Connective Tissue Histology

Question 1

4 basic classifications of tissue

Answer 1

• Muscle
• Epithelia
• Connective tissue
• Nervous tissue

Question 2

What does connective tissue have roles in?

Answer 2

• Structural support
• Tensile strength
• Binding tissues together
• Immune defence
• Metabolism and energy storage
• Cushioning
• Elasticity

Question 3

What is connective tissue proper?

Answer 3

Non-specialised connective tissue

Question 4

2 forms of connective tissue proper

Answer 4

• Loose connective tissue
• Dense connective tissue

Question 5

Components of connective tissue

Answer 5

• Cells
• Extracellular matrix

Question 6

What makes up the extracellular matrix?

Answer 6

• Ground substance
• Fibres

Question 7

What is the ground substance made of?

Answer 7

• Glycosaminoglycans
• Proteoglycans
• Water

Question 8

What are the fibres in the extracellular matrix?

Answer 8

• Collagen
• Elastin
• Reticular

Question 9

What is the main cell type in non-specialised connective tissue?

Answer 9

Fibroblasts

Question 10

What is the function of fibroblasts?

Answer 10

Produce and maintain the extracellular matrix

Question 11

Fixed cells in connective tissue and their functions

Answer 11

• Fibroblast
• Fibrocytes (inactive fibroblasts)
• Adipocytes (fat cells)
• Macrophages (phagocytic)

Question 12

What are wandering connective tissue cells?

Answer 12

Immune cells that can move into connective tissue when required

Question 13

Examples of wandering connective tissue cells (and their function)

Answer 13

• Plasma cells (produce antibodies)
• Eosinophils (consume foreign substances)
• Neutrophils (phagocytic)
• Lymphocytes
• Mast cells (inflammatory, histamine production)

Question 14

What glycosaminoglycan often is the backbone of ground substance?

Answer 14

Hyaluronic acid

Question 15

What do glycosaminoglycans contain that affects pH and what is the effect?

Answer 15

• Negative side chains
• Makes it acidic

Question 16

Benefits of ground substance being hydrophilic and binding water

Answer 16

• Makes it strong to resist compressive forces
• Provides volume
• Allows good diffusion

Question 17

General structure of elastin

Answer 17

Thin and branched

Question 18

What is the precursor of elastin and how is it turned into elastin?

Answer 18

• Tropoelastin
• Polymerised to elastin

Question 19

What is required for the formation of elastin?

Answer 19

Fibrillin scaffold

Question 20

What is fibrillin?

Answer 20

Glycoprotein produced by fibroblasts

Question 21

Function of elastin

Answer 21

Allows stretch and recoil to maintain shape

Question 22

Where are elastin fibres found in the body?

Answer 22

• Skin
• Ears
• Arteries
• Lungs
• Bladder

Question 23

Structure of collagen

Answer 23

• Triple alpha helix
• Thick with no branching

Question 24

Types of collagen (and where they are found)

Answer 24

• Type I (bone, skin, tendons, ligaments)
• Type II (cartilage)
• Type III (reticular fibres)
• Type IV (basement membrane)

Question 25

Function of reticular fibres

Answer 25

Form framework of organs/glands and blood vessels

Question 26

What is basement membrane?

Answer 26

Specialised extracellular matrix that usually underlies epithelial cells

Question 27

Where else can basement membrane be found?

Answer 27

- Surrounding some cells - Separating 2 sheets of cells

Question 28

Make up of loose connective tissue (no. of cells, amount of ground substance, no. and arrangement of fibres)

Answer 28

- Many cells - Mostly ground substance - Some fibres, loosely + randomly arranged

Question 29

Function(s) of loose connective tissue

Answer 29

- Binds structures - Diffusion

Question 30

Make up of dense irregular connective tissue (no. of cells, amount of ground substance, arrangement of fibres)

Answer 30

- Fewer cells - Less ground substance - More fibres, randomly arranged

Question 31

Function(s) of dense irregular connective tissue

Answer 31

Withstand pressure from different directions

Question 32

Make up of dense regular connective tissue (no. of cells, amount of ground substance, arrangement of fibres)

Answer 32

- Fewer cells - Less ground substance - More fibres, arranged in parallel

Question 33

Function(s) of dense regular connective tissue

Answer 33

Resist forces in one direction (tensile strength)

Question 34

Types of adipose tissue

Answer 34

- White - Brown

Question 35

Lipid droplet arrangements in the different adipose tissues

Answer 35

- White = 1 big droplet - Brown = multiple small droplets

Question 36

Where are the different adipose tissues typically found?

Answer 36

- White = adults - Brown = newborns, adult around kidney

Question 37

What is brown adipose tissue rich in and what is its function?

Answer 37

- Mitochondria and capillaries - Thermogenesis

Question 38

Symptoms of Ehlers Danlos Syndrome and what causes it?

Answer 38

- Fragile, extra elastic skin and hypermobile joints - Mutation of type I, III or V collagen

Question 39

Symptoms of Marfan's Syndrome and what causes it?

Answer 39

- Long digits + arms and tissues rich in elastic fibres (eg. aorta - risk of aneurysm) affected - Mutation of fibrillin

Question 40

Symptoms of osteogenesis imperfecta and what causes it?

Answer 40

- Brittle bones/malformations - Mutation of type I collagen

Question 41

Symptoms of chondrodysplasia and what causes it?

Answer 41

- Cartilage defects and joint abnormalities - Mutation of type II collagen