Joint Structure and Function

Question 1

Describe what is meant by ‘structural classification of joints’

Answer 1

Based on the presence or absence of a synovial joint cavity and the type of connecting tissue that is present e.g. fibrous, cartilaginous or synovial

Question 2

Define ‘synarthroses’

Answer 2

Immovable joint

Question 3

Define ‘amphiarthroses’

Answer 3

Partially movable joint

Question 4

Define ‘diarthroses’

Answer 4

Freely movable joint

Question 5

What are ‘fibrous joints’?

Answer 5

No synovial cavity, articulating bones held by fibrous connective tissue (little movement)

Question 6

Give 3 examples of fibrous joints.

Answer 6

Teeth, interosseous membrane between radius and ulna (and tibia and fibula), and skull sutures

Question 7

Define ‘synostosis’

Answer 7

Ossified immovable structure (i.e. sutures of skull)

Question 8

Define ‘syndesmosis’

Answer 8

Sheet of fibrous tissue between bones (i.e. interosseous membrane)

Question 9

Define ‘gomphosis’

Answer 9

Cone shaped peg that fits into socket (i.e. teeth)

Question 10

What are ‘cartilaginous joints’?

Answer 10

No synovial cavity, articulating bones connected by fibrocartilage or hyaline cartilage (little movement)

Question 11

Give 3 examples of cartilaginous joints.

Answer 11

Pubic symphysis, intervertebral discs and epiphyseal growth plate

Question 12

Define ‘synchrondosis’

Answer 12

Two bones connected by hyaline cartilage (e.g. epiphyseal growth plate)

Question 13

Define ‘symphysis’

Answer 13

Two bones connected by disc of fibrocartilage (e.g. intervertebral discs and pubic symphysis)

Question 14

What are ‘synovial joints’?

Answer 14

A synovial joint cavity exists between articulating bones (freely movable)

Question 15

What is an ‘arthrogram’?

Answer 15

Iodine injected into joint cavity and illustrates the cavity and interconnected bursae so it can be seen on x-ray

Question 16

Describe the articulating cartilage at synovial joints.

Answer 16

Hyaline cartilage covers the bone ends and is an elastic, resilient structure which acts as a shock absorber to protect the underlying bone

Question 17

Why is hyaline cartilage a good cover for articulating bone surfaces?

Answer 17

Has smooth, slippery and low friction surface and a level of elasticity and shock absorption.

Question 18

Describe the structure of the articulating capsule in synovial joints.

Answer 18

Articulating capsule surrounds joint and encloses synovial cavity (uniting two bones). There is the outer fibrous capsule (may contain ligaments) and the inner synovial membrane (secretes synovial fluid - nourishing and lubricating)

Question 19

What is meant by osteoarthritis?

Answer 19

The degeneration of the articulating cartilage (hyaline or fibrocartilage depending on joint)

Question 20

Name the 6 types of synovial joint

Answer 20

Hinge, pivot, plantar, ellipsoidal (condylar), ball and socket and saddle

Question 21

Describe a plantar joint - including the movements possible.

Answer 21

Can move side to side, back and forth to facilitate sliding movements.

Question 22

Give examples of plantar joints.

Answer 22

Intercarpals and intertarsals

Question 23

Describe a hinge joint - including the movements possible.

Answer 23

The convex surface of one bone fits into concave of other to facilitate flexion and extension (single plane).

Question 24

Give examples of hinge joints.

Answer 24

Elbow and knee

Question 25

Describe a pivot joint - including the movements possible.

Answer 25

Round/pointed surface of one bone fits into ring formed by another (in addition to presence of ligament) and the movement facilitated is rotational.

Question 26

Give examples of pivot joints.

Answer 26

Atlas rotating on the axis (in the neck, C1 and C2) OR the radius and the annular ligament of the ulna (radius moves over ulna in supination and pronation movements)

Question 27

Describe a condylar (ellipsoidal) joint - including the movements possible.

Answer 27

Oval shaped condyle of one bone fits into elliptical cavity of the other bone and all movements are possible at this joint

Question 28

Give examples of condylar joints

Answer 28

Joint between carpals and radius (articulation between the scaphoid and the radius and the lunate and the radius)

Question 29

Describe a saddle joint - including the movements possible

Answer 29

One bone is 'saddle-shaped' and other is 'rider' all movements possible at these joints

Question 30

Give an examples of a saddle joint

Answer 30

Carpometacarpal joint of thumb (CMC)

Question 31

Describe a ball-and-socket joint - including the movements possible

Answer 31

Ball-shaped surface of one bone fits into cup-like depression of other, all movements possible at these joints

Question 32

Give examples of ball-and-socket joints

Answer 32

Hip and shoulder joints

Question 33

Rank the 6 synovial joint types from the least to most movable

Answer 33

plantar, hinge, pivot, condylar, saddle, ball-and-socket