Tendon and Ligament Biology

Question 1

What does a tendon connect?

Answer 1

Muscle to bone

Question 2

What is the function of a tendon?

Answer 2

Transmit muscle force with minimal elongation

Question 3

Which body tissue has the highest tensile strength?

Answer 3

Tendon

Question 4

What cells make up a tendon?

Answer 4

Tenocytes and fibroblasts

Question 5

Describe the organisation of a tendon

Answer 5

Made up of a tertiary fibre bundle which consists of:

• Secondary fascicles
• Primary fascicles
• Collagen fibres
• Collagen fibrils

Endotenon - encloses each fascicle
Epitenon - encloses all fascicles
Paratenon - encloses the epitenon

Question 6

What is the composition of tendon?

Answer 6

Collagen

• type I (95%)
• type III and type V (5%)

Elastin

Proteoglycans

Fibrocartilage

Question 7

What is the properties of collagen?

Answer 7

Provide tensile strength

Question 8

What is the property of elastin?

Answer 8

Provides elasticity and stores energy during movement

Question 9

What are the properties of proteoglycan?

Answer 9

Regulate collagen fibril size and helps with resistance by binding with water

Question 10

How do the cells of the tendon change at the enthesis?

Answer 10

Cells at the enthesis are more fibrocartilaginous

Question 11

What are the specialised regions of the tendon?

Answer 11

Epiphysis

Wrap around regions

Myotendinous junctions

Question 12

What is golfer’s elbow?

Answer 12

Medial epicondylitis

Question 13

What is tennis elbow?

Answer 13

Lateral epicondylitis

Question 14

What does a ligament connect?

Answer 14

Bone to bone

Question 15

What is the function of a ligament?

Answer 15

Holds joint together

Supply proprioceptive information

Question 16

What is the composition of a ligament?

Answer 16

Collagen

• Type I (90%)
• Type III (10%)

Proteoglycans

Elastin

Water

Question 17

What are the most common sports related ligament injuries?

Answer 17

MCL - better repair capacity

ACL - repair capacity is poor

Question 18

What is the meniscus?

Answer 18

Cartilage between bones that act like a shock absorber

Question 19

What is articular cartilage?

Answer 19

Cartilage on the bones that tolerate pressure

Question 20

What is the synovium?

Answer 20

Produces synovial fluid that lubricates tissue surface

Question 21

Which two types of cell form tissue?

Answer 21

Parenchymal cells - functioning cells of tissue

Support cells - commonly termed connective tissue

Question 22

What 4 macromolecules does extracellular matrix consist of?

Answer 22

Collagen

Elastin

Proteoglycans

Glycoproteins

Question 23

What is collagen?

Answer 23

Main structural protein in connective tissue

Aggregate to produce filaments, fibrils or meshwork to support ECM

Question 24

What substances strengthen the cross links between collagen?

Answer 24

Lysine

Hydroxylysine

Question 25

Which collagen types are fibrillar and provide mechanical strength?

Answer 25

Types: I, II, III, V, XI

Question 26

Which collagen types are fibril-associated and link collagens to each other?

Answer 26

Types: IX, XII, ...

Question 27

Which collagen types are sheet forming and anchoring?

Answer 27

Type IV - forms meshworks in basal laminae Type VII - connects basal laminae in skin to underlying connective tissue

Question 28

Which collagen type is transmembranous and function as adhesion receptors?

Answer 28

Type XIII