Joint Mechanics

Question 1

3 types of fibrous joints (synarthrosis)

Answer 1

Sutures
Syndesmosis
Gomphosis

Question 2

2 types of cartilaginous joints (amphiarthrosis)

Answer 2

Hyaline (syncondrosis)

Fibrocartilage (symphysis)

Question 3

3 types of synovial joints (diarthroses)

Answer 3

Spheroid

Hinge

Condylar

Question 4

What type of joint is united by dense fibrous tissue? What is movement dependent on?

Answer 4

Fibrous joints; movement depends on length of fibers uniting bones

Question 5

_________ are a type of fibrous joint held together by several layers of strong CT; extremely tight and provide little movement

Answer 5

Sutures

Question 6

What are the 2 types of suture edges associated with suture joints?

Answer 6

Squamous type = edges overlap

Serrate type = edges interlock

Question 7

________ are a type of fibrous joints where bones are united by a sheet of fibrous tissue; may be a ligament or fibrous membrane

Give examples and degree of movement to be expected

Answer 7

Syndesmosis

Examples: IO membrane between radius and ulna, tibiofibular syndesmosis, tympanostapedial syndesmosis

Movement can be slight to considerable, depending on distance between the bones and degree of flexibility of the uniting fibrous tissue

Question 8

____ type of fibrous joint between tooth and bone in its alveolus

What anchors the tooth?

Answer 8

Gomphosis

Fibrous tissue of periodontal ligament anchors tooth

Question 9

What are secondary cartilaginous joints?

Answer 9

Surfaces of articulating bones are covered with hyaline cartilage and bones are united by strong fibrous CT and/or fibrocartilage

Question 10

Distinguishing features of synovial joints

Answer 10

Synovial membrane

Joint cavity

Articular cartilage - hyaline

Articular capsule

Question 11

Articular cartilage in synovial joints is usually ______ type, although matrix contains many collagenous fibers. There is no _____ or ______ supply, so they are nourished by synovial fluid which obtains nutrients from capillaries in synovial membrane

Answer 11

Hyaline

Blood vessel; nerve

Question 12

Is the synovial membrane vascular or avascular?

Answer 12

Vascular!

Question 13

Accessory ligaments are either:

_______ - part of their fibrous capsules

_________ - separate from the fibrous capsules

Answer 13

Intrinsic

Extrinsic

Question 14

Articular ______ are present in synovial joints where the articulating surfaces are incongruous

Answer 14

Discs

Question 15

_______ = fibrocartilaginous ring that deepens the articular surface for the bones

Answer 15

Labrum

Question 16

Types of synovial joint

Answer 16

Plane
Hinge (ginglymus)
Ball and socket (spheroidal)
Pivot (trochoid)
Condyloid & ellipsoid
Saddle (sellar)

Question 17

Classify the AC joint, proximal tibiofibular, intercarpal, and SC joints

Answer 17

Plane joints

Question 18

AA joint

Radioulnar joint

Answer 18

Pivot joints

Question 19

_________ law = nerves supplying a joint also supply muscles moving the joint and skin covering attachments of these muscles

Answer 19

Hilton’s

Question 20

Where in the joint are nerve endings found?

Answer 20

Articular capsule

Question 21

_______ law == bone is increased where needed and reabsorbed where it is not

Answer 21

Wolff’s

[increased density/hypertrophy related to increase stresses; decreased density related to disuse or aging]

Question 22

With repeated high stresses to cartilage, what disease may occur?

Answer 22

Degenerative joint disease

Question 23

What effect does physical training have on ligaments and tendons?

Answer 23

Become stronger/stiffer due to increase in number and quality of collagen cross-links

Question 24

3 basic forms of arthritis

Answer 24

Osteoarthritis

Inflammatory

Traumatic

Question 25

Osteoarthritis most commonly affects what joints?

Answer 25

Hips

Knees

Question 26

The fibrous articular capsule is very sensitive, but the synovial membrane is not. Joint pain is often poorly localized and so pain described is usually referred pain. What principle explains this?

Answer 26

Hilton’s law

Question 27

_________ = early degenerative change of articular cartilage d/t loss of proteoglycans which unmasks collagen fibers and icnreases water in chondrocytes

Answer 27

Fibrillation

[affected cartilage becomes dull with yellowish color - looks like ground glass!]

Question 28

________ = complete loss (ulceration) of articular cartilage accompanied by a thickening of subchondral bone (osteosclerosis)

Answer 28

Eburnation

[exposed bone takes on ivory like appearance - hard and polished; lesion is permanent]

Question 29

“Joint mice” are fragments of cartilage and/or bone floating free in synovial fluid which have detached from the subchondral bone. What conditions is this seen in?

Answer 29

Osteochondromatosis

Degenerative joint diseases (especially osteochondrosis dissecans)