Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

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
other GAG properties
sulfated and protein linked
26
4 proteins forming fibrils in extracellular matrix
collagen fibrillin elastin fibronectin
27
role of fibrillar proteins
provide different tensile properties to support tissues | anchorage for other cellular elements in tissues
28
collagens
family of closely related proteins | aggregate to produce filaments, fibrils or mesh works- interact with other proteins to provide support
29
types of collagen chains
20 types of collagen polypeptide chains (alpha chains) produced from different genes combine to form different morphologic forms
30
collagen families
``` fibrillar collagens facit collagens short-chain collagens basement membrane collagens other collagens ```
31
fibrillar collagens
types I, II, III, V, XI
32
facit collagens
fibril associated collagen with interrupted triple helix | types IX, XII, XIV
33
short chain collagens
types VIII, X
34
basement membrane collagens
type IV
35
other collagens
VI, VII, XIII
36
collagen types I, II, III
arranged as rope-like fibrils - main forms of fibrillar collagen
37
type I
large banded collagen fiber resist tensile stresses pink staining materials skin dermis, tendon, bone, ligaments, fascia, fibrous cartilage, cornea, loose fibrous tissue
38
type II
small banded collagen fibre | hyaline and elastic cartilage, vertebral disks, vitreous of eye
39
type III
small banded collagen fibre | blood vessels, parenchymal organs, bone marrow, lymphoid tissue, smooth muscle, nerves, lung, fetal skin
40
reticular fibres
thin fibrils of type III collagen 20nm diameter loose mesh in support tissues zone beneath basement membranes - fibroreticular lamina
41
reticular fibres in lymph nodes, spleen and bone marrow
form main extracellular matrix fibres supporting hemopoietic and lymphoid tissues
42
reticular fibres in parenchymal organs
liver and kidney | network supporting specialised epithelial cells
43
type IV
sheet-like layers meshwork basement membrane, external laminae, lens capsule
44
type V
thin fibrils | basement membrane of placenta, smooth and skeletal muscle
45
type VI
thin fibrils | ubiquitous
46
type VII
short striated fibrils | anchoring fibrils in basement membrane of skin and amnion
47
type VIII
chains and lattices | hexagonal lattice in Descemet's membrane in eye cornea
48
type IX
fibril | cartilage
49
type X
short chain | mineralising cartilage
50
type XI
fibril | cartilage
51
collagen structure
``` 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 ```
52
fibrillar collagen
formed from 3 polypeptide (a) chains secreted with amino and carboxyl terminal extensions to prevent collagen forming inside cells
53
procollagen
triple helix of three polypeptide (a) chains
54
how do cells prevent collagen from forming inside them
secrete polypeptide (a) chains with amino and carboxyl terminal extensions
55
tropocollagen
formed from cleavage of terminal extensions to leave functional mid-domains
56
alignment of molecules
linear arrays to form long filaments 300nm long 67nm overlap/periodicity
57
collagen structures
collagen bundle collagen fibre microfibrils via lysine residues
58
elastin
hydrophobic protein which assembles into filaments and sheets by cross linking produced by fibroblasts
59
formation of elastic fibre
interaction of elastin and fibrillin | fibrillin organises secreted elastin to deposit it between the microfibrils to form elastic fibres
60
microfibrils
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
fibronectin
multifunctional glycoprotein | 3 main forms
62
3 main forms of fibronectin
circulating plasma proteins protein transiently attaching to surface of cells insoluble fibrils forming part of matrix - dimers cross link via disulfide bonds
63
functional importance of fibronectin
adheres to several different tissue components | sites bind collagen and heparin, and cell adhesion molecules
64
extracellular structural glycoproteins
link cells to extracellular matrix via receptors
65
examples of extracellular structural glycoproteins
laminin, tenascin, entactin
66
laminin
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
entactin
sulfated glycoprotein component of basement membranes binds with laminin link protein, binding laminin to type IV collagen
68
tenascin
extracellular glycoprotein cell adhesion embryonic tissue cell migration in developing nervous system
69
integrins
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
basement membrane and external lamina
specialised sheet-like arrangements of extracellular matrix proteins and GAG - interface between parenchymal cells and support cells
71
what are basement membranes and external lamina associated with?
epithelial cells, muscle cells, Schwann cells | form limiting membrane around CNS
72
5 components of basement membrane
``` type IV collagen laminin heparan sulfate entactin fibronextin minor and poorly characterised protein and GAG components ```
73
what are the components of basement membrane synthesised by?
parenchymal cells - except fibronectin
74
3 main functions of basement membrane
adhesion interface between parenchymal cells and underlying extracellular matrix molecular sieve controls cell organisation and differentiation
75
adhesion interface between parenchymal cells and underlying extracellular matrix
cells have adhesion mechanisms to anchor them to BM | BM anchored to extracellular matrix of support tissues
76
adhesion interface in non-epithelial tissues
external lamina
77
molecular sieve
pore size depends on charge and spatial arrangement of GAG | prevents proteins leaking into tissues, protein loss from filtered blood and gaseous diffusion
78
cell organisation and differentiation
mutual interaction of cell surface receptors and molecules in the extracellular matrix
79
staining of BM
0.5mm thick and stains poorly - no H&E | faint magenta stained line with PAS due to glycoprotein
80
laminae of BM
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
3 main mechanisms by which fibroreticular lamina anchors BM to extracellular matrix
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
types of junctions between cells and extracellular matrix
hemidesmosomes focal contacts laminin receptors non-integrin glycoproteins
83
hemidesmosomes
anchor intermediate filament cytoskeleton to BM
84
focal contacts
anchor actin cytoskeleton to BM | mediated through fibronectin receptor
85
laminin receptors
anchor cells to BM where laminin is major component
86
non-integrin glycoproteins
bind to collagen and other cell matrix components
87
blast vs cyte
blast - cell is actively growing or secreting extracellular matrix material cyte - quiescent phase
88
fibroblasts
produce fibrocollagenous tissue composed of collagen fibres associated with GAG, elastic fibres and reticular fibres
89
what is fibrocollagenous tissue composed of?
collagen fibres associated with GAG, elastic fibres and reticular fibres
90
loose fibrocollagenous tissue
collagen fibres are thin, haphazardly arranged and widely spaced
91
dense fibrocollagenous tissue
collagen fibres are broad and virtually confluent
92
what does organisation and collagen orientation depend on?
varies between sites depending on local tissue stresses
93
highly organised dense fibrocollagenous tissue
forms tendons and ligaments
94
functions of fibrocollagenous tissue
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
myofibroblasts
aggregates of actin fibres associated with myosin - contractility small amounts in support tissue immunohistochemistry or ultrastructural methods develop during repair after tissue damage
96
myofibroblasts in repair after tissue damage
proliferation of normally inconspicuous tissue myofibroblasts differentiation of fibrocytes produce collagen retraction and shrinkage of early fibrocollagenous scar tissue
97
benign and malignant tumors arising from fibroblasts
fibroma | fibrosarcoma
98
benign and malignant tumors arising from chondrocytes
chondroma | chondrosarcoma
99
benign and malignant tumors arising from adipocytes
lipoma | liposarcoma
100
chondroblasts
produce cartilage
101
cartilage components
``` 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
staining of cartilage
H&E - blue | due to sulfated GAG
103
properties of cartilage
inherent turgor resisting deformation by tightly bound proteoglycans forming a hydrated matrix small molecules diffuse freely through extracellular matrix
104
development of chondroblasts
from embryonic mesenchyme appear as clusters of vacuolated rounded cells spindle shaped cells of surrounding undifferentiated mesenchyme develops into fibroblasts
105
perichondrium
confining sheet of cells
106
structure of chondroblasts
abundant glycogen and lipid basophilic cytoplasm - active synthesis of matrix RER
107
interstital growth
proliferation of chondroblasts within established matrix
108
appositional growth
development of new chondroblasts from perichondrium
109
chondrocytes
become less metabolically active with small nuclei and pale, indistinct cytoplasm after depositing cartilage
110
3 types of cartilage
hyaline fibrocartilage elastic
111
hyaline cartilage
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
fibrocartilage
type II and type I collagen | intervertebral disks, tendon attachments to bones and junctions between flat bones of pelvis
113
elastic cartilage
elastic fibres and type II collagen | auricle of ear, walls of external auditory canal and eustachian tubes, epiglottis of larynx
114
osteoblasts
elaborate support matrix of bone - osteoid - calcifies to form bone
115
osteoid
type I collagen extracellular GAG chondroitin sulfate and keratan sulfate sialoprotein and osteocalcin found in bone matrix and bind calcium
116
glycoproteins found in osteoid
sialoprotein and osteocalcin
117
adipocytes
intracellular storage of fat
118
2 types of fat storing tissue
unilocular | multilocular
119
uniloclar adipose tissue
white fat | develops from embryonic mesenchyme with formation of lipoblasts (spindle shaped cells) containing small fat vacuoles
120
lipoblasts
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
adipocytes structure
``` prominent SER pinocytotic vesicles lipid biosynthesis and transport surrounded by external lamina extracellular matrix composed of reticular fibres ```
122
multilocular tissue
``` brown fat newborns development separate from uniloular tissue metabolises fat to produce heat lost in childhood ```
123
ultrastructure of multilocular tissue
mitochondria | lipid vacuoles
124
staining of multilocular tissue
eosinophilia seen histologically | brown colour seen macroscopically
125
why does multilocular tissue have its name?
cells contain multiple small lipid droplets
126
where is multilocular tissue concentrated?
support tissues in neck, shoulders, back, perirenal and para-aortic regions
127
2 populations of cell in multilocular tissue
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
secretory role of adipocytes
modulate energy metabolism influence general metabolism in coordination with hormones secretion of proteins into blood (adipocytokines)
129
adipocytes function and types
secretion of proteins into blood | leptin, adipsin, resistin, adiponectin, tumor necrosis factor alpha (TNF)-alpha, plasminogen-activator inhibitor type 1
130
how is unilocular tissue as a support tissue and energy store?
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
multilocular lobules
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.
© 2025 Bold Learning Solutions. Terms and Conditions