Histology

Question 1

What are the components of Connective Tissue?

Answer 1

Cells

Extracellular Matrix

Question 2

What makes up the Extracellular Matrix?

Answer 2

Water
Protein fibers
Ground substance

Question 3

Connective tissue is derived from what embryonic germ layer?

Answer 3

Mesoderm

Question 4

Cells commonly found in Connective Tissue

Answer 4

Fibroblasts
Mesenchymal Cells
Macrophages
Mast Cells
Plasma Cells
Adipocytes

Question 5

Histological appearance of fibroblasts

Answer 5

Spindle-shaped
Pink
Prominent nucleus and nucleolus
Well-developed Golgi apparatus
Surrounded by pink ECM

Question 6

Macrophage VS Monocyte?

Answer 6

Macrophage - resident phagocytic cell in connective tissue. Plays a role in turnover of protein fibers, clearing of debris, and in immune response.

Monocyte - the precursor of macrophages. Found in the blood

Question 7

What is a mast cell?

Answer 7

Blue round cell with multiple dark secretory granules
Similar in apearance to Basophils
Release Histamine and initiate Immediate Hypersensitivity
Located at sentinel sites near blood vessels

Question 8

3 major kinds of protein fibers in CT?

Answer 8

Collagen (most common)
Elastin
Reticular fibers

Question 9

3 kinds of collagen and their examples

Answer 9

1. Fibril-forming
2. Sheet-forming
3. Linking

Question 10

Explain the process of collagen fiber formation

Answer 10

1. Production of procollagen a chains
2. Hydroxylation of proline and lysine by Hydroxylase
3. Glycosylation of hydroxylysine residues
4. Formation of triple helix, stabilization by cysteine disulfide bonds
5. Packaging, transport, and secretion of trimeric procollagen molecule
6. Procollagen peptidase clips off terminal globular peptides
7. Aggregation and formation of fibers
8. Collagen cross-links formed via lysyl oxidase

Question 11

Locations of the following types of collagen: 
Type I
Type II
Type III
Type IV

Answer 11

I - skin, bone, tendons
II - cartilage
III - blood vessels (reticular)
IV - basal laminae

Question 12

Function of collagenase

Answer 12

Degradation of collagen

Question 13

Differentiate:
Ehler-Danlos Type IV
Ehler-Danlos Type VI
Ehler-Danlos Type VII

Answer 13

Type IV - defective collagen Type III - blood vessel rupture

Type VI - defective lysin hydroxylation - increased skin elasticity, eyeball rupture

Type VII - defective procollagen peptidase - subluxation of joints

Question 14

Defect in Scurvy

Effect?

Answer 14

Hydroxylation of proline and lysine residues (Vitamin C dependent)

Gum bleeding, hemorrhages

Question 15

Defect in Osteogenesis imperfecta

Effect?

Answer 15

Altered gene for Type I collagen

Weak bones

Question 16

Defect in Marfan Syndrome

Answer 16

Fibrillin Gene

Aortic Aneurysms

Question 17

2 components of an elastin fiber

Answer 17

Fibrillin

Elastin

Question 18

What is elastase?

Answer 18

Enzyme for degradation of elastin

Question 19

What is desmosine?

Answer 19

Cyclic structure cross-linking elastin fibers