Connective Tissue 1: Connective Tissue Proper

Question 1

What is the origin of all connective tissue?

Answer 1

The mesoderme

Question 2

What are the types of connective tissue?

Answer 2

Proper
Cartilage
Adipose
Bone
Blood

Question 3

What are the three permanent cells of proper connective tissue?

Answer 3

Les mastocytes
Les fibroblastes
Les adipocytes

Question 4

What are the properties of fibroblast?

Answer 4

Main cells of the conjonctif proprement dit
Thin cells with long cytoplasmic extension
They are the Synthesis site for the composants of the extracellular matrix.
They do not have a lame basale

Question 5

In proper connective tissue, what creates the extracellular matrix?

Answer 5

fibroblast

Question 6

What is a rest state for fibroblasts?

Answer 6

When the secretion activity of a fibroblast stops, its cytoplasm contracts and its nucleus condense, resulting in only the spindle-shaped nucleus detected in histological preparations (cannot tell the difference).

This phenotype is called the fibrocyte.

Question 7

What are Myofibroblast?

Answer 7

Contractile Phenotype of fibroblast
Myofibroblasts are important in the repair of injuries and wound healing.

Question 8

TRUE or FALSE, Proper Connective tissue contains adipose tissue.

Answer 8

FALSE,

Connective TIssue Proper contains some adipose cells

Here we must remember that they are only part of the connective tissue. This is not to be confused with adipose tissue (see below).

Question 9

What is the role of adipose cells in connective tissue proper?

Answer 9

Synthèse des lipides (liposynthèse)
Réserve d’énergie à long terme (triglycérides)
Libération des lipides sous forme d’acides gras (lipolyse).

Question 10

What are the two types of adipose cells in connective tissue proper and their roles?

Answer 10

Adipocytes Blanc
Réserve énergétique
Isolant thermique
Amortisseur de chocs

Adipocytes Bruns:
très riche en mitochondries -> brown color
It is not functional in adults:
Only in new-borns
Can become active in adults in extreme conditions.

Question 11

What is the role of mastocyte cells in connective tissue proper?

Answer 11

cellules de surveillance et de signalisation ».

Cytoplasme riche en granulations basophiles

Important for reactions in allergic and inflammatory reactions:

Question 12

What are the transitory cells of connective tissue proper?

Answer 12

Macrophages
Leucocytes,
plasmocytes

Question 13

Role of macrophages in connective tissue proper?

Answer 13

They will phagocyte:

Non-selectively

Also will recycle red blood cells

Question 14

Can you identify Leucocytes in connective tissue proper?

Answer 14

Low % in the connective tissue so we cannot really identify them but we can identify Lymphocytes

Question 15

What are plasmocytes in connective tissue proper?

Answer 15

lymphocytes B activés

Synthétise et sécrète des anticorps

Question 16

What does the extracellular matrix consist of in connective tissue proper?

Answer 16

Des fibres (collagène, élastine)
Substance fondamentale

Question 17

Where does collagen come from in connective tissue proper?

Answer 17

It comes from fibroblasts

Question 18

What is the smallest unit of collagen?

Answer 18

tropocollagène -> microfibrille → fibrille → fibre

Question 19

What are the 4 types of collagen and their usual location?

Answer 19

Type I (grosses fibres): tendons, os, peau
Type II (fibrilles fines): cartilages
Type III (fibres de réticuline entrelacées dans un réseau) : ganglions lymphatiques, rate, foie et la moelle osseuse
Type IV: lame basale

Question 20

What type of collagen do we find in skin?

Answer 20

Type 1 collagen

Question 21

What is the main site for lame elastine?

Answer 21

In arteries: We need a lot of elasticity.

Question 22

What is one clinical implication of elastin and where do we find it?

Answer 22

We find it in the extracellular matrix of connective tissue proper

Clinical implication is that Synthèse d’élastine diminue avec l’âge

Question 23

Where do elastic fibers come from in connective tissue proper?

Answer 23

From fibroblasts

Question 24

What creates the substence fondementalle in connective tissue proper?

Answer 24

fibroblasts

Question 25

What are the components of substence fondementalle in connective tissue proper?

Answer 25

Contient des glycosaminoglycanes (GAGs), des protéoglycanes (PGs) et du liquide interstitiel

Glycosaminoglycanes +Proteins = Proteoglycans

Question 26

What are the two kinds of connective tissue proper based on fiber cell quantity?

Answer 26

Tissu conjonctif lâche:
Proportion ‘’équilibrée’’ de fibres et de cellules présentes
Tissu conjonctif dense:
riche en fibres
Contient moins de cellules

Question 27

Where do you usually find Tissu conjonctif lâche?

Answer 27

Usually around epithelial cells

Question 28

What are the types of connective tissue based on fiber orientation?

Answer 28

Tissu conjonctif dense orienté:
Tissu conjonctif dense enchevêtré
Tissu conjonctif réticulé

Question 29

Where do we find tissu conjonctif dense orienté and what is the main type of collagen associated with this?

Answer 29

Usually in Tendons (need to remember)
Collagen Type I (mostly)

Question 30

What kind of collagen fiber do we find around Tissu conjonctif réticulé?

Answer 30

Collagène type III ou fibres réticulaires

Question 31

What cells would you expect to see in Tissu conjonctif dense orienté:?

Answer 31

Not many cells but the ones we see will be fibroblasts.

Question 32

TRUE or FALSE, the fundemental substance will be kind of the same amount across types of connective tissue.

Answer 32

FALSE,
for example in Tissu conjonctif dense orienté: Substance fondamentale très réduite

Question 33

Main cells in Tissu conjonctif dense enchevêtré?

Answer 33

Fibroblasts