Articular System

Question 1

How are joints classified?

Answer 1

1) fibrous joints 2) cartilaginous joints 3) synovial joints

Question 2

What are the 3 types of fibrous joints?

Answer 2

Sutures gomphosis syndesmosis

Question 3

Give an example of syndesmosis joint?

Answer 3

In inferior tibia fibula joint
Tibia and fibula are connected by interosseous ligament

Question 4

Give an example of gomphosis joint?

Answer 4

In teeth
Teeth are connected to their sockets by periodontal ligament

Question 5

Give an example of sutures joint?

Answer 5

In skull
Bones of the skill are connected by sutures ligament

Question 6

Define joints

Answer 6

Joint is the contact between 2 bones or more

Question 7

Define the 2 types of cartilaginous joints?
Compare between primary cartilaginous joint and secondary cartilaginous joint.

Answer 7

1) primary cart.→ temporary (disappears after ossification)
→ at the end of long bones
→ immobile joint
→ structure: plate of hyaline cartilage between the epiphysis and diaphysis of children

2) secondary cart. → permanent
→ midline (invertebral discs)
→ limited mobility
→ bones are covered by hyaline cartilage and separated by white fibrocartilaginous disc

Question 8

Define the synovial joint

Answer 8

→ freely mobile
→ present mostly in the limbs
→ cavity filled with synovial fluid and covered by a fibrous capsule.
→ surrounded by synovial membrane ( secretes synovial fluid)
→ particular surfaces are covered by particular cartilage

Question 9

What are synovial joint formed of?

Answer 9

Fibrous capsule - articular cartilage - joint cavity- synovial membrane - synovial fluid- ligaments - intra-articular structures

Question 10

What is the function of synovial fluid?

Answer 10

Lubricates the cartilage and reduces erosion of articular cartilage
Helps nutrition of particular cartilage

Question 11

What is the characteristics of articular cartilage?

Answer 11

Smooth and lubricated by synovial fluid
Has no vessels or nerves
Takes nutrition from synovial fluid

Question 12

What are the structures inside the synovial cavity ( intra-articular structure)?

Answer 12

Particular fibrocartilaginous disc _ menisci (semilunar cartilage) - ligaments - tendons

Question 13

Example for particular fibrocartilaginous disc?

Answer 13

Temporomandibular joint

Question 14

What is the function of ligaments?

Answer 14

They support & strengthen the joint
→ capsular, extracapsular, intracapsular ligaments

Question 15

Example for menisci

Answer 15

Two semiluner plates of fiber cartilage inside the knee joint

Question 16

What are the factors affecting the stability of he joint?

Answer 16

1) shape and fitting of articular surfaces.
2) thickness and elasticity of the capsule
3) position and strength of the ligaments
4) strength of muscles surrounding the joint

Question 17

What are the factors affecting the range of motion?

Answer 17

1) tension of ligament surrounding the joint
2) contraction of the antagonistic muscles
3) approximation and contact of the soft tissues around the joint

Question 18

Define Hilton’s law.

Answer 18

The nerve supply to a muscle acting on a specific joint gives a branch to supply this joint and another branch to supply the skin covering this joint

Question 19

Is there a nerve supply to the joint?

Answer 19

Sensory nerves that supply the joint are called articular nerves → they are sensitive to pain position & movement of the joint.