Bones and Joints

Question 1

What is endochondral ossification?

Answer 1

A cartilage is formed as a precursor on which new bone is laid down

Question 2

What is intramembranos ossification?

Answer 2

The direct laying down of bone into the primary connective tissue, no intermediate cartilage

Question 3

What is the diaphysis?

Answer 3

The shaft of a long bone

Question 4

What is the metaphysis?

Answer 4

The wide portion of a long bone between the epiphysis and narrow diaphysis

Question 5

What is the periosteum?

Answer 5

A dense layer of vascular connective tissue enveloping the bones except at the surface of the joints

Question 6

What is avascular necrosis?

Answer 6

Death of bone due to interruption of blood supply

Question 7

What is a joint?

Answer 7

An articulation between two or more bones

Question 8

What are the structural classifications of joints?

Answer 8

Fibrous
Cartilaginous
Synovial

Question 9

What is another name for fibrous joints?

Answer 9

Fixed or immovable joints, because they do not move

Question 10

Give an example of a fibrous joint?

Answer 10

Joints of the skull

Question 11

What cartilage is found at synovial joints?

Answer 11

Articular cartilage

Question 12

What is a bursa?

Answer 12

A sack lined with synovial membrane

Question 13

What is a tendon sheath?

Answer 13

An elongated bursa wrapped around a tendon

Question 14

What is the function of the bursa?

Answer 14

Function of a bursa is to facillitate the movement and reduce friction between moving parts

Question 15

What is Hilton’s law?

Answer 15

The nerves supplying the joint capsule also supply the muscles moving the joint and the skin overlying the insertions of these muscles

Question 16

What is a planar joint?

Answer 16

Articulating surface is flat or slightly curved

Gliding or sliding movements

Question 17

What is a hinge joint?

Answer 17

Uniaxial movement, like a door.

Pulley shaped: Convex surface of one bone fits into a concave surface of another

Elbow or knee

Question 18

Pivot joint

Answer 18

Uniaxial movement

Rounded or pointed surface of one bone articulates within ring formed by the concavity of another bone and a fibrous ligament

Proximal radio-ulnar joint, atlantoaxial joint

Question 19

What is a saddle joint?

Answer 19

One bone is saddle shaped, the other bone resembles the legs of the rider

Flexion, extension, adduction, abduction

Examples 1st carpometacarpal joint

Question 20

What is a ball and socket joint?

Answer 20

Ball like surface of one bone fits into cup like surface of another

Question 21

What factors affect joint stability?

Answer 21

Structure and shape of articulating bones

Strength of joint ligaments

Arrangement of muscles and tone

Question 22

What are the effects of ageing on the joints?

Answer 22

Decreased production of synovial fluid

Thinning of articular cartilage

Shortening of ligaments and decreased flexibility

Degenerative changes

Question 23

What are the X-ray findings of OA on an X ray?

Answer 23

Osteophytes

Joint space narrowing

Bone Cysts

Subarticular sclerosis

Question 24

What are the X-ray features of Rheumatoid arthritis?

Answer 24

Narrowing of joint space

Periarticular osteopenia

Juxta-articular bony erosions

Subluxation and gross deformity