Upper Limb 2 Flashcards
What is muscle A?
Supraspinatus
What is muscle B?
Subscapularis
What is muscle D?
Infraspinatus
What is muscle C?
Teres minor
What is the proximal and distal attachment of the subscapularis?
Proximal - medial 2/3 costal aspect of scapula
Distal - lesser tubercle of humerus
What does the subscapularis do in movement of shoulder joint?
Medially rotates and adducts joint
What is the proximal and distal attachment of the supraspinatus muscle?
Proximal - supraspinous fossa of scapula
Distal - greater tuberosity of humerus
What movement of the shoulder does the supraspinatus muscle do?
Initiates and assists in abduction of shoulder joint
What is the proximal and distal attachments of the infraspinatus muscle?
Proximal - infraspinatous fossa of scapula
Distal - middle facet of greater tubercle of humerus
What is the movement of shoulder that infraspinatus does?
Laterally rotates shoulder joint
What is the proximal and distal attachment of the teres minor?
Proximal - middle part of lateral border of scapula
Distal - greater tuberosity of humerus
What is the movement of shoulder which teres minor does?
Laterally rotates shoulder joint
What is the main function of the rotator cuff muscles?
Keep shoulder and upper arm stable when moving and in use
What is the cause of rotator cuff injuries?
Repetitive overhead motions
Increased stress on ligaments and muscles weakens them - so more likely to tear
Where does the deltoid muscle arise?
Lateral spine of scapula passing across the acromion to lateral third of clavicle
What is the distal attachment of the deltoid?
Deltoid tuberosity of humerus
What is the function of the anterior fibres of the deltoid?
Flexes and medially rotates at the shoulder joint
What is the function of the middle fibres of the deltoid?
Abducts the arm of the shoulder joint
What in the function of the posterior fibres of the deltoid muscle?
Extends and laterally rotates shoulder joint
What is the nerve supply to the deltoid?
Axillary nerve - C5 and C6
What common injury causes axillary nerve to be trapped and damaged?
Fracture of humerus
What is the origin of the pectoralis major?
Medial third of clavicle, sternum, costal cartilage of first 6 ribs and rectus sheath
What is the distal attachment of the pectoralis major?
Lateral lip of the bicipital groove of humerus
What is the action of the pectoralis major?
Adduct the shoulder and medially rotate the humerus at the glenohumeral joint
What is the function of the pectoralis minor?
Stabilises the scapula during limb movements by keeping it pulled against the thoracic cage
Where does the serratus anterior arise and insert?
Arises from interdigitations from ribs and inserts into scapula
What is the role of the serratus anterior?
Protection of the scapula
What nerve is affected when a patient has winged scapula?
Long thoracic nerve (C5,6 and 7) which supplies the serratus anterior
What is the role of the superior fibres of the trapezius?
Elevates the scapula
What is the role of the middle fibres of the trapezius?
Retracts the scapula
What is the role of the inferior fibres of the trapezius?
Depresses the scapula
What is the innervation of the trapezius?
Spinal accessory nerve
What muscles are involved in flexion of the shoulder?
Pectoralis major, anterior fibres of deltoid and coracobrachialis
What muscles are involved in the extension of the shoulder?
Posterior fibres of deltoid, latissimus dorsi and teres major
What muscles are involved in adduction of the shoulder?
Pectoralis major, latissimus dorsi, teres major and coracobrachialis
What muscles are involved in the abduction of the shoulder from 0 to 90 degrees?
Supraspinatus and deltoid
What muscles are involved in the abduction of the shoulder from 90 to 180 degrees?
Trapezius and serratus anterior
What muscles are involved in the medial/ internal rotation of the shoulder?
Subscapularis, latissimus dorsi, pectoralis major and teres major
What muscles are involved in the lateral/ external rotation of the shoulder?
Infraspinatus, teres minor and deltoid
What is A?
Greater tubercle
What is B?
Lesser tubercle
What is C?
Capitulum
What is D?
Trochlea
What is E?
Medial epicondyle
What is F?
Coronoid fossa
What is G?
Deltoid tuberosity
What is H?
Anatomical neck
What is I?
Head of humerus
What is J?
Olecranon fossa
What are the 3 important muscles of the anterior compartment of the arm?
Brachialis
Coracobrachialis
Biceps brachii
What nerve supplies the muscles in the anterior compartment of the arm?
Musculocutaneous nerve
Describe the biceps brachii
Most superficial muscle of anterior compartment
Arises from scapula from 2 heads
Both heads unite at distal 1/3 of upper arm forming short tendon which inserts into radial tuberosity
Where does the biceps brachii attach?
Radial tuberosity
Also, attaches through bicipital aponeurosis to deep fascia of the forearm
Where does the short head of the biceps brachii originate from?
Coracoid process of scapula
Where does the long head of the biceps brachii originate from?
Supraglenoid tubercle of the scapula - tendon passes through shoulder joint and runs down groove of humerus
What is the action of the biceps brachii?
Flexes both shoulder and elbow joint
Also, supination at superior radio-ulnar joint
What is the origin and insertion of the coracobrachialis?
Origin - coracoid process
Insertion - medial aspect of the mid-shift of the humerus
What is the action of the coracobrachialis?
Flex and adduct the arm at shoulder joint
What is the origin and insertion of the brachialis muscle?
Origin - anterior surface of distal shaft of humerus
Insertion - coronoid process of the ulna
What is the main action of the brachialis muscle?
Flex at elbow joint
Describe the musculocutaneous nerve
Nerve arises as terminal branch of lateral cord of brachial plexus
Main nerve of anterior compartment of the arm
What is the course of the musculocutaneous nerve?
Enters the arm by perforating the coracobrachialis, descending between the biceps brachii and brachialis muscle
After crossing elbow it gives off terminal branch to supply skin as lateral cutaneous nerve of the forearm
What is the segmental root value of the musculocutaneous nerve?
C5 to C7
Does the musculocutaneous nerve supply any muscles in the forearm or hand?
No
Where does the brachial artery begin and end?
Lower border of teres major and ends in cubital fossa by dividing into radial and ulnar arteries
What is a main branch of brachial artery?
Profunda brachii - deep artery of the arm
Passes deep to triceps muscle along with radial nerve
What cords does the median nerve arise from?
Lateral and Medial cords of brachial plexus
In the middle part of arm, what is the course of the median nerve?
Crosses to medial aspect of brachial artery and enters cubital fossa
Describe the course of the ulnar nerve
Descends along the medial side of brachial artery and enters forearm (posterior) compartment through medial intermuscular septum
Runs along medial head of triceps and lie behind medial epicondyle of elbow
Describe the triceps
Occupies entire posterior compartment of arm
Arises by long head from scapula and 2 shorter heads from humerus
Insertion is olecranon of ulna
Which head of the triceps attaches onto infra-glenoid tubercle of scapula?
Long head
What is the main action of the triceps on elbow?
Chief extensor
What is the anconaeus muscle?
Small muscle which aids triceps action at elbow joint
What is the nerve supply to triceps and anconeus?
Radial nerve
Triceps - C6-8
Anconeus - C7, 8 and T1
What does the radial nerve supply?
Posterior compartment of arm and forearm
What is the course of the radial nerve?
Enters anterior to long head of triceps and runs with profunda brachii artery
Descends down mid-shaft region of humerus in radial groove then appears on distal arm between brachialis and brachioradialis
What segmental root is the radial nerve?
C5-T1
What is the characteristic sign of radial nerve injury?
Unable to extend wrist
Wrist drop
What fractures can cause potential nerve injuries?
Radial nerve - fracture of spinal groove
Ulnar nerve - fracture of medial epicondyle
Axillary nerve - fracture of surgical neck
What is the antecubital fossa?
Triangular depression on anterior aspect of elbow
Corresponds to popliteal fossa of the knee
Acts as conduit of neurovascular structures
What vein lie anterior to the roof of the antecubital fossa?
Median cubital vein
What level does brachial artery bifurcate into radial and ulnar arteries?
Apex of antecubital fossa
What type of joint is the elbow joint?
Synovial hinge
Which ligament hold the ulna in place?
Ulna collateral ligament
What ligament holds the head of the radius?
Annular ligament
What is students elbow?
Subcutaneous olecranon bursa can be damaged through repeated excessive pressure and friction
Olecranon bursitis
What is tennis elbow?
Repetitive overuse of muscles in forearm causes inflammation of tendons attached to lateral epicondyle of elbow - lateral epicondylitis
What is golfers elbow?
Repetitive overuse of muscles in forearm causes inflammation of the muscles attached to the medial epicondyle of the elbow - medial epicondylitis
What type of joint is the radio-ulnar joints?
Synovial pivot
What muscles are involved in supination of the radio-ulnar joint?
Supinator and biceps brachii
What muscles are involved in pronation of radio-ulnar joints?
Pronator quadratus and pronator teres
