Lecture 6: Connective Tissue

Question 1

Three types of connective tissue

Answer 1

Embryonic
Adult
Special

Question 2

Two types of embryonic ct

Answer 2

Mesenchyme

Mucous

Question 3

4 types of adult connective tissue

Answer 3

Loose
Dense
reticular
adipose

Question 4

Three types of special connective tissue

Answer 4

Cartilage
Bone
Blood

Question 5

6 functions of connective tissue

Answer 5

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

Question 6

5 Clinical relevancies of connective tissue

Answer 6

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

Question 7

Two components of ct

Answer 7

Cells

Matrix

Question 8

Two types of cells of Ct

Answer 8

resident

transient

Question 9

Three components of the matrix of the ct

Answer 9

Fibers
Ground substance
Tissue fluid

Question 10

Resident cells

Answer 10

• embryonic mesenchyme cells

- Always there

Question 11

Examples of resident cells

Answer 11

Fibroblasts
reticular cells
adipocytes
mesenchymal
macrophages
mast cells

Question 12

Transient cells

Answer 12

• Hematopoietic stem cells

- Come and go

Question 13

Examples of transient cells

Answer 13

plasma cells
leukocytes
neutrophils
eosinophils
basophils
lymphocytes

Question 14

Fibroblasts form

Answer 14

collagenous, elastic, and reticular fibers of the matrix

Question 15

Macrophages

Answer 15

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

Question 16

Macrophages origin

Answer 16

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

Question 17

Macrophages may be named by

Answer 17

location

ex. osteoclasts in bone
ex. kupffer cells in liver

Question 18

Degranulation of mast cells causes

Answer 18

symptoms of allergy

Question 19

Collagen fibers

Answer 19

white, very tensile and strong, do not stretch

Question 20

Elastic fibers

Answer 20

Yellow, weak, and elastic, stretch and recoil

Question 21

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

Answer 21

Collagenous fibers

Question 22

Collagen fiber structure

Answer 22

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

Question 23

Collagen fibers represent ____% dry weight in humans

Answer 23

30

Question 24

4 Primary Types of Collagen Fibers

Answer 24

• 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)

Question 25

4 main types of collagen synthesis

Answer 25

Fibroblasts Chondroblasts Osteoblasts Odontoblasts

Question 26

Procollagen

Answer 26

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

Question 27

What is an important cofactor in collagen synthesis?

Answer 27

Vitamin C

Question 28

3 Properties of collagen

Answer 28

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

Question 29

Elastic fibers

Answer 29

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

Question 30

Size of elastic fibers

Answer 30

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

Question 31

Where can elastic fibers be found (7)

Answer 31

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

Question 32

Reticulum

Answer 32

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

Question 33

Collagen type 3 is synthesized by

Answer 33

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

Question 34

The reticular ct serves as

Answer 34

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

Question 35

Deficiency of collagen type III

Answer 35

Results in fragile skin syndromes

Question 36

What is ground substance composed of?

Answer 36

Glycosaminoglycans (GAGS) Proteoglycans Glycoproteins

Question 37

Properties of ground substance molecules allow for

Answer 37

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

Question 38

Common macromolecules of GAGs

Answer 38

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

Question 39

4 types of structural glycoproteins

Answer 39

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

Question 40

Proteoglycans

Answer 40

- 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 )

Question 41

Structural glycoproteins

Answer 41

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

Question 42

Proteoglycans: GAGs: | Where is hyaluronic acid found?

Answer 42

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

Question 43

Proteoglycans: GAGs: | Where is chondroitin sulfate found?

Answer 43

cartilage, arteries, skin, and cornea

Question 44

Proteoglycans: GAGs: | Where is keratin sulfate found?

Answer 44

cornea, cartilage, bone

Question 45

Proteoglycans: GAGs: | Where is dermatan sulfate found?

Answer 45

Skin, tendons, sclera, and lungs

Question 46

Proteoglycans: GAGs: | Where is heparin sulfate found?

Answer 46

arteries and lung

Question 47

Connective tissue fluid

Answer 47

- 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

Question 48

Edema

Answer 48

Abnormal accumulation of tissue fluid

Question 49

Mesenchyme

Answer 49

- 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

Question 50

Loose connective tissue

Answer 50

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

Question 51

Dense connective tissue

Answer 51

Irregular and regularly arranged Densely packed fibers Strong tissue

Question 52

Dense connective tissue

Answer 52

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

Question 53

Adipose connective tissue is formed by

Answer 53

Adipocytes: cells with basement membrane

Question 54

Functions of adipocytes (2)

Answer 54

- 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

Question 55

What makes something adipose tissue?

Answer 55

Adipocytes outnumber other cell types

Question 56

Unilocular

Answer 56

White fat

Question 57

Multilocular

Answer 57

Brown fat

Question 58

Purpose of white fat

Answer 58

energy storage insulation Endocrine: leptin

Question 59

Purpose of brown fat

Answer 59

heat generation

Question 60

Brown adipose cells have many

Answer 60

mitochondria

Question 61

Lipomas

Answer 61

Very common benign tumors generated by unilocular adipocytes