Connective Tissue Flashcards
1
Q
what provides the supportive and connective famework (or stroma( for all tissues of the body
A
connective tissue
2
Q
What is connective tissue formed by?
A
cells and ECM
3
Q
Is connective tissue vascular or avascular?
A
Connective tissue is directly supplied by blood and lymphatic vesselsI
4
Q
What is ECM made out of ?
A
mixture of collagens, noncollagenous glycoproteins, and proteoglycans surrounding connective tissue
5
Q
What is the role of connective tissue in the body?
A
Mechanical role: supporting and tissue repair Defensive role: inflammation (first reaction of defense) and immune responses Metaboliclly: Energy storage (adipose tissue) Template for bone formation: cartilage
6
Q
What produces CT and ECM?
A
fibroblast
7
Q
What is chondroblast?
A
a type of fibroblast that produces cartiledge
8
Q
What are the three major groups of connective Tissue?
A
Embryonic Adult Special
9
Q
Describe Embryonic CT
A
hydrophilic mainly ECM Whartons Jelly
10
Q
Describe Adult CT
A
Loose Dense (regular and irregular) *structural diversity: the proportion of cells to fibers and ECM varies from tissue to tissue) therefore LooseCT and Dense CT
11
Q
Describe Special Connective Tissue
A
Adipose Tissue Bone Tissue Cartiledge Hematopoeitic Tissue (bone marrow, reticular)
12
Q
What are the major components of CT?
A
Fibers:Collagen, Elastic, Reticular Fibers Cells: resident (fibroblast), immagrant cells ECM ground substance):collagen, non-collagenous proteins and proteoglycans(trap water)
13
Q
Fibroblast make
A
connective tissue fibers and ECM
14
Q
Reticular CT
A
provide delicate meshwork to allow passage of cells and fluid
15
Q
Elastic CT
A
provides elasticity (ligaments of vertebral column and wall of aorta)
16
Q
How is CT classified?
A
- proportion of cells, fibers, and ECM : dense or loose 2. Organization of fibers: regular or irregular
17
Q
Embryonic CT
A
loose connective tissue covered by amnion the major component is hydrophilic ECM has alot of proteoglycans
18
Q
What type of consistency does embryonic CT have?
A
jelly like…Whartons Jelly (mucoid CT)
19
Q
Where is embryonic Connective Tissue Found?
A
Umbilical Cord Pulp of developing tooth
20
Q
Loose CT
A
Has MORE CELLS than collagen fibers
21
Q
What type of cells do fibroblast have ?
A
oval nucleur shape
22
Q
Where is loose CT found?
A
mucosa and submucosa and surrounding blood vessels, nerves and muscles
23
Q
Dense connective Tissues
A
MORE COLLAGEN FIBERS than cells dense regular Ct ( tendons, ligaments, cornea) dense irregular CT( reticular fibers and elastic fibers)
24
Q
Metachromasia
A
change in color of staining shift in color of a dye from blue to purple DENSE CONNECTIVE
25
Types of Fibers and cells in Loose Connective Tissue
Fibers: abundant elastic fibers and collagen bundles embedded in ECM Cells: fibroblast-active cell (fibrocyte-not so active cell), mast cells, machrophages and blood capillaries
26
Where is Dense irregular CT found?
dermis (stratified squamous epithelium) submucosa of digestive tube more COLLAGEN FIBERS than cells
27
What are the cells present in Dense irregular CT?
Sparse fibroblast (separated by collagen bundles), mast cells, and marcphages
28
how to tell if dense irregular CT is making collagen?
if the nucleus is big cell is making collagen from the fibroblast when the nuclus is smaller then usual the cell is not making collagen (fibrocytes)
29
Describe dense regular connective tissue
regularly arranged collagen bundles compressed oval nucleus of the fibrocyte
30
What are the four major cell components of CT?
fibroblast (resident cells) macrophages mast cell plasma cell
31
What type of tissue is arygophilic
Reticular Tissue (can be identified ins torma of lymphatic nodule after being saturated with silver salts)
32
What type of tissue is RETICULAR CT?
adult dense irregular CT which reticular fibers predominate thing and branching strucutures
33
What is reticular tissue characteristic of?
lymphatic tissues
34
Reticular fibers are synthesized by?
fibroblast (reticular cells)
35
Reticular fibers form meshwork in which
lymphoid cells are embbeddded
36
Argrophilia
affinity for silver
37
Reticular tissue is what type of collagen?
type III
38
Reticular tissue is seen in....
lymphatic tissue and in bone marrow
39
Elastic Fibers are produced by
fibroblast and smooth muscle fibers
40
What type of CT is elastic?
adult dense irregular CT elastic fibers predominate and there is NO COLLAGEN!
41
Elastic tissue is characteristic of?
large blood vessels and ligaments
42
DEscribe the elastic fibers found in the wall of a blood vessel?
They are synthesized by smooth muscle cells and form discontinuous and concentric arrangements
43
What appear as wavy bands?
elastic tissue
44
Fibroblast synthesize and secrete
(ECM+COLLAGEN) BASIC SPECIFIC proteoglycans glycoproteins collagens (5 types) elastin fibronectin (glycoprotein) heparan sulfate proteoglycan
45
What do fibroblast synthesize that are part of the basement membrane?
fibronectin heparan sulfate
46
Collagen is a compondent of
collagen and the reticular fibers
47
What type of collagen is seen in the basal lamina?
type IV
48
What are the types of fibroblast?
reticular cells osteoblast (bone) chondroblast (cartilage) odontoblast (teeth)
49
Are reticular fibers PAS Positive?
reticular fibers and collagens in general are glycoproteins and therefore pas positive
50
Type I collagen
Fibrocartilage fibrillar Tendon, bone,dentin and dermis
51
Type II collagen
fibrillar ( thinner than type 1) Cartilage: hyaline and elastic
52
Type III
fibrillar lymphoid tissue Reticular collagen-\> precollagen reticular lamina wound healing (replaced by type I) argyrophillic
53
Type IV
layers basal lamina binds to laminin does not form bundles
54
Type V
fibrillar amnion and chorion (in fetus) muscle and tendon sheaths doesnt form banded fibrils
55
Name the fibrillar collagen(s)?
Types: I, II, III, V
56
Name the non-fibrillar collagen(s)?
Type IV
57
Synthesis of Collagen Steps
In the RER 1. synthesis of precollagen and procollagen (triple helical arrangement of procollagen) 2. hydroxylation of lysine and proline by lysyl hydroxylase occurs in procollagen (requires vitamin c\_scurvy) 3. glycosylation and disulfide bond formation Golgi apparatus 5packing and secretion of hydroxylated pro collagen Outside the cell 6.procollagen peptidase removes non helical end of procollagen and it becomes tropocollagen 7. Self-aggregation of tropocollagen molecule leads to formation of collagen fibrils (staggered array) 8. cross linking of collagen fibrils to form collagen fibers (FACIT COLLAGEN) 9. collagen bundle formation by proteoglycans and other glycoproteins
58
FACIT
fibril associated collagens with interrupted helices
59
lysl oxidase
cross links tropocollagen molecules stabilize staggered arangment of collagen fibrils to form fibers
60
Ethers Danlos Syndrome
hyperelasticty of skin and hypermobility of joints (dislocation) -defects in synthesis of procollagen collagen -type 1 collagen defect -mutations in procollagen peptidase or lysyl hydroxylase -cant form collagen fibers -defects in blood vessels and internal organs
61
procollagen peptidase
forms tropocollagen
62
lysyl hydroxylase
hydroxylation of lysine and proline needs vitamin c
63
Elastic Fibers is made in
RER and Golgi apparatus
64
Assembly of Elastin Fibers
RER 1. synthesis of 3 components of elastic fibers (fibulin 1, fibrillins 1 &2, tropoelastin) becomes proelastin Golgi proelastin is packaged and secreted into the extracellular space where it turns into tropoelastin ( with desmosine attached) Extracellular Space Assembly of fibulin 1, fibrillins and tropoelastin to produce elastic fibers
65
Elastic Fibers are made by
fibroblast and smooth muscle cells
66
Fibrillin 1
forcing bearing structural support
67
fibrillin 2
regulates the assembly of the elastic fiber
68
fibulin 1
required for co-assembly of fibrillins and elastin subunits
69
what type of fibroblast produce elastic fibers?
embryonic and juvenile fibroblast
70
Many tissues become \_\_\_\_elastic with age?
less elastic wrinkles
71
Marfans Syndrome
Issue with fibrillin 1 (chromosome 15) Increase in proteoglycans (they replace elastic lamallae) dilation of aorta mitral valve prolapse aortic dissection
72
Describe the periosteum in Marfans syndrome
abnormally elastic and does not provide oppositional force during development
73
Functions of Macrophage
1. turn over senescent (old) fibers and ECM material 2. present antigens to lymphocytes as part of inflammatory and immunologic responses \*\* ANTIGEN PRESENTING CELLS 3. Produces cytokines
74
where do macrophages derive from?
monocytes (cells formed in bone marrow)
75
what is a kupffer cell?
macrophage of the liver capture particles in liver blood cirulation
76
what is a osteoclast
macrophage of the bone dissolve bone during remodeling or when calcium in blood decreases
77
what is a microglial cell
macrophage of CNS removal of debris when there is destruction of cells in CNS
78
Where do monocytes ciruclate?
in the blood and migrate into the CT where they differentiate into macrophages
79
Macrophages have MHC
major histo compatibility complex 1. contain abundant lysosomes for breakdown of phagocytic materials have numerous phagocytic vesicles (phagosomes) for storage of ingest materials 3. nucleus has irregular outline
80
Macrophages as antigen presenting cells
put desktop picture on it
81
Mast Cells
source of vasoactive mediator (contained in cytoplasmic granules) metachromasia
82
What do the cytoplasmic granules of mast cells contain?
histamine heparin chemotatic mediators
83
What are vasoactive products of mast cells?
leukotrines
84
leukotrines
-are NOT present in granules -are leased from the cell membranes of mast cells -full of granules that form once the cell reaches the connective tissue
85
Name the types of Mast Cells
Mucosal MC Connective Tissue MC
86
Mucosal MC
predominantly in the intestines and lungs
87
Connective Tissue MC
granules more abundant in CT mast cells
88
what is a vasoactive mediator
mediates constriction and dilation of blood vessels
89
Origin of Mast Cells
bone marrow progenitor/precursor (lack cytoplasmic granules) when they migrate into the CT/lamina propria they proliferate and accumulate cytoplasmic granules
90
The migration of mast cells from bone marrow to tissue is regulated by
c-kit receptor (tyrosine kinase) and its ligand \*(stem cell factor)
91
Clinical Significance of Mast Cells (antigen)
1. Antigen(allergen) binds to two adjacent IgE receptors and mast cell becomes IgE-sensitized 2. IgE-sensitized mast cell releases intracellular calcium 3. contents of cytoplasmic granules is rapidly discharged by degranulation 4. the degranulation will release histamine protease, and proteoglycans 5. synthesize inflammatory mediators derived from arachidonic acid (not present in granules ): cychoxygenase pathway-prostagladin d2 lipoxygenase-leukotrine c4
92
what occurs with excessive mast cell degranulation
allergic hypersensitivity reaction leads to shock (rapid drop inb lood, asthma hay fever eczema
93
Mast cell releases
-granule mediators (histamine, heparin, tryptase, chymase) -lipid mediators ( leukotrine) -cytokines (signaling molecules produced by specific cells of immune system)
94
Explain Asthma
release of histamine causes dyspnea (difficulty breathing) do to contraction of smooth muscle surrounding bronchioles and hyper-secretion of goblet cells and mucosal glands of bronchi
95
explain hay fever
histamine increases vascular permeability leading to edema (accumulation of fluid) -leukotrines induce increased vascular permeability associated with urticaria (swelling in dermis of skin) (vascular permeability is the permeability of blood vessels)
96
Plasma cells produce
all immunoglobins (single type per each plasma cell)
97
Plasma cells
well developed RER well developed golgi apparatus (gives light staining over nucleus & packages proteins) cartwheel nucleus (because of heterochromatin)
98
What are plasma cells derived from?
B lymphocytes (B cells)
99
Is the cytoplasm of plasma cells acidophilic or basophilic?
basophillic
100
The area around the nucleus of plasma cell becomes
slightly acidophilic
101
Cartwheel nucleus
plasma cell
102
How plasma cells are created
put desktop pic #2 1. antigen is taken up by a macrophage 2. the antigetn is stored in phagocytic vesicle which then fuses with a lysosome to become a phagosome 3. the phagosome has an acidic pH therefore it breaks up the antigen into small peptides 4. the small peptides attach to the MHC which is then exposed to TCELLS 5. the TCELLS then secrete cytokines or interleukins that bind to nearby B cells which are then induced into mitosis 6. the increased number of B cells now undergo differention into Ig secreting plasma cells
103
Adipose Cells
have MORE CELLS then collagen fibers and ground substance -most significant energy storage site in the bodyq
104
Cartilage and Bone
Both are dense CT with specialized cells
105
what type of ECM does cartilage have? Calcified or non calcified?
has non calcified ECM
106
what type of ECM does bone have? Calcified or non calcified?
calcified
107
What are the types of adipose cells?
Brown White
108
Brown adipose Cells
Multiocular store MANY lipid droplets and mitocondria thermogenic -dissipates energy instead of storing energy -heat generated by uncoupling production of ATP (UCP-1) -surrounded by alot of blood vessels
109
White adipose cells
Unicocular store SINGLE lipid inclusion provides a cushion and storage of energy (major reserve of long term energy)
110
Fat cells derive from
preadipocyte cells which derive from mesenchymal cell precursor
111
What is the effect of insulin on fat
insuling binding to insulin like growth factor 1 (IGF-1) causes preadipocytes to synthesize lipoprotein lipase (blood to fat cell transfer) this leads to primary fat cell formation in fetus
112
Obesity
disorder of energy balence accumulation of fat in liver insulin resistence dyslipidemia (alterations in blood fat levels) cardiovascular disease
113
Leptin
secreted by adipocytes regulates body weight
114
what occurs if one is leptin deficient
infertile and obese
115
leptin receptors share the same sequence as
cytokines receptors therefore it influences responses to infection and inflammatory responses
116
White fat nucleus
pushed to eccentric side position
117
\_\_\_\_\_\_\_fat lipids are in direct contact with cytosol
white
118
\_\_\_\_\_\_\_\_fats do not contain a cytomembrane
white
119
Which has a more extensive blood supply? white or brown fat?
brown
120
What are the two requirements for thermogenisis?
1. mitochondrial biogenesis (production of new mitocondria) 2. uncoupling protein-1
121
Fat stains
xylene-dissolves fat/ only nucleus and plasma membrane left osimium tetroxide-stains fat brown (lipid rich myelin in nerves) SudanIII-alchoholic solution used for detection of fat in frozen sections
122
Where do chondroblast derive from?
mesenchymal cells
123
What are the three major types of cartilage?
hyaline elastic fibrocartilage
124
is cartilage vascular or avascular?
avascular nutrients are received by diffusion
125
Cartilage is made by?
chrondoblast/chrondcytes
126
Cartilage is surrounded by\_\_\_\_\_\_
Perichondrium
127
Perichondrium
layer of undifferentiated cells that differentiate into chondroblast
128
chrondrocytes rarely
divide
129
Interstitial growth versus appositional growth
Interstitial growth-chondrocytes within the cartilage appositional growth-undifferentiated cells at the surface of the cartilage or perichondrium
130
Interstitial growth
mesenchymal cells turn into chondroblast 2. which form centers of chondrogenisis ( chondroblast surrounded by ECM) 3. the chondroblast divide by mitosis produce type II collagen, hyaluronic A, GAGS and form isogenous cell groups (daughter cells aka chondrocytes remaining in the same space lacunae) 4. isogenous cell group is surrounded by territorial matrix 5. wider interterritorial matrix surrounds the territorial matrix ACTIVE DURING ENDOCHONDRIAL OSSIFICATION
131
What do chondroblast deposit during mitosis?
type II collagen fibers hyaluronic acid GAGS
132
Appositional Growth
1. outermost cells of perichondrium (transitional zone between cartilage and surrounding CT) fibrous layer 2. inner cells of perichondrium (chondrogenic layer) differentiate into chondroblast and release type II collagen 3. new layer of carilage added and increases size of intial (anlagen/outline) 4. collagen grows
133
Chondroblast are a type of
fibroblast
134
Compomelic dysplasia
-mutation of sox 9 TF -encodes expression of type II collagen and proteoglycan ggrecan -with mutation null cells remain in perichondrium do not diff into chondrocytes
135
When chondroblast are trpped within spaces in the matrix called lacunae the cells are called
chondrocytes
136
What type of collagen does hyaline have?
type II
137
what type of collagen does elastic cartilage have?
type II
138
what type of collagen does fibrocartilage have?
type I
139
What type of cartilage has type II collagen?
hyaline and elastic
140
What are the special functions of hyaline cartilage?
shock absorber lubricated surface for joints
141
What type of cartilage lacks a perichondrium?
Fibrocartilage
142
where is hyaline cartilage found?
articular cartilage (area of body not lined by epithelium) temporary skeleton of fetus HIGH WATER CONTENT
143
where is elastic cartilage found?
external ear epiglottis auditory tube EVERY FLEXIBLE ECM CONTAINS ABUNDANT ELASTIC FIBERS
144
where is fibrocartilage found?
intervertebral disk, pubic symphysis articular disk of the knee ECM HAS LOW CONCENTRATION OF PROTEOGLYCANS AND WATER
145
how to distinguish between fibrocartilage and dense connective tissue?
pictures
146
Fibrocartilage is consisdered an intermediate between
hyaline cartilage and dense regular connectivetissue
147
148
What type of adipose tissue is this?
What is the top line ?
What is the bottom line?
brown adipose tissue
blood vessels
mutliocular adipocyte
149
What type of adipocyte is this?
What is the top line
what is the bottom line
White
eccentric nucleusuniolcular adipocyte
150
What type of CT is this?
Line 1 (top)
LIne 2
embroyonic (whartons jelly)
nuclus of mesenchymal cell embedded in ECM
amnion
151
What type of CT is this?
Line 1
Line 2
Line 3
adult connective
Loose (areolar)
Line 1-oval nuclus of fibroblast
elastic fibers (thin straight and branching
collagen bundles (thick and wavy)
152
What type of CT is this?
Line 1
LIne 2
LIne 3
adult CT
dense irregular
oval nuclus of fibroblast
collagen bundles (thick wavy and irregularly arranged)
153
What type of CT is this?
Line 1
LIne 2
LIne 3
Adult CT
dense regular
1-skeletal muscle
2. regulary arranged collaen bundles
oval nucleus of birobcyte compressed by the regulary aligned collagen bundles
154
What type of CT is this?
Reticular tissue
155
what type of Ct is this?
line 1
bottom line
elastic tissue
elastic fibers
smoth muscle cells
156
What are these special types of CT?
adipose
cartilage
bone
hematopoeietic
(left to right)
157
Identify left to right
macrophages
fibroblast
collagen
158
What is this?
mast cell
159
What are these?
plasma cells
160
what type of carilage is this?
what is top line pointing to
hyaline
chondrocyte
161
hyaline cartilage identify top to bottom
line 1
line 2
line 3
line 4
line 5
cline 6
line 7
isogenous groups
nucleus
territorial matrix
lacunar rim
type Ii collagen
RER
interterriortiral matrix
162
What type of cartilage is this?
what is line 1
line 2
line 3
elastic
perichondrium
chondrocytes
elastic fibers
163
What type of cartilage is this?
Fibrocartilage
164
165
All cartilage is
avscular
166
