Joint Structure & Function

Question 1

What is a joint?

Answer 1

point of contact between two or more bones, cartilage and bones, or teeth and bones.

Question 2

What is the study of joints

Answer 2

Arthrology

Question 3

What are the 3 main types of joint?

Answer 3

fibrous
cartilaginous
synovial

Question 4

What joints are solid and which are cavitated? (have a cavity)

Answer 4

Solid is fibrous and cartilaginous

Cavitated is synovial

Question 5

What is an example of a fibrous joint?

Answer 5

Sutures of the skull

Question 6

What is an example of a cartilaginous joint?

Answer 6

Pubic symphysis
Epiphyseal growth plate
Intervertebral disc

Question 7

What are the bones held together by in a fibrous joint?

Answer 7

Articulating bones held together by fibrous connective tissue

Question 8

How much movement occurs at a fibrous joint?

Answer 8

Little or no movement

Question 9

What happens if the fibrous joint suture ossifies?

Answer 9

Synostosis - an ossified suture, immovable

Question 10

What is a syndesmosis?

Answer 10

Syndesmosis - sheet of fibrous tissue (interosseous membrane) between bones

Question 11

Where is a syndesmosis found?

Answer 11

Between radius and ulna or between tibia and fibula

Question 12

What movement does the syndesmosis allow?

Answer 12

radius and ulna - allows pronation and supination

Question 13

What holds your teeth in the mandible/maxilla socket?

Answer 13

Gomphosis - cone-shaped peg fits into a socket. e.g. teeth

Question 14

How much do the cartilaginous joints move?

Answer 14

Little or no movement

Question 15

What makes up a cartilaginous joint/how are bones attached?

Answer 15

Fibrocartilage (tough) or hyaline cartilage (smooth)

Question 16

What is symphysis?

Answer 16

Cartilage joint in fibrous cartilage fibrocartilage

Question 17

Where is symphysis found? and why?

Answer 17

Where we need more movement - pubic symphysis, IV discs

Question 18

What is the syndchrondosis? Examples

Answer 18

Cartilage joint - hyaline cartilage, only present in childhood, at epiphyseal growth plate and costochondral joints

Question 19

What are the costochondral joints?

Answer 19

Between ribs and sternum, syndchrondosis, hyaline cartilage, become more brittle with age

Question 20

What are the majority of the joints in the body?

Answer 20

Synovial

Question 21

How much can the synovial joints move?

Answer 21

Freely moveable but ranges between different joints

Question 22

What is the fibrous capsule?

Answer 22

Holds synovial fluid in place, goes around the bone and joint

Question 23

What lines the fibrous capsule?

Answer 23

Synovial membrane which makes the synovial fluid, made up of endothelial cells made up of GAG making fluid gloopy

Question 24

Where is there loose connective tissue in a synovial joint?

Answer 24

Between the fibrous capsule and the synovial membrane, filled with blood vessels

Question 25

What is the role of the articular cartilage?

Answer 25

Caps the ends of the bones forming the joint and gives smooth slippery surface to work with synovial fluid giving friction-less free movement

Question 26

What is the articulating cartilage made up of?

Answer 26

Hyaline cartilage

Question 27

What is an arthogram?

Answer 27

Iodine /contrast dye injected to see joint space and bursae

Question 28

What is the ECM of hyaline cartilage made up of?

Answer 28

Deeper layer merges via a calcified layer with the subchondral bone. 80% water Collagen type II Proteoglycans

Question 29

What do the properties of hyaline cartilage depend upon?

Answer 29

ECM composition

Question 30

What is the function/properties of articulating cartilage?

Answer 30

Hyaline cartilage: Smooth, slippery and very low coefficient of friction Elastic, resilient structure that acts as a shock absorber to protect underlying bone

Question 31

Is the hyaline cartilage calcified?

Answer 31

No apart from very deep layer which merges with the subchondral bone?

Question 32

Why do joints appear as a gap on x-rays?

Answer 32

Black space is articular cartilage which is not seen on an x-ray

Question 33

What else do some most synovial joints contain?

Answer 33

accessory ligaments and articular discs (menisci).

Question 34

What do ligaments do?

Answer 34

Ligaments connect bone to bone Help to stabilise and hold joint together Joined to outer fibrous capsule

Question 35

What do articular discs do?

Answer 35

Articular discs modify shape of joint surfaces | Help maintain stability of joint, and direct flow of synovial fluid to areas of greatest friction.

Question 36

Where is the articular capsule?

Answer 36

surrounds joint. Encloses synovial cavity, uniting articulating bones.

Question 37

What are the two layers of the articular capsule? What do they do?

Answer 37

Outer fibrous capsule (may contain ligaments). | Inner synovial membrane (secretes lubricating and joint nourishing synovial fluid).

Question 38

What is the cause of osteoarthirits?

Answer 38

Loss of articulating cartilage

Question 39

What are the 6 types of synovial joints?

Answer 39

Planar, Hinge, Pivot, Ellipsoidal, Saddle, Ball & Socket

Question 40

What movements can planar joints do?

Answer 40

Gliding movements (side to side and back and forth)

Question 41

Examples of planar joints

Answer 41

Intercarpals and intertarsals

Question 42

How does a hinge joint form?

Answer 42

Convex surface of one bone fitting into concave surface of another bone

Question 43

What movements are in a hinge joint?

Answer 43

Flexion and extension, single plane

Question 44

Examples of a hinge joint?

Answer 44

elbow, knee, Interpharyngeal

Question 45

Examples of a pivot joint

Answer 45

Proximal radio-ulnar joint (annular ligament) | Atlas rotating around the axis

Question 46

How does a pivot joint form

Answer 46

Round/pointed surface of one bone fitting into a ring formed by another bone or ligament

Question 47

What movement occurs at pivot joints?

Answer 47

Rotational, pronation and supination in proximal radio-ulnar

Question 48

What is another name for the ellipsoidal joint?

Answer 48

Condyloid joint

Question 49

How does a condyloid form?

Answer 49

condyle of one bone fits into cavity of another bone

Question 50

What are the movements of the condyloid joint?

Answer 50

Flexion, extension, adduction, abduction, circumduction

Question 51

What is an example of a condyloid joint?

Answer 51

Carpals and radius

Question 52

Which joints are saddle joint?

Answer 52

Carpal-metacarpal of the thumb | carpal is trapezium

Question 53

How does a saddle joint form?

Answer 53

Saddle shaped bone and other is rider

Question 54

What movements can a saddle joint do?

Answer 54

Flexion-extension Abduction-adduction Circumduction

Question 55

How does a ball and socket joint form?

Answer 55

Ball shaped surface of one bone fits into cup like depression of the other

Question 56

What movements are in the ball and socket joint?

Answer 56

flexion, extension, adduction, abduction, circumduction

Question 57

What are some examples of a ball and socket joint?

Answer 57

Shoulder and hip