Anatomy Flashcards
What is the action of pectoralis major on the gleno-humoral joint?
Adduction, flexion and medial rotation.
What muscles contribute to form the anterior border of the axilla?
Pectoralis major and pectoralis minor
What are the terminal branches of the posterior cord of the brachial plexus?
Radial and axillary nerve
From which part of the brachial plexus does the nerves supply to latissimus dorsi arise?
Thoracodorsal nerve arises from the posterior cord
Which muscle does the musculocutaneous nerve normally pierce?
Coracobrachialis
Which nerves normally form the roots of the brachial plexus?
Anterior (ventral) rami of spinal nerves in region of C5-T1
What is the scapular attachment of the pectoralis minor?
The coracoid process
Why would the action of the serratus anterior rarely be affected by a lesion of the brachial plexus?
It is supplied by the long thoracic nerve which arises very proximal so is unlikely to be affected by lesions of the brachial plexus.
Which 3 joints make up the elbow?
- humeroulnar joint
- humeroradial joint
- proximal radioulnar joint
What movements are facilitated through the elbow joints?
- flexion
- extension
- pronation
- supination
How is the elbow joint stabilised?
From the bony articulations of the trochlea (humerus) and olecranon (ulna).
Where does the humerus articulate with the radius and ulna?
- radius articulates with capitulum
- ulna articulates with trochlea
What is an epicondyle?
A prominence on the distal part of a long bone which serves as an attachment for muscles and ligaments.
What is an aponeurosis?
A broad flat sheet of dense, fibrous, collagenous connective tissue that covers, invests and forms the terminations and attachments of various muscles.
Describe the humeroulnar joint.
- main joint of the elbow
- medial
- articulation between trochlea of humerus and trochlear notch of ulna
- reinforced by the ulnar collateral ligament
- allows for flexion and extension
- not involved in pronation/supination
Describe the humeroradial joint.
- lateral
- articulation between the capitulum of humerus and head of radius
- reinforced by the radial collateral ligament
- allows for pronation and supination
Describe the superior radioulnar joint.
- associated with elbow
- pivot synovial joint
- articulation between head of radius and osseofibrous ring (radial notch of the ulna and anular ligament)
- radial head is held in position by the anular ligament of the radius
- allows for pronation and supination of the forearm
Describe the inferior radioulnar joint.
- pivot synovial joint
- articulation between the head of the ulna and the ulnar notch of the radius
- held together by an articular disc and interosseous membrane
Describe the ulna.
- medial and longer than the radius
- at proximal end contains the trochlear notch, coranoid process anteriorly, olecranon process posteriorly
- at distal end contains head of ulna and styloid process
Describe the radius.
- lateral
- at proximal end contains head of radius and radial tuberosity medially (biceps attach here)
- at distal end contains styloid process laterally and ulnar notch medially
- distal end articulates with ulna and proximal carpal bones
List the bursae around the elbow joint.
- intratendinous olecranon bursa
- subtendinous olecranon bursa
- subcutaneous olecranon bursa
- bicipitoradial (biceps) bursa (separates biceps tendon from anterior part of radial tuberosity)
Which muscles act as flexors of the arm?
- biceps brachii
- Coracobrachialis
- brachialis
Which muscles act as extensors of the arm?
- triceps
- aconeus
Describe pronation of the forearm.
- palm turned posteriorly
- proximal radius lateral to ulna
- distal radius medial to ulna
Describe supination of the forearm.
- palm turned anteriorly
- pronation movement reversed
- radius lateral to and parallel with ulna
List the ligaments associated with the elbow.
- radial annular ligament
- ulnar collateral ligament
- radial collateral ligament
What muscles are involved in pronation and supination?
Supination - biceps brachii
Pronation - pronator teres, pronator quadratus and possibly aconeus
Describe the cubital fossa.
- important transition between arm and forearm
- concavity under crease, anterior to elbow joint
- triangular depression bound by brachioradialis laterally and pronator teres medially
- median nerve runs through
- radial nerve found laterally if brachioradialis is retracted
List the muscles of the anterior compartment of the forearm.
Superficial: pronator teres, flexor carpi radialis, palmaris longus, flexor carpi ulnaris
Intermediate: flexor digitorum superficialis
Deep: flexor digitorum profundus, flexor pollicis longus, pronator quadratus
List the muscles of the posterior compartment of the forearm.
Superficial: brachioradialis, extensor carpi radialis longus, extensor carpi radialis breves, extensor digiti minimi, extensor carpi ulnaris
Deep: supinator, extensor indicis, abductor pollicis longus, extensor pollicis longus, extensor pollicis brevis
