Lecture 6: Connective Tissue Flashcards Preview

First Semester: Microscopic Anatomy > Lecture 6: Connective Tissue > Flashcards

Flashcards in Lecture 6: Connective Tissue Deck (61):
1

Three types of connective tissue

Embryonic
Adult
Special

2

Two types of embryonic ct

Mesenchyme
Mucous

3

4 types of adult connective tissue

Loose
Dense
reticular
adipose

4

Three types of special connective tissue

Cartilage
Bone
Blood

5

6 functions of connective tissue

-Connect
-Suspend/give form/subdivide
-Insulation and storage
-Defend
-Provide nutrition
-Repair and regeneration

6

5 Clinical relevancies of connective tissue

-Trauma/healing
-Inflammation
-Edema
-Vitamin C deficiency
-Tumor terminology/development

7

Two components of ct

Cells
Matrix

8

Two types of cells of Ct

resident
transient

9

Three components of the matrix of the ct

Fibers
Ground substance
Tissue fluid

10

Resident cells

-embryonic mesenchyme cells
-Always there

11

Examples of resident cells

Fibroblasts
reticular cells
adipocytes
mesenchymal
macrophages
mast cells

12

Transient cells

-Hematopoietic stem cells
-Come and go

13

Examples of transient cells

plasma cells
leukocytes
neutrophils
eosinophils
basophils
lymphocytes

14

Fibroblasts form

collagenous, elastic, and reticular fibers of the matrix

15

Macrophages

-Resident phagocytic cell of ct
-Can survive months in tissue
-May be named by located

16

Macrophages origin

From monocytes in blood. Once it enters ct, it is called a macrophage

17

Macrophages may be named by

location
ex. osteoclasts in bone
ex. kupffer cells in liver

18

Degranulation of mast cells causes

symptoms of allergy

19

Collagen fibers

white, very tensile and strong, do not stretch

20

Elastic fibers

Yellow, weak, and elastic, stretch and recoil

21

What are the most numerous fibers in the CT and bone?

Collagenous fibers

22

Collagen fiber structure

Extracellular scleroprotein fibers composed of fibrils usually arranges in bundles of indefinite length

23

Collagen fibers represent ____% dry weight in humans

30

24

4 Primary Types of Collagen Fibers

-Type 1: Resists tensile forces. Found in bone, dentin, tendons.
-Type 2: Resists compression. Forms fibrils found in cartilage
-Type 3: Reticular fibers found in stroma of expandable organs such as spleen, lymph node, liver, CV system, and lymphatics
-Type 4: basement membrane (basal membrane)

25

4 main types of collagen synthesis

Fibroblasts
Chondroblasts
Osteoblasts
Odontoblasts

26

Procollagen

Formed in the fibroblast, cleaved to tropocollagen outside the cell and then assembled into collagen fibrils

27

What is an important cofactor in collagen synthesis?

Vitamin C

28

3 Properties of collagen

-High tensile strength
-Poor shear strength
-Can only stretch 5% of initial length

29

Elastic fibers

Individual branching and anastomosing fibers; pink in H E but not easily detected, more evident with special stain
Yellow in natural color

30

Size of elastic fibers

0.2 - 5 um diameter in loose ct
Up to 12um in elastic ligaments
Can stretch up to 2.5 times original length

31

Where can elastic fibers be found (7)

Aorta artery
Elastic artery
Lungs
Vocal chords
Dermis
Pinna of ear
epiglottis

32

Reticulum

-A fine network formed by reticular fibers
-Can be stained by silver (argentaffin)

33

Collagen type 3 is synthesized by

Reticular cells, liver cells, smooth muscle cells, and skeletal muscle cells

34

The reticular ct serves as

a scaffolding for cells in lymph node, spleen, and bone marrow

35

Deficiency of collagen type III

Results in fragile skin syndromes

36

What is ground substance composed of?

Glycosaminoglycans (GAGS)
Proteoglycans
Glycoproteins

37

Properties of ground substance molecules allow for

1. Binding of water
2. Resisting compressive forces
3. Cell adhesion to fibers
4. Cell migration
5. Barrier to bacterial/venom penetration

38

Common macromolecules of GAGs

-Hyaluronic acid
-Chondroitin sulfate
-Keratin sulfate
-Dermatan sulfate
-Heparan sulfate

39

4 types of structural glycoproteins

-Fibronectin
-Laminin
-Osteonectin (In bone)
-Chondronectin (In cartilage)

40

Proteoglycans

-Formed by covalently linking GAGs to protein core
-May regulate passage of molecules and cells in the intercellular space and in chemical signaling between cells
-Stain with basic dyes if present in high concentrations (hyaline cartilage )

41

Structural glycoproteins

Proteins with attached carbs, help attach cells to each other and to extracellular matrix

42

Proteoglycans: GAGs:
Where is hyaluronic acid found?

Vitreous humor of the eye, synovial fluid, umbilical cord, loose ct, skin, and cartilage

43

Proteoglycans: GAGs:
Where is chondroitin sulfate found?

cartilage, arteries, skin, and cornea

44

Proteoglycans: GAGs:
Where is keratin sulfate found?

cornea, cartilage, bone

45

Proteoglycans: GAGs:
Where is dermatan sulfate found?

Skin, tendons, sclera, and lungs

46

Proteoglycans: GAGs:
Where is heparin sulfate found?

arteries and lung

47

Connective tissue fluid

-Solution of nutrients and dissolved gases derived from plasma
-Bathes matrix and cells with nutrients, aids in removing waste
-Fluid dynamics maintain proper balance
-Lymphatics important in fluid movement and prevention of edema

48

Edema

Abnormal accumulation of tissue fluid

49

Mesenchyme

-Originates from the mesoderm and gives rise to adult ct
-Gel-like due to presence of ground substance, few fibers and star-shaped mesenchymal cells

50

Loose connective tissue

-Ubiquitous
-Loosely arranged fibers
-Cellular constituents vary with location

51

Dense connective tissue

Irregular and regularly arranged
Densely packed fibers
Strong tissue

52

Dense connective tissue

-Inactivated fibroblast = fibrocyte nuclei
-Parallel arranged collagenous fibers
-Very strong, resists tensile forces
-Found in tendons, ligaments, cornea

53

Adipose connective tissue is formed by

Adipocytes: cells with basement membrane

54

Functions of adipocytes (2)

-Energy storage
-Endocrine: adipocytes produce leptin which has a regulatory effect on body fat. Leptin levels are proportional to body fat. It signals to the brain (satiety center) that the body has had enough to eat

55

What makes something adipose tissue?

Adipocytes outnumber other cell types

56

Unilocular

White fat

57

Multilocular

Brown fat

58

Purpose of white fat

energy storage
insulation
Endocrine: leptin

59

Purpose of brown fat

heat generation

60

Brown adipose cells have many

mitochondria

61

Lipomas

Very common benign tumors generated by unilocular adipocytes