Connective Tissue

Question 1

What are the 4 tissue types?

Answer 1

Epithelium, connective, muscle, nervous

Question 2

What is the structure of the ECM?

Answer 2

Formed by the cells of the connective tissue. Separates and holds the cells in place. Mediates the exchange of nutrients and waste, and transmits electrical signals.

Question 3

What are the contents of the ECM? What are their individual makeups/ roles?

Answer 3

Collagen fibres (great tensile strength), elastin fibres (Coiled structure helps with ability to stretch), ground substance (transparent, gel-like material).

Question 4

How is ground substance adapted for its function?

Answer 4

Made up of large molecules called glycoaminoglycans (GAGs). Hydrophilic (90% water) - high water content and inflexible molecules mean good at resisting compressive forces.

Question 5

Name some cell types found within the ECM

Answer 5

Fibroblasts (least specialised - secrete collagen and ground substance)
Adipocytes (fat cells)
Immune cells (macrophages, mast cells, plasma cells)

Question 6

What is a tendon?

Answer 6

A type of fibrous connective tissue. It is dense and regular, and consists of tightly packed collagen fibres in the same direction.

Question 7

What cells are responsible for maintenance and restoration of tendon?

Answer 7

Tendocytes

Question 8

What type of fibres do tendons contain?

Answer 8

Collagen type 1 and elastin

Question 8

What type of fibres does cartilage contain?

Answer 8

Collagen type 2

Question 8

What is the difference between tendons and ligaments?

Answer 8

Tendons = connect bone to muscle (tender meat falls off bone)
Ligaments = connect bone to bone. Fibrils slightly less orientated than in tendons.

Question 9

What are the 3 types of cartilage?

Answer 9

• Hyaline (glassy appearance, most common, weakest)
• Fibrocartilage (Found in region undergoing tension and compression. Collagen bundles between layers. Strongest)
• Elastic cartilage (Found in elastic regions that return to shape - eg epiglottis and larynx. Many elastin fibres - strong and flexible)

Question 10

Does brittle material deform?

Answer 10

No - it has a high failure strength

Question 11

Does rigid and tough material deform?

Answer 11

Yes it deforms a little bit and can absorb a lot of energy.

Question 12

Does compliant material deform?

Answer 12

Yes deforms easily under low loads.

Question 13

What is Wolff’s law?

Answer 13

Bone is laid down where it is needed and reabsorbed where it isn’t.

Question 14

How does cartilage respond to an increased load (e.g., exercise)?

Answer 14

• Increase size and number of chondrocytes
• Increase ECM
  Excessive loading can cause degradation however.

Question 15

How do tendocytes within tendons respond to an increased load (e.g., exercise)?

Answer 15

• Increase number of fibroblasts
• Increase collagen synthesis
• Increase tendon cross section.