8. Connective Tissues

Question 1

What are the functions of the connective tissue blood?

Answer 1

Liquid tissue that’s for gas transport and immune defence functions.

Question 2

What are the functions of the connective tissues cartilage and bone?

Answer 2

Structural functions.

Question 3

What are six functions of connective tissues?

Answer 3

Provide substance and form to the body and organs. Provide a medium for diffusion of nutrients and wastes. Attach muscle to bone and bone to bone. Provide a cushion between tissues and organs. Defend against infection. Aid in injury repair.

Question 4

What are the two components of connective tissue?

Answer 4

Cells and extra cellular matrix, which consists of ground substance and fibres (collagen, reticular or elastic).

Question 5

Name three ways in which connective tissues difference from each other?

Answer 5

The type of cells they contain, the abundance and density of their cells and the constitution of their extra cellular matrix (ground substance composition and fibre type, abundance and arrangement).

Question 6

What are the two embryonic connective tissues?

Answer 6

Mesenchyme and mucous connective tissue.

Question 7

What are the two tissues classified as proper/ regular connective tissue?

Answer 7

Loose/ areolar or dense (irregular or regular).

Question 8

What are six specialised connective tissues?

Answer 8

Adipose tissues, blood, cartilage, bone, lymphatic tissue and haemopoietic tissue.

Question 9

How do mesenchymal cells look with H and E dye?

Answer 9

Tapered cells due to cytoplasmic processes. Abundant, viscous ground substance looks like lots of white.

Question 10

What do mucous connective tissues look like under the microscope?

Answer 10

Capillaries bearing red bleed cells, specialised ground substance takes up a lot of intercellular space. The mesenchymal cells are spindle-shaped.

Question 11

What are proteoglycans?

Answer 11

Monomers that have a core protein to which around 100 glycosaminoglycan units are joined.

Question 12

What is the function of proteoglycans?

Answer 12

They have a high density of negative charge so attract water and form a hydrated gel.

Question 13

What proportion of the whole body protein content does collagen take up?

Answer 13

1/4 to 1/3, it’s the commonest protein in our body.

Question 14

What is gelatin?

Answer 14

Hydrolysed collagen.

Question 15

How many type of collagen are there?

Answer 15

At least 28.

Question 16

What is the most widely distributed type of collagen?

Answer 16

Type I, 90% of all collagen. Fibrils aggregate into fibres and fibre bundles.

Question 17

Give a detail of type II collagen and two places it is present in.

Answer 17

Their fibrils don’t form fibres. It’s present in hyaline and elastic cartilage.

Question 18

Where can type I collagen be found?

Answer 18

In tendons, capsules of organs and skin dermis.

Question 19

What is reticulin?

Answer 19

Type III collagen. It’s fibrils form fibres around muscle and nerve cells and within lymphatic tissue and organs.

Question 20

Where can type IV collagen be found?

Answer 20

Unique form in basal lamina of basement membrane.

Question 21

What is the structure of type I collagen?

Answer 21

An amino acid chain where every third amino acid of the a-chain is glycine.
There are three a-chains, forming a triple helix.
Each collagen molecule is 300nm long and 1.5nm wide.
Each fibril is composed of staggered collagen molecules, periodic banding appears ever 68nm.

Question 22

What are elastic fibres mare of?

Answer 22

Elastin and fibrillin. The elastin enfolds and is surrounded by fibrillin.

Question 23

What is Marfan’s syndrome?

Answer 23

An autosomal dominant disorder where the expression of the fibrillin gene is abnormal so the elastic tissue is abnormal.

Question 24

What are they symptoms of Marfan’s syndrome?

Answer 24

Sufferers are abnormally tall, have arachnodactyly (long fingers), have frequent joint dislocation and are at risk of catastrophic aortic ruptures.

Question 25

Where can loose connective tissue be found?

Answer 25

In the lamina propria between the krypton of Lieberkühn and the colon.

Question 26

What type of connective tissue is the dermis?

Answer 26

Dense irregular connective tissue.

Question 27

What is dense irregular connective tissue?

Answer 27

Bundles of collagen densely packed but irregularly arranged so they can be orientated in multiple directions.

Question 28

Where can dense regular connective tissue be found?

Answer 28

In the tendon. Collagen bundles lie in parallel in line with the tensile forced exerted by the muscle.

Question 29

What lies in between collagen bundles and muscle fibre filaments?

Answer 29

Sarcolemma.

Question 30

What is the purpose of fibroblasts in connective tissues?

Answer 30

To synthesis and secrete ground substance and fibres that lie within the ground substance. They’re important for wound healing and are cells primarily responsible for formation of scar tissues.

Question 31

What are macrophages?

Answer 31

Phagocytise cells and antigen presenting cells that help with degradation of foreign organisms and cell debris.

Question 32

What are mast cells?

Answer 32

Cells that contain lots of granules. Granules contains heparin, histamine and substances that attract eosinophils and neutrophils.

Question 33

What’s the difference between white and brown adipose tissue in terms of lipid droplets?

Answer 33

White adipose tissues have the multiple lipid droplets fuse to form a single large droplet which displaces the other cells contents to the cell periphery but brown adipose tissue have the multiple lipid droplets stay separate.

Question 34

What is the appearance of white adipose tissue cells with H and E staining?

Answer 34

They look empty as all the cell contents are at the periphery.

Question 35

What is the appearance of brown adipose tissue with H and E staining?

Answer 35

many lipid droplets with a central nucleus.

Question 36

What is the appearance of neutrophils under a light microscope?

Answer 36

They have five lobes to their nucleus.

Question 37

What is the appearance of red blood cells under a light microscope?

Answer 37

Round discs.

Question 38

What is the appearance of resting lymphocytes under a light microscope?

Answer 38

Most of the cytoplasm is filled by the nucleus.

Question 39

What is connective tissue?

Answer 39

A huge continuum throughout the body linking together muscle, nerve and epithelial tissue in a structural way but also providing support in metabolic and physiological pathways.