Upper arm anatomy Flashcards
How many muscles are in the anterior compartment of the arm?
3
How many muscles are in the posterior compartment of the arm?
1
Which muscles are in the anterior compartment of the arm?
Biceps
Coracobrachialis
Brachialis
Which muscle is in the posterior compartment of the arm?
Triceps
What is the blood supply to the anterior compartment of the arm?
Branches of the brachial artery
What is the function of the biceps?
Forearm supination
Elbow and shoulder flexion
What is the innervation of the biceps?
MUsculocutaneous nerve.
Which spinal cord segment does the bicep tendon reflex test?
C6
What is the function of the coracobrachialis?
Flexion of the shoulder
Weak shoulder adduction
What is the innervation of the coracobrachialis?
Musculocutaneous nerve
The brachial forms the floor of what?
Cubital fossa
What is the function of the brachialis?
Elbow flexion
What is the innervation fo the brachialis?
Musculocutaneous nerve (contributions from radial nerve)
What is the main innervation for the anterior compartment of the upper arm?
Musculocutaneous
What injury can cause the ‘Popeye sign’?
Complete rupture of the long head of the biceps.
What is the arterial supply to the posterior compartment of the upper arm?
Profunda brachii artery
What is the function of the triceps?
Elbow extension.
What is the innervation of the triceps?
Radial nerve.
What spinal segment does the triceps reflex test?
C7
Where are the infraclavicular node groups found?
Between the pectoralis major and deltoid, immediately below the clavicle.
What regions do the infraclavicular lymph nodes drain?
Axilla and anterior thoracic wall
Where are the supratrochlear lymph nodes found?
Proximal to the medial epicondyle of the humerus.
What regions do the supratrochlear lymph nodes drain?
Fingers 3-5 and the medial forearm.
What type of joint is the elbow?
Hinge synovial joint
How many articulations does the elbow joint have?
2
At the elbow, the trochlear notch of the ulna articulates with….?
The trochlea of the humerus.
At the elbow, the head of the radius articulates with….?
The capitulum of the humerus.
What are the 2 articulations that form the elbow joint?
The trochlear notch of the ulna + trochlea of humerus
AND
The head of the radius and the capitulum of the humerus
What do the thickenings of the elbow joint capsule at the medial and lateral aspects of the elbow joint form?
The collateral ligaments.
What is the function of the collateral ligaments in the elbow?
They stabilise the flexing and extending motion of the arm.
Which collateral ligement blends with the annular ligament?
The lateral collateral ligament
Which movements does the annular ligament allow for?
Pronation and supination.
What is the third articulation of the elbow?
Proximal radioulnar joint between the radial head and radial notch.
**often considered a separate articulation.
Which muscles allow for elbow flexion?
Triceps
Anconeus
Which muscles allow for elbow extension?
Brachialis
Biceps
Brachioradialis
How are elbow dislocations named?
By position of the ulna and radius (not humerus)
Which area is affected by tennis elbow?
Lateral epicondylitis
Which area is affected by golfer’s elbow?
Medial epicondylitis
What movement do the proximal and distal radio ulnar joints allow for?
Rotational movement of the 2 bones (pronation and supination).
What forms the proximal radio ulnar articulation?
Head of radius and radial notch on ulna.
What holds the radial head in place at the proximal radio ulnar joint?
Annular radial ligament.
What muscles allow for pronation at the proximal radio ulnar joint?
Pronator quadrates and pronator teres.
Which muscles allow for supination at the proximal radio ulnar joint?
Supinator and biceps.
What forms the articulation of the distal radioulnar joint?
Ulnar head and ulnar notch of radius.
What holds the radius and ulna together at the distal radio ulnar joint?
Articular disc.
Which muscles allow for pronation at the distal radioulnar joint?
Pronator teres and pronator quadratus.
Which muscles allow for supination at the distal radio ulnar joint?
Supinator and biceps.
What holds the radius and ulna together during pronation and supination of the forearm?
Interosseous membrane.
What are the 2 common fractures affecting the forearm?
Monteggia and Galeazzi
What is a Monteggia fracture?
Fracture of proximal ulna AND dislocation of radial head proximally.
What is a Galeazzi fracture?
Fracture of distal radius and dislocation of ulnar head distally.
What is the function of the latissimus dorsi?
Adduct, extend and internally rotate humerus
