Radioulnar Joint

Question 1

What are the radioulnar joints?

Answer 1

Two locations in which the ulna and radius articulate in the forearm

Question 2

Where is the proximal radioulnar joint?

Answer 2

Immediately distal to the elbow joint

Question 3

What is the proximal radioulnar joint the articulation of?

Answer 3

The head of the radius, and the radial notch of the ulna

Question 4

Where is the distal radioulnar joint?

Answer 4

Just proximally to the wrist joint

Question 5

What is the distal radioulnar joint the articulation of?

Answer 5

Between the radial notch of the radius and ulnar head

Question 6

What are the radioulnar joint classified?

Answer 6

Pivot joints

Question 7

What are the radioulnar joints responsible for?

Answer 7

Pronation and supination of the forearm

Question 8

What is the proximal radioulnar joint enclosed within?

Answer 8

The same articular capsule as the elbow joint

Question 9

What is the proximal radioulnar joint formed from?

Answer 9

An articulation between the head of the radius and the radial notch of the ulna

Question 10

How is the radial head held in place?

Answer 10

By the annular radial ligament

Question 11

What does the annular radial ligament form?

Answer 11

A ‘collar’ around the joint

Question 12

What is the annular radial ligament lined with?

Answer 12

A synovial membrane

Question 13

What is the purpose of the synovial membrane of the annular radial ligament?

Answer 13

It reduces friction during movement

Question 14

How is movement at the proximal radioulnar joint produced?

Answer 14

By the head of the radius rotating within the annular ligament

Question 15

What movements are possible at the proximal radioulnar joint?

Answer 15

Pronation and supination

Question 16

What is pronation at the proximal radioulnar joint produced by?

Answer 16

The pronator quadratus and the pronator teres

Question 17

What is supination at the proximal radioulnar joint produced by?

Answer 17

The supinator and biceps brachii

Question 18

What is the distal radioulnar joint an articulation between?

Answer 18

The ulnar notch of the radius, and the ulnar head

Question 19

What strengthens the distal radioulnar joint?

Answer 19

Anterior and posterior ligaments

The articular disc

Question 20

What is the articular disc?

Answer 20

A fibrocartilaginous ligament

Question 21

What is the function of the articular disc?

Answer 21

Binds the radius and ulna together, and holds them together during movement at the joint
Separates the distal radioulnar joint from the wrist joint

Question 22

What does the distal radioulnar joint allow for?

Answer 22

Pronation and supination

Question 23

What happens to the ulnar notch of the radius in movements of the distal radioulnar joints?

Answer 23

It slides over the head of the ulnar

Question 24

What produces pronation at the distal radioulnar joints?

Answer 24

The pronator quadratus and pronator teres

Question 25

What produces supination at the distal radioulnar joint?

Answer 25

Supinator and biceps and brachii

Question 26

What is the interosseous membrane?

Answer 26

A sheet of connective tissue that joins the radius and ulna together between the radioulnar joints

Question 27

What does the interosseous membrane span?

Answer 27

The distance between the medial radial border and the lateral ulnar border

Question 28

What is present in the interosseous membrane?

Answer 28

Small holes

Question 29

Why are there small holes in the interosseous membrane?

Answer 29

As a conduit for the forearm vasculature

Question 30

What are the major functions of the interosseous membrane?

Answer 30

Holds radius and ulna together during pronation and supination of the forearm, providing additional stability  Acts as a site of attachment for muscles in the anterior and posterior compartments of the forearm  Transfers forces from the radius to the ulna

Question 31

How can the radius and ulna be thought of when dealing with injury?

Answer 31

As a ring

Question 32

What is the result of the radius and ulna being thought of as a ring?

Answer 32

A ring usually breaks in two places, meaning that a fracture to the radius usually causes a fracture or dislocation to the other bone