HE8 & 9 Connective tissues Flashcards Preview

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Flashcards in HE8 & 9 Connective tissues Deck (40):
1

Important functions of CT?

Structure (bones, cartilage, ligaments), Movement (ligaments). Support glands/organs. Store fat.

1. Attracts water
2. Exchanges blood/lymph, fluid.
3. initial site of response to injury/host defense

2

Composition of CONNECTIVE TISSUES?

Cells separated throughout an Extracellular matrix ECM.

3

Composition of GROUND SUBSTANCE?

1. Glycosaminoglycans (GAGS)
2. Proteoglycans (PG's)- > protein core w/ GAG's
3. Multiadhesive glycoproteins (MGP's)

4

Composition of GAG's

1. repeating units of DISACCHARIDES (not mono or tri)!
2. NEGATIVELY CHARGED

and most are SULFATED (hyaluronin not sulfated)

5

Primary function of glycosaminoglycans and proteoglycans? Function in BM?

Hydration of ECM (attract/hold water in the CT)
-
important for movement of cells/materials & est. concentration gradient.

Basement membrane= CHARGED BASED FILTRATION BARRIER

6

Proteoglycan agregates structure and function

Glycosaminoglycans bound to a core protein forms a hydration unit of PROTEOGLYCAN.

Proteoglycans are linked by "linker proteins" to HALURONIN protein core

Gives ECM gel-like state, resisting compression to act like "SHOCK ABSORBERS"

7

GAG's, PG's, PG agregates at LM

GAG's/PG's high negative charge stain w/ basophilic BLUE basic dyes

HE STAIN= BLUE/PURPLE
PAS= MAGENTA/PINK

8

Multiadhesive glycoprotein (MGP) 5 Structures/ 4 functions.

Remember picture of MGP's parallel under plasma membrane bound to green INTEGRINS which go through plasma membrane and attached to actin.


1. Fibronectin
2. Laminin
3. Tenascin
4. Osteopontin
5. Enactin/Nidogen

1. ECM assembly/structure
2. Adhesion (fibroblast to ECM)
3. Mechanosensation (FOCAL ADHESION)
4. Regulate cell migration

9

Fibronectin, Laminin, or Osteopontin are examples of what?

Multiadhesive glycoproteins

10

Elastic fiber distribution. STAIN? Structure?

1. Dermis-skin
2. Heart valves
3. Walls of large arteries (AORTA)
4. Lungs (alveolar walls)

Ocrein used to distinguish between collagen and elastic fibers.

ELASTIN core with FIBRIN microfibrils

11

What 4 cells make COLLAGEN?
Where does Fibril formation occur?

What 3 categories? and what type Collagen in each category?

1. Fibroblasts
2. Epithelial cells
3. Smooth muscle cells
4. Schwann cells (PNS)

MADE OUTSIDE THE CELL!
- Tropocollagen-->Fibril

1. Fibrillar (I,II,III)
2. Network forming (IV)
3. Anchoring (VII)

12

AT TEM what periodicity seen in Collagen?

68nm

13

68nm periodicity relates to what kind of cell?

Collagen FIBRILS (type 1,2,3). as a result of the orderly staggered assembly of tropocollagen into fibrils (overlap and holes).

14

Which type of molecule forms Fibrils, Fibers, and Bundles? Where found?

WHAT STAIN>

TYPE 1 COLLAGEN.
-sclera
-dentin
-orgain/joint capsules
-scar tissue

(Dermis, hypodermis, fascia, bones, ligaments, joints, tendons)

HE=pink bundles
TRICHROME-blue green

15

_______ found in cartilage and vitreous humor and stain______ whith _______stain. What happens if there is alot of PG's present with it?

Type 2 Collagen
(restrains PG aggregates from expanding)

stains light pink with HE stain. if high PG's blue masks over light pink type 2 collagen

16

LM looks like smooth fiberglass finish (blue, light pink) with large eye looking bubbles. TEM looks like unfinished rough fiberglass like on back side of a tub/shower

Type 2 collagen fibrils

17

____is first type of collagen in embryo and during adult injury repair and is replaced with ______. When heavily _____ the fibers are referred to as _______. They are often stained ______ with _____.

TYPE 3 COLLAGEN, TYPE 1 COLLAGEN, GLYCOSYLATED, RETICULAR FIBERS, BLACK, SILVER STAIN.

18

What type of collagen fibers form a delicate lattice that supports organs that :
1. filter blood/lymph (liver,spleen,lymph),
2. rich vasculature (endocrine organs),
3. proliferating cells (bone marrow)

Reticular fibers of Type 3 collagen.
REINFORCE/SUPPORT SMALL BLOOD VESSEL WALLS

found supporting:
Adipocytes
Smooth muscle fibers
peripheral nerve fibers
-walls of blood/lymph vessels

19

What connective tissue supports/anchors epithelium to BL and is part of the filtration barrier?

Structure? Location? Function?

TYPE IV COLLAGEN- Basal Lamina- FILTRATION
1. no fibrils or periodicity
2. flat sheets of type IV MONOMERS

Attaches Epithelium to BL

20

What connective tissue anchors BL to RL?

Type VII Collagen- Anchoring FIBRILS

RL ADHESION!

21

Problems in what type of collagen cause HEMATURIA, BLISTERS, BRUISING, TENDON RUPTURE, OCULAR SHAPE CHANGE?

Type IV--- BL FILTRATION- blood in urine
Type VII---RL ADHESION- blisters
Type III---- Supports small blood vessels- bruising
Type I------ bundles DiRCT- tendon injury
Type II----- Restrains PG's in vitreous - eye deformities

22

PRIMARY FIBER DEFECTS & PATHOLOGY:
Type 1,2,3,4,7

I. Osteogenesis imperfecta
II. Achondrogenesis II
III. Ehlers-Danlos IV
IV. Alport's syndrome
VII. Kindler's Syndrome

23

Alport's syndrome-
Kindlers syndrome-
Ehlers-Danlos IV
Achondrogenesis II
Osteogenesis imperfecta

I. Osteogenesis imperfecta
II. Achondrogenesis II
III. Ehlers-Danlos IV
IV. Alport's syndrome
VII. Kindler's Syndrome

24

Where is CT derived from ? Where is that derived from?

Mesenchymal cells-- from mesoderm and Neural Crest
Adults have mesenchymal-like cells in CT

25

What is the name for a neoplastic mesenchymal cell of adipocyte that becomes malignant? for a benign fibroblast?

Fibrosarcoma
lipoma

26

Tissue macrophages and mast cells are examples of what kind of cells in the CT.

Resident cells- long lived- mesenchymal like- renewal

27

What is the principal resident CT cell? LM TEM

FIBROBLASTS- makes all ECM components
LM- long flat cell, basophilic cytoplasm.
ECM- protein secreting cell- constitutive
Activated state- lined up next to each other
Quiet state- widely dispersed

28

MYOfibroblasts vs fibroblasts at TEM

Fibroblasts look like protein secreting cell- long flat
Myofibroblasts have bundles of actin filaments (hard to see) but looks more wild like mesenchymal star shape ec.

29

Myofibroblasts vs fibroblasts in wound healing.

Whats myofibroblast NOT involved with? in terms of wound healing*

Fibroblasts (24hrs)- Quick repair- makes initial ECM with TYPE III collagen (later replaced w/ type I).

Myofibroblasts (1week)- repair/active 2nd week- apoptosis, approximates tissues to bring closer together

MYOBLAST NOT INVOLVED WITH ECM REMODELING

30

Histocytes

Monocytes migrate from blood into CT and differentiate into MACROPHAGES (HISTOCYTES)

Macrophage (not monocyte) is considered resident Sentinel cell.

31

TEM LM of Macrophage

nucleus to one side, looks like has wart bubbles all over it
TEM: features of phagocytic cell (lots of storage molecules with different shapes colors and sizes.

32

Multinucleated giant cells (foreign body giant cells)

Macrophages fuse together to attack or wall off large foreign invaders

33

3 secretions of Mast Cells. other secretions?

PROMOTES INFLAMMATION
Heparin (GAG)- anticoagulant

Histamine- (increases vascular permeability, smooth muscle contraction, mucus production)

WBC chemotactic factors

Leukotrienes (sm contraction) & cytokines- PROMOTES INFLAMMATION.

Releases from granules

34

Where are mast cells found? what antibody receptor?

Skin, Respiratory, GI. IgE

35

Multilocular fat-

Brown fat- for thermal heat generation

36

Transient cells- derived, lifespan, function

from bone marrow (elsewhere), short lived, WBC's Plasma cells, injury, inflammation, immunity

37

Where are plasma cells derived? Function?

B-lymphocytes make plasma cells for Antibody production (iG's) immunoglobulins

38

LM: tear shaped eccentric nucleus, clock face/cartwheel patter, lighter in middle (negative golgi-pale center)

Plasma cell

39

RETICULAR LAMINA- what kind of collagen?

Reticular fibers (type III)
Anchoring fibers (type VII)

40

Where are mesenchymal cells found?

Ground substance