Lesson 6

Question 1

They consists of heterogeneous populations of cells that are separated from each other by a substantial amount of intercellular substance mostly secreted by the constituent cells.

Answer 1

Connective Tissue

Question 2

These two intercellular substance both comprise the connective tissue matrix.

Answer 2

both fibrous and amorphous

Question 3

It holds, binds, and supports other tissues of the body.

Answer 3

connective tissue

Question 4

What is the origin of all connective tissues?

Answer 4

They are derived from the mesoderm.

Question 5

What are the stem cells of connective tissue?

Answer 5

Mesenchymal cells.

Question 6

What separates connective tissues from non-connective tissues?

Answer 6

The basal lamina.

Question 7

What are the four criteria for classifying connective tissue?

Answer 7

1. Predominant cell type or types.
2. Type of fibrous components in the matrix.
3. Number of fibers in a unit area of the matrix.
4. Orderliness of the matrix components.

Question 8

What are the two main components of the intercellular material in connective tissue?

Answer 8

Fibers and ground substance.

Question 9

What are the three types of fibers in connective tissue?

Answer 9

1. Collagenous.
2. Reticular.
3. Elastic.

Question 10

What is the nature of ground substance in connective tissue?

Answer 10

Amorphous.

Question 11

What are the two categories of cells in connective tissue?

Answer 11

Resident cells and transient/migrant cells.

Question 12

What are examples of resident cells in connective tissue?

Answer 12

1. Mesenchymal cells.
2. Reticular cells.
3. Fibroblast (fibrocytes).
4. Macrophages.
5. Pericytes.
6. Fat cells.
7. Mast cells.
8. Foreign body giant cells.

Question 13

What are examples of transient/migrant cells in connective tissue?

Answer 13

1. Plasma cells.
2. Pigment cells.
3. Lymphocytes.
4. Monocytes.
5. Neutrophils.
6. Eosinophils.
7. Basophils.

Question 14

What is another constituent of connective tissue besides intercellular material and cells?

Answer 14

Tissue fluid

Question 15

What are the two main components of the intercellular material in connective tissue?

Answer 15

Fibers and ground substance

Question 16

What is the nature of the fibers in connective tissue?

Answer 16

Glycoprotein in nature

Question 17

What is the staining property of collagenous fibers with H&E stain?

Answer 17

Pink-staining

Question 17

Which cells produce collagenous fibers?

Answer 17

Fibroblasts

Question 17

What produces the fibers in connective tissue?

Answer 17

Connective tissue cells.

Question 18

What is the most numerous type of fiber in connective tissue?

Answer 18

Collagenous fibers.

Question 19

How many different types of collagen are currently known?

Answer 19

15 types (e.g., Type I, II, III, IV).

Question 19

What is the structural hierarchy of collagenous fibers? (How it is formed)

Answer 19

Tropocollagen molecules → Microfibrils → Fibrils → Fibers.

Question 20

Which techniques are used to stain reticular fibers effectively?

Answer 20

Silver (argyrophilic) and PAS (Periodic Acid-Schiff) techniques.

Question 21

What type of collagen forms reticular fibers?

Answer 21

Type III collagen.

Question 22

What is the arrangement of reticular fibers?

Answer 22

They are arranged in a network.

Question 23

What is the diameter of reticular fibers?

Answer 23

0.5–2.0 µm.

Question 24

What cells produce elastic fibers?

Answer 24

Fibroblasts and smooth muscle cells of blood vessels.

Question 25

What protein composes the core of elastic fibers?

Answer 25

Elastin.

Question 26

What is the appearance of elastic fibers in a stretched state?

Answer 26

Long, thin, straight, and branched fibers.

Question 27

What molecular bonds are responsible for the elasticity of elastin?

Answer 27

Desmosine cross-links.

Question 28

What surrounds the core of elastin in elastic fibers?

Answer 28

A sheath of microfibrils composed of glycoprotein fibrillin.

Question 29

What is the nature of ground substance in connective tissue?

Answer 29

Amorphous material in a viscous gel form.

Question 30

They are meant to bind great quantities of water and facilitate the movement of metabolites and waste products.

Answer 30

ground substance

Question 31

What are the **three main components of ground substance?**

Answer 31

Glycosaminoglycans, proteoglycans, and glycoproteins.

Question 32

What is the structural nature of glycosaminoglycans?

Answer 32

Negatively charged, long rod-like chains of repeating disaccharides.

Question 33

Negatively charged, long rod-like chains of repeating disaccharides.

Answer 33

glycosaminoglycans

Question 34

Bind large quantities of water and give tissue greater resistance to compression forces.

Answer 34

glycosaminoglycans

Question 35

What are the sulfated glycosaminoglycans?

Answer 35

1. Keratin sulfate, 1. heparin sulfate, 1. heparin, 1. chondroitin 4-sulfate, 1. chondroitin 6-sulfate, 1. and dermatan sulfate.

Question 36

What is the non-sulfated glycosaminoglycan?

Answer 36

Hyaluronic acid.

Question 37

A protein core with glycosaminoglycans covalently bonded to it.

Answer 37

Proteoglycans

Question 38

What is an example of a proteoglycan?

Answer 38

Aggrecan.

Question 39

Produces the gel state of the extracellular matrix and serves as a barrier to the diffusion of aqueous substances.

Answer 39

aggrecan

Question 40

is a protein that's part of basement membranes throughout the body. It's also known as heparan sulfate proteoglycan 2 (HSPG2).

Answer 40

Perlecan

Question 41

Facilitate the attachment of cells to the extracellular matrix.

Answer 41

cell adhesive glycoproteins

Question 42

What are the major types of adhesive glycoproteins and their locations?

Answer 42

1. **Fibronectin**: Throughout the extracellular matrix. 1. **Laminin:** Basal laminae. 1. **Entactin and Tenascin:** Embryonic tissues. 1. **Chondronectin:**Cartilage. 1. **Osteonectin**: Bone.

Question 43

They **possess binding sites for components of extracellular matrix** as well as for integrin molecules of the cell membrane **thus facilitate the attachment of cells** to the extracellular matrix

Answer 43

Glycoproteins