2 L8 Cells in Tissues 3

Question 1

What are the 3 key properties of connective tissue and what substances are responsible for each of them

Answer 1

Tensile strength- collagen
Elasticity- elastin
Volume- ground substance

Question 2

4 classifications of connective tissue

Answer 2

Connective tissue proper - Cartilage - Blood - Bones

Question 3

Describe loose connective tissue proper

Answer 3

Open, loose structure
Areolar

Question 4

What are the 3 components of loose CT proper

Answer 4

Areolar, Reticular, Adipose

Question 5

Describe areolar (loose CT proper)

Answer 5

Strong yet cushioning
Underlies epithelium and forms lamina propria

Question 6

Define recticular (loose CT proper)

Answer 6

Supportive mesh Reticular fibres
Supports organs

Question 7

Describe adipose (loose CT proper)

Answer 7

Adipocytes
White- stores energy
Brown- thermoregulation

Question 8

What is the rough proportion of ground substance in dense CT proper

Answer 8

Little ground substance

Question 9

What 2 forms can dense CT proper

Answer 9

Regular and Irregular

Question 10

Describe regular dense CT proper

Answer 10

Parallel fibres (mainly type 1 collagen)
Ligaments, tendons

Question 11

Describe irregular dense CT proper

Answer 11

Non-parallel fibres
Dermis

Question 12

Compare loose and dense CT proper

Answer 12

Dense has a greater proportion of fibres

Question 13

3 types of cartilage

Answer 13

Hyaline - Elastic - Fibrocartilage

Question 14

Describe hyaline cartilage

Answer 14

Smooth, translucent - Few collagen fibres - Found at ends of bones and tracheal rings

Question 15

Describe Elastic cartilage

Answer 15

Elastic and collagen fibres - Found in ear

Question 16

Describe fibrocartilage

Answer 16

Many collagen fibres - Found in cartilaginous joints like meniscus in knee

Question 17

Describe bone

Answer 17

Collagen containing ECM that becomes calcified

Question 18

2 types of bone

Answer 18

Compact and Cancellous

Question 19

What do support cells in the ECM do

Answer 19

Produce the ECM components

Question 20

Where are support cells derived from

Answer 20

Embryological tissue mesenchyme

Question 21

Describe the ratio of ECM to cellular component in mature connective tissue

Answer 21

Predominant ECM and sparse cellular component

Question 22

3 main ECM components

Answer 22

Ground substance - Fibrillar proteins - Adhesion proteins

Question 23

Describe Ground substance

Answer 23

Consists of GAGs and proteoglycans

Question 24

What does ground substance bind to and what does it make

Answer 24

Water - salts - collagen proteins - makes a massive matrix structure

Question 25

Describe what fibrillar proteins do

Answer 25

Fibrillar proteins provide strength and elasticity

Question 26

Describe adhesion proteins

Answer 26

Link fibres, ground substance and cells together

Question 27

What is the structure of GAGs

Answer 27

Long, unbranched polysaccharide chain

Question 28

What is the most common GAG

Answer 28

Hylauronic acid (Hyaluronate) which is a long linear molecule of 2 repeating sugar molecules

Question 29

How are proteoglycans formed

Answer 29

Other GAGs bind covalently to hyaluronic acid and core proteins

Question 30

What are the 2 fibrillar proteins

Answer 30

Collagen and Elastin

Question 31

What do fibrillar proteins provide

Answer 31

Strength and elasticity to tissue

Question 32

Describe collagen

Answer 32

Most abundant protein in body - Found in most support tissues - Secreted by fibroblasts - Stains pink in H & E

Question 33

Collagen structure

Answer 33

Series of twisted protein fibres - Fibres appear banded under microscope due to overlap between triple helices

Question 34

How many types of collagen are there and what causes the differences

Answer 34

28- depends on AA composition, produced by different genes

Question 35

Type 1 Collagen

Answer 35

90% of collagen in body - Makes up ligaments, tendons, bone, skin

Question 36

Type 2 collagen

Answer 36

Cartilage

Question 37

Type 3 collagen

Answer 37

Reticular tissue (forms reticular fibres)

Question 38

Type 4 collagen

Answer 38

Basement membrane

Question 39

Describe elastin

Answer 39

Produced by fibroblasts - Abundant in blood vessels, skin, lungs, elastic cartilage

Question 40

Elastin structure

Answer 40

Elastin protein comprised of short segments - Segments covalently bound to each other to allow stretching and relaxation

Question 41

What are the 2 adhesion proteins

Answer 41

Fibronectin and Laminin

Question 42

What do adhesion proteins do

Answer 42

Mediate interactions between ECM and cell cytoskeleton

Question 43

Describe fibronectin

Answer 43

Dimeric glycoprotein - Binds collagen, proteoglycans and cells - Binds collagen to interns on cell surface

Question 44

Describe Laminin

Answer 44

Binds multiple components of ECM - Forms sheets that make up BM - Binds cells to BM (binds to integrins)

Question 45

True or False- integrins are crucial for both types of cell adhesion

Answer 45

True- crucial in focal adhesions and hemidesmosomes

Question 46

Focal adhesions

Answer 46

Binds cells to ECM

Question 47

Hemidesmosomes

Answer 47

Attaches epithelial cells to BM

Question 48

How do integrins help with cell adhesion

Answer 48

They interact with proteins on both sides of the lipid bilayer e.g. cytoskeleton and ECM adhesion proteins

Question 49

How do support cells bind to ECM

Answer 49

Via focal adhesions

Question 50

What are integrins linked to and how

Answer 50

Intracellular intermediate filaments (cytokeratin) via an electron dense plaque BM by anchoring to filaments composed of laminin