M2 L8

Question 1

What is connective tissue?

Answer 1

tissue providing
- general structure
- physical and metabolic support for specialised tissues
- mechanical strength
- fills body spaces

Question 2

key properties of connective tissue

Answer 2

• elasticity (elastin)
• tensile strength (collagen)
• volume (ground substance)

Question 3

what are the 3 types of connective tissue

Answer 3

• connective tissue proper
• cartilage
• bone

Question 4

what are the two types of connective tissue proper

Answer 4

• loose
• dense

Question 5

what are the 3 types of loose connective tissue proper

Answer 5

open looses structure
- areolar
- reticular
- adipose

Question 6

what are the two types of dense connective tissue proper

Answer 6

greater proportion of fibres and little ground substance
- regular
- irregular

Question 7

areolar

Answer 7

• strong yet cushioning
• underlies epithelium, forms lamina propria

Question 8

reticular

Answer 8

• reticular fibres (supportive mesh)
• supports organs

Question 9

adipose

Answer 9

• adipocytes
• white: energy storage
• brown: thermoregulation

Question 10

regular dense

Answer 10

• parallel fibres (mostly type I collagen)
• eg. tendons and ligaments

Question 11

irregular dense

Answer 11

• non-parallel fibres
• eg. in dermis

Question 12

what are the three types of cartilage

Answer 12

• hyaline/ articular
• fibrocartilage
• elastic

Question 13

hyaline cart

Answer 13

• smooth, translucent
• few collagen fibres
• eg. ends of bones, tracheal rings

Question 14

fibrocartilage

Answer 14

• many collagen fibres
• eg. menisci of the knee

Question 15

elastic cart

Answer 15

• elastin and collagen fibres
• eg. ears

Question 16

bone

Answer 16

• calcified collagen containing ECM
  -compact and cancellous

Question 17

what are support cells

Answer 17

• derived from embryonic mesenchyme
• produces and excretes ECM

Question 18

what is the difference between a blast and a cyte

Answer 18

blast is more active
cyte is more mature

Question 19

ECM made of

Answer 19

• ground substance
• fibrillar proteins
• adhesion proteins

Question 20

what does ground substance do?

Answer 20

• compression resistance
• volume
• interact with:
  -> itself
  -> water
  -> collagen
  -> more

Question 21

what is ground substance made of

Answer 21

• glycosaminoglycans (GAGs)
• proteoglycans

Question 22

GAGs

Answer 22

• long unbranching polysaccharides
• hyaluronic acid most common
  -> two repeating sugar molecules
  -> other GAGs attach to hyaluronic via other proteins

Question 23

proteoglycans

Answer 23

• proteins that covalently link to GAGs

Question 24

what do fibrillar proteins do? what are two examples

Answer 24

provide strength (collagen) and elasticity (elastin)

Question 25

collagen

Answer 25

- twisted fibres overlap in triple helices, making it appear striated under microscope - forms fibrils, fibres, sheets - most abundant protein in the body - stained pink by H AND E - secreted by fibroblasts - 28 types -> vary by aa composition -> produced by different genes

Question 26

what are the first four types of collagen

Answer 26

I: - 90% of body collagen - ligaments, tendons, bone, skin II: - cartilage III - reticular IV - basement membrane

Question 27

elastin

Answer 27

- forms fibres and sheets - produced by fibroblasts - abundant in lungs, blood vessels, skin, elastic cartilage - comprised of short segments -> covalently bonded -> allow stretching and elastic recoil

Question 28

what do adhesion proteins do

Answer 28

-link fibres, cells, and ground substance - mediate interactions between cytoskeleton and ECM - glycoproteins

Question 29

fibronectin

Answer 29

- dimeric - binds collagen to cell surface integrins - binds proteoglycans, and cells

Question 30

laminin

Answer 30

- binds multiple components of ECM - forms basement membrane sheets - binds integrins -> binds cells to basement membrane

Question 31

what are two types of cell-matrix adhesions?

Answer 31

- focal adhesions - hemidesmosomes

Question 32

focal adhesions

Answer 32

- cells to ECM - link ECM collagen to cellular protein bound to actin

Question 33

what is mature connective tissue primarily made of

Answer 33

ECM

Question 34

what is the matrix composition and function of connective tissue proper

Answer 34

matrix comp: gel- like ground substance, all three fibre types funct: binding tissue, resist mechanic stress (mostly tension)

Question 35

what is the ECM comp and function of cartilage

Answer 35

ECM: gel-like ground substance, collagen fibres, elastin in some funct: resist compression, cushions and supports body structures

Question 36

what is the ECM comp and function of bone?

Answer 36

ECM: gel-like ground substance hardened with calcium salts funct: rigidness that resists tension and compression, support