Artery walls 
- Those sites bearing elastic cartilage

81

What is the purpose of elastic fibres in the artery walls?

It helps with blood circulation

82

How do elastic fibres appear an TEM’s?

- May have amorphous appearance and low electron density 
- May have darkly staining fibrillin around it

83

Where do fibrillin lay in relation to elastic fibres?

At periphery and within elastic fibre

84

What is the inheritance pattern of Marfan’s disorder?

Autosomal dominant

85

What happens in Marfan’s disorder?

Expression of fibrillin gene is abnormal, such that elastic tissue is abnormal

86

What is the presentation of Marfan’s disorder?

- Abnormally tall
- Exhibit arachnodactyly 
- Frequent joint dislocation 
- Can be at risk of aortic rupture

87

What are the 3 main parts of a small elastic artery?

- Tunica intima 
- Tunica media 
- Tunica adventita

88

What is present in the tunica intima?

Indistinct endothelial cells

89

What is in the tunica media?

Elastin lamallae

90

What is in the tunica adventita?

Collagen

91

What happens if the elastic fibres are compromised?

The arteries are compromised

92

How could the tunica media be described in the aorta wall?

Very thick

93

What is the aortal tunica media mainly made up of?

Elastic lamallae

94

What are aortal elastic lamallae?

Fenestrated sheets of elastic stretching around the aorta

95

Other than elastic lamellae, what else does the aortal tunica media contain?

- Collagen 
- Extracellular matrix
- Smooth muscle

96

What is the significance of the smooth muscle in the tunica media?

They produce the elastin, collagen and matrix

97

What does the mammary gland consist of?

- Glandular epithelium 
- Loose irregular connective tissue 
- Dense irregular connective tissue

98

What does the loose irregular connective tissue of the mammary gland consist of?

Wispy collagen and many fibroblasts

99

What does the dense irregular connective tissue of the mammary gland consist of?

Thicker and more abundant collagen fibres, fewer fibroblasts

100

Where is loose connective tissue found in the gut?

The lamina propria between the crypts of Lieberkühn and the submucosa of the colon

101

What does loose connective tissue consist of?

- Lots of ground substance 
- Branching elastic fibres
- Unbranching collagen fibres
- Blood vessels 
- Mast cells

102

What do the nuclei visible in micrographs of loose connective tissues mainly belong to?

Mainly fibroblasts

103

What kind of tissue is the dermis?

Loose, irregular connective tissue

104

How is collagen arranged in the dermis?

Bundles are collagen are densely packed but irregularly arranged. They are orientated in various directions

105

What is the result of the dermis having collagen having collagen fibres orientated in various directions?

The skin can resist forces in multiple directions, prevent tearing

106

What happens to skin after it’s been folded?

Elastic fibres show a degree of stretch and restoration to original shape

107

What surrounds glands?

A capsule of connective tissue

108

What kind of connective tissue is in the capsule surrounding glands?

Can vary from loose to dense

109

What does the type of connective tissue in the capsule depend on?

Location

110

What feature of the capsule differs from gland to gland?

Toughness

111

What is the purpose of the capsule?

Protects from injury and gives strength

112

Where is the capsule found?

- Adrenal gland
- Thymus gland
- Spleen
- Ovary
- Testis 
- Prostate
- Joints

Virtually every gland

113

What do tendons do?

Connect muscles to bones

114

How do the collagen bundles lie in tendons?

In parallel

115

In what direction is the densely packed formation of collagen bundles in tendons?

In line with the tensile force exerted by the muscle

116

What are tendons adapted to do?

Take pull in one direction, therefore produce tissue that can take high tensile force

117

What lies between collagen bundles in tendons?

Rows of elongated flattened fibroblasts

118

What happens between skeletal muscle and tendon collagen bundles?

They interdigitate at myotendinous junctions

119

What always lies between the collagen bundles and muscle fibres myofilaments?

The sarcolemma

120

What must be between the tendon and muscle fibre?

Very tight junctions

121

What do short ligaments do?

Connect bone to bone

122

How is collagen arranged in ligaments?

Collagen bundles densely packed in parallel arrangement, but undulate and are arranged in fascicles

123

What separates collagen bundles in ligaments?

Loose connective tissue

124

What are 6-pack muscles called?

Rectus abdominus

125

What do rectus abdominus have?

Aponeuroses

126

What are aponeuroses?

Flat tendons that are like sheets

127

What aponeuroses are present in the rectus abdominus?

#NAME?

128

What are the muscles in the sides and hips called?

External oblique muscle

129

Do the external oblique muscles have aponeuroses?

Yes

130

What does the inguinal ligament connect?

The hip bone to the pubic bone

131

What can you see of fibroblasts in micrographs?

Nuclei and cytoplasm

132

How do fibroblasts produce collagen?

They secrete procollagen in secretory vesicles, which then self assemble into collagen fibrils

133

What do fibroblasts synthesis and secrete?

Ground substance, and the fibres that are within ground substance

134

Where are fibroblasts very important?

In wound healing

135

What are fibroblast cells primarily responsible for?

Formation of scar tissue

136

What are macrophages derived from?

Blood monocytes

137

Where are blood monocytes found?

Moving around in connective tissue

138

When are blood monocytes particularly present?

If local inflammation, especially if chronic

139

What kind of role to macrophages have?

Phagocytic

140

What are macrophages able to do?

Degrade foreign organisms and cell debris

141

What are macrophages said to be professionals in?

Antigen presenting

142

What is meant by macrophages being professional antigen presenting cells?

They are able to present foreign material to T lymphocytes of the immune system

143

What do macrophages contain?

#NAME?

144

What are pinocytic vesicles important for?

Uptake

145

What do mast cells look like?

Blood basophils

146

Are mast cells derived from basophils?

No

147

What does the mast cell cytoplasm contain lots of?

Granules

148

What do mast cell granules contain?

- Heparin 
- Histamine 
- Substances that attract eosinophils and neutrophils

149

What is heparin?

An anticoagulant

150

What does histamine do?

Increase blood vessel wall permeability

151

What do mast cells do when there is a threat/trauma?

Release their granule contents very quickly

152

Where are mast cells found?

In connective tissues near blood vessels

153

Where are mast cells absent from?

CNS

154

Why are mast cells absent from the CNS?

To avoid the damaging effect of oedema there §

155

What do mast cells become coated with?

Immunoglobulin E (IgE)

156

What is IgE?

Molecules which specifically bind allergens

157

What happens when an allergen cross-links with the surface bound IgE molecules?

Contents of granules is rapidly released from mast cells

158

What can secretions of mast cell granules result in?

Immediate hypersensitivity reactions, allergy and anaphylaxis

159

What do some mesenchymal cells develop into that will eventually lead to the development of adipose tissue?

#NAME?

160

What are preadipocytes?

Fibroblast like cells which are committed to become lipoblasts

161

How does a preadipocyte become a white adipocyte?

Preadipocyte →  midstage lipoblast ↔ late lipoblast ↔ mature lipoblast (white adipocyte)

162

What do midstage lipoblasts develop?

Numerous droplets in their cytoplasm

163

What has happened in white adipose tissue?

The multiple lipid droplets fuse to form a single large droplet

164

What does the large lipid droplet in white adipocytes do?

Displaces all other cell contents to the cell periphery

165

What happens in brown adipose tissue?

The multiple lipid droplets remain separate

166

What has happened to unilocular adipose cells (fat cells)?

They have been almost completely filled by a single fat droplet, so the cytoplasm has been displaced to the rim and the nucleus is to one side

167

Of what kind is most of the adipose tissue in the body?

White

168

Why do adipose tissues appear empty in typical H&E, wax embedded preparations?

Because the toluene and xylene used in tissue preparation has dissolved alway the lipid

169

What is the role of adipose tissue?

#NAME?

170

Where is adipose tissue found in abundance?

Around joints

171

Does white adipose tissue have a lot of cellular matrix?

No

172

What do brown fat cells contain?

Many lipid droplets and a central nucleus

173

What is brown adipose tissue also known as?

Multilocular adipose cells

174

Where are brown adipose tissues found?

Close to scapula, sternum and axillae, especially in the newborn
Appear to be present in upper chest and neck of adults

175

What is the purpose of brown adipose tissue?

Thermogenesis

176

Why is brown adipose tissue brown?

Due to the rich vascular supply and abundant mitochondria

177

Why does brown adipose tissue have a rich vascular supply and abundant mitochondria?

Because it has a high respiratory capacity for generation of heat

178

How is the heat production of brown adipose tissue further promoted?

Uncoupling of oxidative phosphorylation

179

Who is non-shivering thermogenesis important in?

#NAME?

180

Where do cells of myeloid and lymphoid blood cell linages come from?

Pluripotent haemopoietic stem cell, HSC

181

What happens to HSC in development?

#NAME?

182

Why is blood a special form of connective tissue?

Because the extracellular matrix is a liquid

183

What are the different type of blood cells?

- Erythrocytes
- Neutrophils 
- Small resting lymphocytes

184

How many lobes are there in an neutrophil nucleus?

5

185

What does a stick between connecting lobes of erythrocytes indicate?

A female

186

What is true of a small resting lymphocyte until it’s activated?

It’s cytoplasm is filled by nucleus

187

Describe the matrix of cartilage

Amorphous but firm

188

What do collagen fibres form in cartilage?

An imperceptible networ

189

What produce the cartilage matrix?

Chondroblasts

190

When happens when chondroblasts mature?

They turn into chondrocytes, and lie in the lacunae

191

What are the functions of cartilage?

- Supports and reinforces
- Resilient cushioning properties 
- Resists compressive stress

192

Where is cartilage found?

- Forms most of embryonic skeleton 
- Covers end of long bonds in joint cavities 
- Forms costal cartilages of the ribs 
- Cartilages of nose, trachea and larynx

193

Describe the matrix of bone

Hard, calcified matrix containing many collagen fibres

194

Where do osteocytes lie?

In lacunae

195

Is bone well vascularised or not?

Yes, very well

196

What is the function of bone?

- Supports and protects
- Provides levers for muscles to act on 
- Stores calcium and other minerals and fats 
- Marrow inside bones is site for blood cell formation

197

What is the name for blood cell formation?

Hematopoiesis