3. Connective Tissue

Question 1

What are the main classes of connective tissue?

Answer 1

1. CT Proper - ligaments and tendons
2. Supporting CT - bone
3. Fluid CT - blood

Question 2

Which germinal layer is all CT derived from?

Answer 2

The MESODERM only

Question 3

What is CT made up of?

Answer 3

Cells which create, maintain, or breakdown the ECM and ECM which allow the tissue to bear weight and withstand tension and trauma.

Question 4

What is ground substance composed of?

Answer 4

Water and two main groups of soluble proteins: cell adhesion proteins (fibronectin, osteonectin) and proteoglycans (contain GAGs which take up water)

Question 5

How are collagen fibres formed?

Answer 5

3 chains of AAs wind to form collagen molecule, which are modified into tropocollagen in the ECM. Assemble into fibrils and bundled into thick collagen fibres. Requires vitamin C

Question 6

What are the other 2 fibres present in the ECM?

Answer 6

Elastic (secreted by fibroblasts) and reticular (type III collagen, allow more give than collagen fibres)

Question 7

What are the types of CT Proper?

Answer 7

Loose - fibres < ground substance

Dense - fibres > ground substance

Question 8

What is the function of bone marrow?

Where is it found?

Answer 8

Produces all 3 types of blood cells + lymphocytes to support immune system.
Red BM found in heads of long bones, skull, vertebrae and ribs
Yellow BM found in middles of long bones

Question 9

What characterises leukaemia?

Answer 9

High numbers of immature/abnormal WBCs.

Bruising, anaemia, reduced clotting, increased infections

Question 10

What is the function of heparin?

How does it work?

Answer 10

Anticoagulant

Removes GAGs from proteoglycans to make the ECM more less viscous (thinner)