Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Histology > Support cells and the extracellular matrix > Flashcards

Support cells and the extracellular matrix Flashcards

1
Q

2 types of cells forming tissues

A

parenchymal cells

support cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

parenchymal cells

A

subserve main function of a tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

support cells

A

provide structural scaffolding of a tissue
highly developed
complex metabolic functions
produce an extracellular matrix which defines physical characteristics of a tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

connective tissue

A

support cells and their extracellular matrix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

characteristics of support cells

A

embryological derivation from mesenchyme
production of various extracellular matrix materials
formation of sparsely cellular tissues when mature
cell adhesion mechanisms interacting with extracellular matrix materials

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

mesenchyme

A

embryonic tissue
develops from any of 3 germ layers
spindle shaped cells with large nuclei
develop into family of support cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

5 classes of support cells

A 
fibroblasts
chondrocytes
osteoblasts 
myofibroblasts
adipocytes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

fibroblasts

A

secrete extracellular matrix components in most tissues, usually collagen and elastin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

chondrocytes

A

secrete extracellular matrix components of cartilage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

osteoblasts

A

secrete extracellular matrix components of bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

myofibroblasts

A

secrete extracellular matrix components and have a contractile function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

adipocytes

A

specially adapted lipid-storing support cells
act as energy store
cushioning and padding function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

extracellular matrix composition

A

glycosaminoglycans (GAG)
fibrillar proteins
small amounts of structural glycoprotein for cell adhesion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

structure of support tissue

A

scattered network of support cells

organised, abundant extracellular network of fibrillar proteins arranged in a hydrated gel of GAG

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

glycosaminoglycans

A

large polysaccharides
give turgor
determine diffusion of substances
polysaccharides link to backbone proteins to form proteoglycans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

proteoglycans

A

polysaccharides linked to backbone proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

4 groups of GAG

A

hyaluronic acid
chondroitin sulfate and dermatan sulfate
heparin sulfate and heparin
keratan sulfate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

hydrated gel matrix

A

formed by 4 groups of GAG

properties determined by charge and spatial arrangement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

properties of GAG

A

high negative charge
strong hydrophilic behaviour
retention of positive ions and water
covalent attachment to proteins to form proteoglycans (except hyaluronic acid)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

high negative charge

A

one of the repeating units in GAG is an amino sugar (N-acetylglucosamine or N-acetylgalactosamine), commonly sulfated (SO3-) and commonly the second sugar is uronic acid with a carboxyl group (COO-)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

strongly hydrophilic behaviour

A

cannot fold into compact structures

large, permanently open coil conformation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

retention of positive ions and water

A

maintaining tissue architecture due to inherent turgor, preventing deformation by compressive forces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

covalent attachment to proteins to form proteoglycans

A

except hyaluronic acid
maintain large hydration space
allow variation in pore size of gel

basement membranes of kidney glomerulus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

hyaluronic acid properties

A

not sulfated or protein linked

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

other GAG properties

A

sulfated and protein linked

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

4 proteins forming fibrils in extracellular matrix

A

collagen
fibrillin
elastin
fibronectin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

role of fibrillar proteins

A

provide different tensile properties to support tissues

anchorage for other cellular elements in tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

collagens

A

family of closely related proteins

aggregate to produce filaments, fibrils or mesh works- interact with other proteins to provide support

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

types of collagen chains

A

20 types of collagen polypeptide chains (alpha chains) produced from different genes
combine to form different morphologic forms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

collagen families

A 
fibrillar collagens
facit collagens
short-chain collagens
basement membrane collagens 
other collagens
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

fibrillar collagens

A

types I, II, III, V, XI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

facit collagens

A

fibril associated collagen with interrupted triple helix

types IX, XII, XIV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

short chain collagens

A

types VIII, X

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

basement membrane collagens

A

type IV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

other collagens

A

VI, VII, XIII

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

collagen types I, II, III

A

arranged as rope-like fibrils - main forms of fibrillar collagen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

type I

A

large banded collagen fiber
resist tensile stresses
pink staining materials
skin dermis, tendon, bone, ligaments, fascia, fibrous cartilage, cornea, loose fibrous tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

type II

A

small banded collagen fibre

hyaline and elastic cartilage, vertebral disks, vitreous of eye

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

type III

A

small banded collagen fibre

blood vessels, parenchymal organs, bone marrow, lymphoid tissue, smooth muscle, nerves, lung, fetal skin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

reticular fibres

A

thin fibrils of type III collagen
20nm diameter
loose mesh in support tissues
zone beneath basement membranes - fibroreticular lamina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

reticular fibres in lymph nodes, spleen and bone marrow

A

form main extracellular matrix fibres supporting hemopoietic and lymphoid tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

reticular fibres in parenchymal organs

A

liver and kidney

network supporting specialised epithelial cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

type IV

A

sheet-like layers
meshwork
basement membrane, external laminae, lens capsule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

type V

A

thin fibrils

basement membrane of placenta, smooth and skeletal muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

type VI

A

thin fibrils

ubiquitous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

type VII

A

short striated fibrils

anchoring fibrils in basement membrane of skin and amnion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

type VIII

A

chains and lattices

hexagonal lattice in Descemet’s membrane in eye cornea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

type IX

A

fibril

cartilage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

type X

A

short chain

mineralising cartilage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

type XI

A

fibril

cartilage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

collagen structure

A 
precursor proteins (alpha chains) wound together to form rigid linear triple helix structures, secreted by fibroblasts
after proteolytic cleavage, triple helical portions are assembled into long filaments and incorporated into cross-linked fibres and bundles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

fibrillar collagen

A

formed from 3 polypeptide (a) chains secreted with amino and carboxyl terminal extensions to prevent collagen forming inside cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

procollagen

A

triple helix of three polypeptide (a) chains

54
Q

how do cells prevent collagen from forming inside them

A

secrete polypeptide (a) chains with amino and carboxyl terminal extensions

55
Q

tropocollagen

A

formed from cleavage of terminal extensions to leave functional mid-domains

56
Q

alignment of molecules

A

linear arrays to form long filaments
300nm long
67nm overlap/periodicity

57
Q

collagen structures

A

collagen bundle
collagen fibre
microfibrils

via lysine residues

58
Q

elastin

A

hydrophobic protein which assembles into filaments and sheets by cross linking
produced by fibroblasts

59
Q

formation of elastic fibre

A

interaction of elastin and fibrillin

fibrillin organises secreted elastin to deposit it between the microfibrils to form elastic fibres

60
Q

microfibrils

A

fibrillin is a fibril-forming glycoprotein and main component of extracellular microfibrils
constituent of elastic fibres
found in extracellular matrix of renal glomeruli (mesangium) and suspensory fibres of the lens
prominent in elastic containing matrixes
mediate adhesion between components

61
Q

fibronectin

A

multifunctional glycoprotein

3 main forms

62
Q

3 main forms of fibronectin

A

circulating plasma proteins
protein transiently attaching to surface of cells
insoluble fibrils forming part of matrix - dimers cross link via disulfide bonds

63
Q

functional importance of fibronectin

A

adheres to several different tissue components

sites bind collagen and heparin, and cell adhesion molecules

64
Q

extracellular structural glycoproteins

A

link cells to extracellular matrix via receptors

65
Q

examples of extracellular structural glycoproteins

A

laminin, tenascin, entactin

66
Q

laminin

A

sulfated glycoprotein
component of basement membranes
produced by most epithelial and endothelial cells
cross shaped molecule
binding sites for specific cell receptors, heparan sulfate, type IV collagen, entactin

67
Q

entactin

A

sulfated glycoprotein
component of basement membranes
binds with laminin
link protein, binding laminin to type IV collagen

68
Q

tenascin

A

extracellular glycoprotein
cell adhesion
embryonic tissue
cell migration in developing nervous system

69
Q

integrins

A

class of cell adhesion molecule composed of 2 protein subunits
subunit composed of 2 protein chains with a globular head
b subunit extends through membrane and binds to actin cytoskeleton

70
Q

basement membrane and external lamina

A

specialised sheet-like arrangements of extracellular matrix proteins and GAG - interface between parenchymal cells and support cells

71
Q

what are basement membranes and external lamina associated with?

A

epithelial cells, muscle cells, Schwann cells

form limiting membrane around CNS

72
Q

5 components of basement membrane

A 
type IV collagen 
laminin 
heparan sulfate
entactin
fibronextin 
minor and poorly characterised protein and GAG components
73
Q

what are the components of basement membrane synthesised by?

A

parenchymal cells - except fibronectin

74
Q

3 main functions of basement membrane

A

adhesion interface between parenchymal cells and underlying extracellular matrix

molecular sieve

controls cell organisation and differentiation

75
Q

adhesion interface between parenchymal cells and underlying extracellular matrix

A

cells have adhesion mechanisms to anchor them to BM

BM anchored to extracellular matrix of support tissues

76
Q

adhesion interface in non-epithelial tissues

A

external lamina

77
Q

molecular sieve

A

pore size depends on charge and spatial arrangement of GAG

prevents proteins leaking into tissues, protein loss from filtered blood and gaseous diffusion

78
Q

cell organisation and differentiation

A

mutual interaction of cell surface receptors and molecules in the extracellular matrix

79
Q

staining of BM

A

0.5mm thick and stains poorly - no H&E

faint magenta stained line with PAS due to glycoprotein

80
Q

laminae of BM

A

lamina lucida - 60nm wide, between cell and lamina densa. lucent zone

lamina densa - dark-staining band 30-100nm thick

fibroreticular lamina - below lamina densa, merges with fibrous proteins of extracellular matrix.

81
Q

3 main mechanisms by which fibroreticular lamina anchors BM to extracellular matrix

A

extension of lamina densa into fibroreticular lamina interacts with collagen (esp. type III)

fibrillin microfilaments link to BM and to elastic tissue in extracellular matrix

anchoring fibrils of type VII collagen link BM to matrix in skin and amnion via hemidesmosomes

82
Q

types of junctions between cells and extracellular matrix

A

hemidesmosomes
focal contacts
laminin receptors
non-integrin glycoproteins

83
Q

hemidesmosomes

A

anchor intermediate filament cytoskeleton to BM

84
Q

focal contacts

A

anchor actin cytoskeleton to BM

mediated through fibronectin receptor

85
Q

laminin receptors

A

anchor cells to BM where laminin is major component

86
Q

non-integrin glycoproteins

A

bind to collagen and other cell matrix components

87
Q

blast vs cyte

A

blast - cell is actively growing or secreting extracellular matrix material
cyte - quiescent phase

88
Q

fibroblasts

A

produce fibrocollagenous tissue composed of collagen fibres associated with GAG, elastic fibres and reticular fibres

89
Q

what is fibrocollagenous tissue composed of?

A

collagen fibres associated with GAG, elastic fibres and reticular fibres

90
Q

loose fibrocollagenous tissue

A

collagen fibres are thin, haphazardly arranged and widely spaced

91
Q

dense fibrocollagenous tissue

A

collagen fibres are broad and virtually confluent

92
Q

what does organisation and collagen orientation depend on?

A

varies between sites depending on local tissue stresses

93
Q

highly organised dense fibrocollagenous tissue

A

forms tendons and ligaments

94
Q

functions of fibrocollagenous tissue

A

support of nerves, blood vessels and lymphatics

separation of functional layers in organs and tissues - loose, mobility and stretching

support for transient and resident immune cell populations

formation of fibrous capsule surrounding most parenchymal organs

tissue repair (fibroblasts)

95
Q

myofibroblasts

A

aggregates of actin fibres associated with myosin - contractility

small amounts in support tissue

immunohistochemistry or ultrastructural methods

develop during repair after tissue damage

96
Q

myofibroblasts in repair after tissue damage

A

proliferation of normally inconspicuous tissue myofibroblasts
differentiation of fibrocytes

produce collagen

retraction and shrinkage of early fibrocollagenous scar tissue

97
Q

benign and malignant tumors arising from fibroblasts

A

fibroma

fibrosarcoma

98
Q

benign and malignant tumors arising from chondrocytes

A

chondroma

chondrosarcoma

99
Q

benign and malignant tumors arising from adipocytes

A

lipoma

liposarcoma

100
Q

chondroblasts

A

produce cartilage

101
Q

cartilage components

A 
fibrous proteins (predom. type II) - mechanical stability
abundant GAG - resist deformation by compressive forces

collagen fibres thin and in interwoven lattice, merges into extracellular matrix of adjacent support tissues
GAG (hyaluronic acid, chondroitin sulfate and keratan sulfate) bound to core protein aggrecan to form proteoglycan - linked to collagen lattice by link protein

102
Q

staining of cartilage

A

H&E - blue

due to sulfated GAG

103
Q

properties of cartilage

A

inherent turgor resisting deformation by tightly bound proteoglycans forming a hydrated matrix

small molecules diffuse freely through extracellular matrix

104
Q

development of chondroblasts

A

from embryonic mesenchyme
appear as clusters of vacuolated rounded cells
spindle shaped cells of surrounding undifferentiated mesenchyme develops into fibroblasts

105
Q

perichondrium

A

confining sheet of cells

106
Q

structure of chondroblasts

A

abundant glycogen and lipid
basophilic cytoplasm - active synthesis of matrix
RER

107
Q

interstital growth

A

proliferation of chondroblasts within established matrix

108
Q

appositional growth

A

development of new chondroblasts from perichondrium

109
Q

chondrocytes

A

become less metabolically active with small nuclei and pale, indistinct cytoplasm after depositing cartilage

110
Q

3 types of cartilage

A

hyaline
fibrocartilage
elastic

111
Q

hyaline cartilage

A

type II collagen only
forms temporary skeleton until bone in fetal development
growing point in long bones in childhood, articular surface in joints and support tissue in respiratory passages

112
Q

fibrocartilage

A

type II and type I collagen

intervertebral disks, tendon attachments to bones and junctions between flat bones of pelvis

113
Q

elastic cartilage

A

elastic fibres and type II collagen

auricle of ear, walls of external auditory canal and eustachian tubes, epiglottis of larynx

114
Q

osteoblasts

A

elaborate support matrix of bone - osteoid - calcifies to form bone

115
Q

osteoid

A

type I collagen
extracellular GAG chondroitin sulfate and keratan sulfate
sialoprotein and osteocalcin found in bone matrix and bind calcium

116
Q

glycoproteins found in osteoid

A

sialoprotein and osteocalcin

117
Q

adipocytes

A

intracellular storage of fat

118
Q

2 types of fat storing tissue

A

unilocular

multilocular

119
Q

uniloclar adipose tissue

A

white fat

develops from embryonic mesenchyme with formation of lipoblasts (spindle shaped cells) containing small fat vacuoles

120
Q

lipoblasts

A

spindle shaped cell
spindle shaped mesenchymal cells accumulate fat in cytoplasm in multiple small vacuoles
vacuoles form larger perinuclear vacuole
maturing lipoblasts lose spindle shape
cytoplasm becomes attenuated around single lipid vacuole, nucleus displaced to one side
produces extracellular matrix material and BM forms around cell

121
Q

adipocytes structure

A 
prominent SER
pinocytotic vesicles
lipid biosynthesis and transport
surrounded by external lamina
extracellular matrix composed of reticular fibres
122
Q

multilocular tissue

A 
brown fat 
newborns
development separate from uniloular tissue
metabolises fat to produce heat
lost in childhood
123
Q

ultrastructure of multilocular tissue

A

mitochondria

lipid vacuoles

124
Q

staining of multilocular tissue

A

eosinophilia seen histologically

brown colour seen macroscopically

125
Q

why does multilocular tissue have its name?

A

cells contain multiple small lipid droplets

126
Q

where is multilocular tissue concentrated?

A

support tissues in neck, shoulders, back, perirenal and para-aortic regions

127
Q

2 populations of cell in multilocular tissue

A

lipid-rich cells with central nucleus and multiple small unstained vacuoles
polyhedral shaped cells with granular, pink stained cytoplasm, central nucleus and occasional lipid vacuoles

128
Q

secretory role of adipocytes

A

modulate energy metabolism
influence general metabolism in coordination with hormones
secretion of proteins into blood (adipocytokines)

129
Q

adipocytes function and types

A

secretion of proteins into blood

leptin, adipsin, resistin, adiponectin, tumor necrosis factor alpha (TNF)-alpha, plasminogen-activator inhibitor type 1

130
Q

how is unilocular tissue as a support tissue and energy store?

A

receptors for growth hormone, insulin, glucocorticoids, thyroid hormones, norepinephrine

rich capillary blood supply and innervation by ANS
release of noradrenaline stmulates release of stored fat into blood

organisation into pads by sheets of fibrocollagenous tissue as deformable shock absorbing tissues

131
Q

multilocular lobules

A

capillary vascular supply and thin fibrocollagenous septa divides tissue into small lobules

Histology (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions