Connective Tissue 2

Question 1

Define connective tissue?

Answer 1

tissue that connects, supports, binds or seperates other tissues and organs

Question 2

Where do connective tissue originate from?

Answer 2

embryonic mesenchyme - tissue developing mainly from the mesoderm

Question 3

Define CT properties that distinguish it from other primary tissues?

Answer 3

1. originates from the mesenchyme 2. different degrees of vascularity/blood flow 3. mostly composed of non-living material

Question 4

CT consists of?

Answer 4

cells + extracellular matrix

Question 5

Extracellular matrix consists of?

Answer 5

protein fibres + ground substance

Question 6

What is ground substance?

Answer 6

a complex of anionic, hydrophilic proteoglycans, GAGs, Multi-adhesive glycoproteins

Question 7

Name cells of the CT?

Answer 7

1. fibroblasts + fibrocytes 2. adipocytes 3. macrophages 4. mast cells 5. plasma cells 6. other leukocytes

Question 8

Describe structure and function of fibroblasts + fibrocytes?

Answer 8

1. most common cell type in CT with mesenchymal origin 2. produce and maintain most of the extracellular components

Question 9

Describe structure and function of adipocytes?

Answer 9

1. mesenchymal origin 2. specialized for cytoplasmic storage of lipids

Question 10

Describe structure and function of macrophages?

Answer 10

1. bone marrow derived - part of mononuclear phagocyte system 2. phagocytosis of extracellular matrix components and debris

Question 11

Describe structure and function of mast cells?

Answer 11

1. contain secretory granules 2. release of many bioactive substances e.g. histamine

Question 12

Describe structure and function of plasma cells?

Answer 12

1. B-lymphocyte derived 2. synthesis of antibodies

Question 13

Describe structure and function of other leukocytes?

Answer 13

form a population of wandering cells in CT

Question 14

Name the fibres of CT?

Answer 14

1. collagen 2. reticular 3. elastic

Question 15

Describe collagen fibres?

Answer 15

1. made of collagen 2. key element of all CT + epithelial basement membranes + external laminae of muscle and nerve cells 2. is strong and resistant to normal shearing + tearing forces

Question 16

Describe reticular fibres?

Answer 16

1. made mainly of collagen III 2. forms extensive network of thin fibres that support most cells e.g. reticular lamina of basement membrane

Question 17

Describe elastic fibres?

Answer 17

1. made of elastin 2. allows tissues to be stretched or distended and return to their original shape

Question 18

What is ground substance?

Answer 18

highly hydrated transparent complex mixture of glycosaminoglycans + proteoglycans + multi adhesive glycoproteins

Question 19

3 classes of macromolecules in ground substance?

Answer 19

glycosmaminoglycans + proteoglycans + glycoproteins

Question 20

Function of ground substance?

Answer 20

fills the space between cells and fibers in connective tissue acting as a lubricant and a barrier to the penetration of invaders because of its viscous state

Question 21

What are the types of CT?

Answer 21

1. connective tissue proper 2. embryonic connective tissue 3. specialized connective tissue

Question 22

How is CT proper classified?

Answer 22

amount of collagen fibres present

Question 23

What are the types of CT proper?

Answer 23

1. loose or areolar CT 2. dense irregular CT 3. dense regular CT

Question 24

Describe loose/areolar CT?

Answer 24

1. structure: well vascularized + consists of thin and looslely arranged collagen and elastic fibres + has abundant cells of various types and abundant ground substance 2. function: Support microvasculature, nerves, and immune defense cells 3. location: lamina propria, mesentry, subcutaneous tissue, omentum

Question 25

Describe irregular CT?

Answer 25

1. structure: few cells (typically fibroblasts) + little ground substance + abundant collagen fibres interweaving in various directions 2. function: protects and supports organs - resists tearing 3. location: found in regions under considerable mechanical stress + where protection is given to ensheathed organs e.g. dermis, submucosa of GIT, organ capsules (testes, periosteum + perichondrium)

Question 26

Describe dense regular CT?

Answer 26

1. structure: closely packed collagen bundles arranged according to a definite pattern + little ground substance + few fribroblasts that are aligned in parallel to fibres 2. Adapted to resist prolonged or repeated stresses exerted in the one direction + Provide strong connections within musculoskeletal system; strong resistance to force 3. location: ligaments, tendons

Question 27

Difference between dense irregular and dense regular CT?

Answer 27

dense irregular CT has collagen in various direction and has less collagen and dense regular CT has collagen in a parallel structure and has more collagen

Question 28

Name types of embryonic connective tissue?

Answer 28

1. mesenchyme 2. mucoid CT

Question 29

Name specialized connective tissue?

Answer 29

1. reticular CT 2. adipose CT 3. bone, cartilage and blood

Question 30

Name specialized tissues?

Answer 30

1. elastic 2. reticular 3. mucoid 4. adipose

Question 31

Describe elastic tissue?

Answer 31

specialized dense CT formed by elastic fibres - appears yellow in color

Question 32

Describe reticular tissue?

Answer 32

loose CT made up of reticular fibres - forms supporting networks for cells

Question 33

Describe mucoid tissue?

Answer 33

has abundant jelly-like ground substance rich in hyaluronan, sparse fibroblasts & collagen - embryonic type of CT found mainly in umbilical cord & fetal organs

Question 34

Describe adipose tissue?

Answer 34

aggregation of fat cells - found subcutaneously in most parts of the body

Question 35

What are the functions of CT?

Answer 35

1. holds together structures e.g. skin, muscles, blood vessels 2. forms a framework that supports the cellular elements of organs e.g. spleen 3. provides a tight covering for deeper structures + maintains shape 4. store of nutrition - adipose tissue 5. helps the body fight against invading foreign substance - cells of the immune system 6. laying down collagen fibres for wound repair + regenration - fibroblasts