Radioulnar joints Flashcards
What are the two radioulnar joints?
Proximal radioulnar joint
Distal radioulnar joint
Where is the proximal radioulnar joint located?
Distal to elbow joint
What is the joint capsule of the proximal radioulnar joint?
The same as the joint capsule of the elbow joint
What are the articulating surfaces of the proximal radioulnar joint?
Head of radius
Radial notch of ulna
What is the ligament of the proximal radioulnar joint?
The annular ligament
Where does the annular ligament attach?
Anterior and posterior ulna
What does the annular ligament do?
Holds the radial head in place
What is the annular ligament lined with? Why?
Synovial membrane
To reduce friction between the head of the radius and the annular ligament
so the head of the radius can spin in the annular ligament to produce movement
How is movement produced at the proximal radioulnar joint?
By head of radius rotating in annular ligament
Where is the distal radioulnar joint located?
Proximally to wrist joint
What are the articulating surfaces of the distal radioulnar joint?
Head of ulna
Ulnar notch of radius
What are the ligaments of the distal radioulnar joint?
Anterior ligament - strengthens joint anteriorly
Posterior ligament - strengthens joint posteriorly
Articular disk
What is the articular disk?
Fibrocartilaginous ligament
What does the articular disk attach to?
Radius and ulna
What are the functions of the articular disk?
Hold radius and ulna together
Seperate distal radioulnar joint from wrist joint
How is movement produced at the distal radioulnar joint?
Ulnar notch of radius
slides over head of ulna
What type of joint are the radioulnar joints?
Synovial joint
Pivot type
What are the movements of the radioulnar joints?
Pronation
Supination
Which muscles produce pronation at the radioulnar joints?
Pronator teres
Pronator quadratus
Which muscles produce supination at the radioulnar joints?
Biceps brachii
Supinator
What is the interosseus membrane?
Sheet of connective tissue between radius and ulna
Where does the interosseus membrane attach?
Lateral border of ulna
Medial border of radius
between proximal and distal radioulnar joints
How does vasculature pass through the interosseus membrane?
Interosseus membrane contains small holes for forearm vasculature to pass through
What are the functions of the interosseus membrane?
Hold radius and ulna together for stability
Site of attachment for muscles in forearm
Transfers force from radius to ulna
