Joints and Dislocations

Question 1

Where is cartilage located?

Answer 1

Where mobility is required at articulations (joints)

Question 2

What causes movement of bones?

Answer 2

Skeletal muscles contracting

Question 3

What are the 3 types of joint?

Answer 3

Fibrous, cartilaginous, synovial

Question 4

What is the compromise that has to be made in joints?

Answer 4

Between mobility and stability

Question 5

What is the relative stability and mobility of fibrous joints?

Answer 5

Limited mobility and stable

Question 6

What are two types of fibrous joint?

Answer 6

Syndesmoses and sutures

Question 7

What do syndesmoses do and what is an example?

Answer 7

Unite bones with a fibrous sheet e.g. interosseous membrane

Question 8

Which of sutures and syndesmoses are more stable?

Answer 8

Sutures

Question 9

Where are sutures found?

Answer 9

Between the bones of the skull

Question 10

What are fontanelles?

Answer 10

Wide sutures in the neonatal skull (anterior, posterior, lateral)

Question 11

What do fontanelles allow?

Answer 11

Frontal, parietal, temporal and occipital bones to slide over each other, making the head smaller for birth

Question 12

What is the mobility/stability compromise in cartilaginous joints?

Answer 12

Fairly limited motility and relatively stable

Question 13

What are synchondroses?

Answer 13

Primary cartilaginous joints

Question 14

Where are synchondroses (primary cartilaginous joints) found?

Answer 14

In bones joined by hyaline cartilage e.g. epiphyseal growth plate

Question 15

What are symphyses?

Answer 15

Secondary cartilaginous joints (fibrocartilage)

Question 16

What is an example of a secondary cartilaginous joint?

Answer 16

Intervertebral disc

Question 17

What occurs when a primary cartilaginous bone slips?

Answer 17

Slipped femoral epiphysis

Question 18

What occurs when a secondary cartilaginous bone slips?

Answer 18

Slipped disc

Question 19

What can a slipped disc do?

Answer 19

Compress neural structures (spinal cord or spinal nerves)

Question 20

What is the outer part of an intervertebral disc?

Answer 20

Outer fibrous annulus fibrosus (fibrous ring)

Question 21

What is the inner part of an intervertebral disc?

Answer 21

Inner soft nucleus propulsus

Question 22

Where are synovial joints found?

Answer 22

Two or more bones articulating with each other

Question 23

What secretes synovial fluid?

Answer 23

Deeper synovial membrane layer

Question 24

What are synovial joints supported by?

Answer 24

Ligaments

Question 25

What are the 5 types of synovial joint?

Answer 25

Pivot, ball and socket, plane, hinge, biaxial

Question 26

What does a pivot joint allow and give an example?

Answer 26

>45 degree shaking of the head rotation- atlanto-axial joint

Question 27

What does a plane joint allow and give an example?

Answer 27

Minimal movement in one plane- acromioclavicular joint

Question 28

What does a hinge joint allow and give an example?

Answer 28

Reasonable range of movement in one plane- elbow joint

Question 29

What does a biaxial joint allow and give an example?

Answer 29

Reasonable range of movement in one plane and less in another- metacarpophalangeal joint

Question 30

What does a ball and socket joint allow and give an example?

Answer 30

Good ranges of multi axial movement- hip joint

Question 31

What is the mobility/stability compromise in synovial joints?

Answer 31

Fairly mobile- not so stable

Question 32

What does subluxation mean?

Answer 32

Reduced area of contact between articular surfaces

Question 33

What is a dislocation?

Answer 33

Complete loss of contact between articular surfaces

Question 34

What type of joint is the TMJ?

Answer 34

Synovial

Question 35

What is the TMJ an articulation between?

Answer 35

Mandibular fossa and articular tubercle of temporal bone and the head of the mandibular condyle

Question 36

What happens in a dislocation of the TMJ?

Answer 36

The head of the condylar process of the mandible becomes stuck anterior to the temporal bone tubercle

Question 37

What will a dislocation of the TMJ show physically?

Answer 37

Mouth wide open and cannot be shut

Question 38

Dislocation of the TMJ can be bilateral or unilateral, how can you tell the difference?

Answer 38

If the chin is remaining in the midline, it is bilateral

Question 39

Do the joints have good sensory nerve supply or not?

Answer 39

Yes, they do

Question 40

What are the 4 sensations detected by the sensory receptors of the joint nerves?

Answer 40

pain, touch, temperature and proprioception

Question 41

What is a big risk of dislocations?

Answer 41

Damage arteries and compromise blood supply distal to the joint