The Elbow and Forearm Flashcards
What is the purpose of the interroseous membrane?
Stope ulna and radius separating under force and transmits force
What is the interroseous membrane made of?
Fibrous tissue which pass downward from the radius to the ulna
Classify the elbow joint
Synovial, hinge and pivot joint
What actions does the humeroradial joint and numeroulnar joint perform?
1) probation and supination 2) flexion and extension
Where is the olecranon bursa located? What is its purpose?
Posterior aspect of the elbow. Protective padding of the elbow
What forms the humeroulnar joint?
Torch leat of humerus and trochlear notch of the ulna
What binds the radius and ulna together?
Interroseous membrane
What muscle attachment structures are on the distal humerus?
medial and lateral epicondyles
What structure of the distal humerus articulates with the ulna and radius?
condyle
What structure articulates with the radial fossa of the radius (anterior)
capitulum
What structure of the distal humerus articulates with the coronoid fossa of the ulna?
trochlea
In relation to the forearm bones, what head is proximal?
radius
What structure on both the radius and ulna is for muscle attachment?
radial and ulna tuberosities
What structure limit the extension and accommodates the olecranon?
olecranon fossa
What bone is the olecranon on?
ulna
What is the function of the radial styloid?
stabilize wrist joint
What movements does the radial head allow?
pronation and supination
Muscles inserting onto what forearm bone cause pronation and supination?
radius
What bone remains straight during pronation and supination?
ulna
Where is the ulna styolid located?
distal head of ulna near the wrist
When the forearm is extended, where does the olecranon of the ulna go?
olecranon fossa
What structure of the ulna accommodates the radial head during pronation and supination?
radial notch
Muscles inserting into what forearm bone cause flexion and extension of the elbow
ulna
What joins the ulna and radius together?
Interosseous membrane
What makes the interosseous membrane strong?
It is a fibrous membrane, direction of fibers in downwards for force transmission and allows rotation to occur
Where do the interosseous membrane fibers pass downward from?
radius to ulna
classify the elbow joint
synovial hinge and pivot joint
What structural joint is the 1) Humeroulnar joint 2) Humeroradial joint and what movements do each produce?
1) Hinge - flexion and extension 2) pivot - pronation and supination
Where is the olecranon bursa located? What is its purpose?
Posterior aspect of elbow serving to protect the elbow from impact
What bony landmarks doe the humeroulnar joint occur at?
Trochlear of humerus and trochlear notch of the ulna
Outline ligaments of the elbow.
radial collateral ligament ulnar collateral ligament annular ligament
Compare the ulnar to the radial collateral ligament
Ulnar collateral ligament is broader and stronger than the radial collateral ligament due to more dynamic activity
Describe the annular ligament and what it assists in
Funnel shaped ligament that is wider superiorly than inferiorly to accommodate the radial head. Allows pronation and supination
What are the muscles acting on the elbow joint?
-biceps brachii -brachialis -brachioradialis -triceps brachii -anconeus -pronater teres
Describe the attachments of biceps brachii
Origin: coracoid process of scapula Insertion: radial tuberosity
What actions does the biceps allow?
flexion (more efficient when arm is pronated) and a bit of supination
What does the biceps stabilize?
shoulder joint
What muscle is deep to the biceps?
brachialis
What are the attachments of brachialis?
humerus to ulna
What actions does brachialis allow?
flexion
What are the attachments of the brachioradialis
arises half way up humerus below deltoid tuberosity) and inserts on distal radius
What two muscles are posterior of the elbow joint? Deduce what actions they cause
- Triceps brachii and anconeus - cause extension - anconeus is a minor extensor
What are the attachments of the triceps?
arises from scapula and humerus. Long tendon inserts on olecranon process of ulna
Why can’t the triceps pronate or supinate?
It does not insert on the radius
What muscle does the anconeus oppose?
brachialis
What are the attachments of anconeus?
epicondyle of humerus to ulna
What does the anconeus assist with?
extension and locking the elbow.
Describe the superior humeroradial joint
small articulation below and part of the ulna which allows pronation and supination.
What are the joint surfaces of the superior humeroradial joint?
- capitulum of humerus - head of radius
What are the joint surfaces of the proximal radioulnar articulation?
- head of radius - radial notch of ulna - annular ligament
At the distal radioulnar joint, where is the articular disc located? What is its function?
- between radius and ulna - increases congruency between joint surfaces as there is not a perfect fit
Which joint does most of pronation and supination take place?
proximal radioulnar joint - not distal as the bones must stay relative to one another
Classify the inferior radioulnar joint
synovial, uniaxial pivot joint
What are the movements of the inferior radioulnar joint?
pronation, midprone/neutral and supination
Which movement (either pronation or supination) are the radius and ulna parallel with one another?
supination
What is a common property of pronator and supinator muscles?
fibers run obliquely
Where does pronator teres originate and insert?
originates on ulna and humerus, inserts on radius
Where does aupinator originate and insert?
originates on ulna and humerus, inserts on radius
What are the attachments of pronator quadratus?
originates on ulna and inserts on radius
What is the function of pronator quadratus?
assists pronator teres in pronation
List muscles of pronation and supination
pronator teres pronator quadratus supinator
Are the muscles of pronation and supination superficial or deep?
deep
Which muscle of pronation/supination wraps around the radius?
supinator
What are the nerves that supply the upper limb?
- musculocutaneous - median nerve -ulnar nerve - radial nerve
What is the innervation of biceps?
musculocutaneous nerve
What is the innervation of brachialis?
musculocutaneous nerve
What is the innervation of brachioradialis?
radial nerve
What is the innervation of triceps brachii?
radial nerve
What is the innervation of anconeus?
radial nerve
What is the innervation of pronator teres?
median nerve
What is the innervation of pronator quadratus?
median nerve
What is the innervation of supinator?
radial nerve
Identify the following muscle
Biceps Brachii
Label the following diagram
Identify the following muscle
Brachialis
Identify the following muscle
brachioradialis
Identify the following muscle
Triceps brachii
Identify the following muscle
anconeus
Identify the following muscles
Label the nerves of the upper limb
