MSK Upper Limb Flashcards
What is the axilla a passageway for?
Vessels
Nerves
Anterior border of the axilla
Pectoralis major
Pectoralis minor
Posterior border of the axilla
Teres major
Scapularis
Latissmus dorsi
Medial wall of axilla
Thoracic wall
Serratus anterior
Lateral wall of axilla
Intertubercular sulcus of the humerus
What is the axillary artery a continuation of?
Subclavian artery
When does the axillary artery begin?
Lateral border of the 1st rib
When does the brachial artery?
Beyond the margin of the teres major
Nerve roots of the brachial plexus
C5-T1
What does the brachial plexus innervate?
The upper limb
Order of the brachial plexus
Roots Trunks Divisions Cords Branches
What are the trunks of the brachial plexus?
Superior
Middle
Inferior
What are the divisions of the brachial plexus?
Anterior
Posterior
What are the cords of the brachial plexus?
Lateral
Posterior
Medial
Branches of the brachial plexus
Musculocutaneous Axillary Medial Radial Ulnar
What does injury to the superior trunk cause?
Erb’s palsy
What does injury to the lower trunk cause?
Klumpke’s palsy
The cords of the brachial plexus are named in relation to what?
The axillary artery in the axilla
What are in close relation to the brachial plexus?
Anterior and posterior scalenes
Subclavian artery
What end of the dorsal venous arch does the cephalic vein make up?
Lateral end
What end of the dorsal venous arch does the basilic vein make up?
Medial end
What are superficial veins of the upper limb used for?
IV injections for transfusion
Blood testing
What is the median cubital vein?
Large communicating vein which shunts blood from the basilic vein to the cephalic vein
What is a dermatome?
An area of skin supplied by one spinal segment
What lymph nodes are the upper limbs drained by?
Axillary nodes
5 groups of axillary nodes
Anterior/pectoral group Posterior/subscapular group Apical group Central group Lateral/humeral group (Axillary)
Another name for the shoulder girdle
Pectoral girdle
Function of the shoulder girdle
A set of bones that connect the upper limb to the axial skeleton on each side
What type of cartilage is the glenoid labrum?
Fibroelastic cartilage
Where is the clavicle commonly fractured?
Middle 1/3rd
What type of joint is the acromioclavicular joint?
Synovial plane joint
What type of joint is the sternoclavicular joint?
Synovial saddle joint
What type of joint does the sternoclavicular joint ACT as?
Synovial ball and socket joint
What ratio do the scapula and humerus move in?
1:2 ratio
What is the scapulo-humeral rhythm?
Beyond approx. 30 degrees, for every 3 degrees of abduction, 2 degrees occur at the shoulder joint and 1 degree at the scapulothoracic joint
What is the scapulo-thoracic joint?
The movement of the scapula on the thoracic wall
What elevates the scapula?
Levator scapulae
Serratus anterior
Rhomboids
Superior fibres of the trapezius
What depresses the scapula?
Pectoralis major
Pectoralis minor
Lattissimus dorsi
Inferior fibres of the trapezius
What retracts the scapula?
Middle fibres of the trapezius
Rhomboids
Lattisimus dorsi
What causes lateral (upward) rotation of the glenoid cavity?
Trapezius (upper and lower fibres)
Serratus anterior
What causes medial (downward) rotation of the glenoid cavity?
Gravity
Levator scapulae
Rhomboids
Pectoralis major
Another name for the shoulder joint
Gleno-humeral joint
What type of joint is the shoulder joint?
Synovial ball and socket joint
What is the ball and what is the socket of the shoulder joint?
Ball - head of humerus
Socket - Glenoid cavity
Function of the glenoid labrum
Deepens the glenoid cavity and effectively increases the surface of the shoulder joint
Ligaments of the shoulder joint
Transverse humeral ligament Glenohumeral ligament Coracoacromial ligament Coracoclavicular ligament Coracohumeral ligament
What does the coracoacromial ligament strengthen?
The superior aspect
What does the coracohumeral ligament strengthen?
Superior aspect
Function of the coracoclavicular ligament?
Maintains alignment of the clavicle
What is the weak area of the shoulder and why?
The glenohumeral ligament
Not supported by any muscles
What does the glenohumeral ligament strengthen?
The anterior aspect
What makes up the coracoacromial arch?
Acromion
Coracoid process
Coracoacromial ligament
Function of the coracoacromial arch
To prevent upward displacement of the humeral head
Two bursae of the shoulder
Subacromial (subdeltoid) bursae
Subscapular bursae
What shoulder bursae communicates with the shoulder cavity?
Subscapular bursae
What shoulder bursae is injured in a rotator cuff tear?
Subacromial bursae
What is the subacromial/deltoid bursae related to?
Supraspinatus tendon
What are the rotator cuff muscles?
Subscapularis
Supraspinatus
Infraspinatus
Teres minor
Action of the anterior fibres of the deltoid
Flexion of shoulder
Internal rotation of shoulder
Action of the middle fibres of the deltoid
Abduction of the shoulder
Action of the posterior fibres of the deltoid
Extension at shoulder joint
External rotation of shoulder joint
Innervation of the deltoid
Axillary nerve
How can the axillary nerve be damaged?
Fracture of the surgical neck of the humerus
How can you test for axillary nerve function?
Deltoid
Test for sensation on lateral side of proximal forearm
Actions of pectoralis major on the shoulder
Adduction
Internal rotation
Flexion
Borders of the deltopectoral triangle
Deltoid
Clavicle
Pec major
What is found in the deltopectoral triangle and what is it used for?
Cephalic vein
Used for central lines
Actions of serratus anterior
Protraction of scapulae
Stabilises scapulae during limb movements and keeps it pulled against the thoracic cage
What innervates the serratus anterior?
Long thoracic nerve
Damage to the long thoracic nerve causes what?
Winging of scapulae
Pathology of winging of scapulae
Medial border of scapulae moves laterally and posteriorly away from thoracic wall
What procedure can result in winging of the scapulae?
Radical mastectomies
What do superior fibres of the trapezius do?
Elevate scapulae
What do middle fibres of the trapezius do?
Retract scapulae
What do inferior fibres of the trapezius do?
Depress the scapulae
Innervation of trapezius
Accessory nerve
Roots of accessory nerve
CN XI
Action of teres major on shoulder
Adduction
Extension
Medial rotation
Action of lattisimus dorsi on the shoulder
Extension
Adduction
Medial rotation
What flexes the shoulder?
Anterior fibres of deltoid
Serratus anterior
Pectoralis major
What extends the shoulder?
Posterior fibres of deltoid
Lattisimus dorsi
Teres major
What adducts the shoulder?
Lower pec major
Latissimus dorsi
Teres major
Teres minor
What abducts the shoulder?
Middle fibres of the deltoid
Supraspinatus
What laterally/externally rotates the shoulder?
Teres minor
Infraspinatus
Posterior fibres of the deltoid
Lower trapezius
What medially/internally rotates the shoulder?
Anterior fibres of deltoid
Teres major
Lattisimus dorsi
Pectoralis major
What does the long head of the biceps brachii arise from?
Supraglenoid tubercle
What does the short head of the biceps brachii arise from?
The coracoid process
Where do the two heads of the biceps brachii tendon insert?
The tuberosity of the radius
Actions of the biceps brachii
Flexes shoulder
Flexes elbow
Supinator of radio-ulnar joint
Innervation of biceps brachii
Musculocutaneous nerve
Musculocutaneous nerve roots
C5-C7
Axillary nerve roots
C5 + C6
What cord is the musculocutaneous nerve from?
Lateral cord
What cord is the axillary nerve from?
Posterior cord
Muscles of the anterior arm
Biceps brachii
Brachialis
Coracobrachialis
Root values of the median nerve
C5-T1
Median nerve cord
Lateral and medial cords
Root values of the radial nerve
C5-T1
Radial nerve cord
Posterior cord
Ulnar nerve roots
C8-T1
Ulnar nerve cord
Medial cord
Attachments of the coracobrachialis
From the coracoid process
Inserted into the medial margin of the humerus at about its middle
Actions of coracobrachialis
Flexion of shoulder
Adduction of shoulder
Innervation of coracobrachialis
Musculocutaneous
Innervation of brachialis
Musculocutaneous
Attachments of brachialis
Arises from front of the distal 1/2 of the shaft of the humerus
Actions of brachialis
Flexion of elbow
What does the musculocutaneous nerve perforate?
Coracobrachialis
What does the musculocutaneous nerve descend between?
Brachialis and biceps brachii
What does the musculocutaneous nerve continue as?
Lateral cutaneous nerve of the forearm
What does the musculocutaneous nerve provide sensation to?
Lateral side of forearm
4 main nerves of the arm
Musculocutaneous
Radial
Ulnar
Median
What is the brachial artery a direct continuation of?
The axillary artery
When does the brachial artery begin?
Lower border of teres major
When does the brachial artery end?
In the cubital fossa close to the neck of the radius
What does the brachial artery divide into?
Radial and ulnar arteries
What is a deep artery which is a branch of the brachial artery?
Profunda brachii artery
On specimens, what does the median nerve look like?
Very thick
Where does the median nerve arise?
The axilla
Where does the median nerve descend?
along lateral side of axillary artery and upper part of brachial artery
Enters cubital fossa
Where does the ulnar nerve descend?
Along the medial side of the brachial artery (Artery lateral to nerve)
Enters posterior compartment of arm due to medial intermuscular septum and runs along the medial head of the triceps
How can the radial nerve be injured?
Injury to the radial groove of the humerus
How can the axillary nerve be injured?
By damage to the surgical neck of the humerus
How can the ulnar nerve be injured?
Damage to the medial epicondyle
Contents of the cubital fossa
Brachial artery Median nerve Radial nerve Biceps brachii Pronator teres Supinator Biceps brachii Brachioradialis Cubital vein
What can the cubital vein be used for?
IV injections
Base of cubital fossa
Imaginary line between the two epicondyles
Median border of border of cubital fossa
Lateral border of pronator teres
Lateral border of cubital fossa
Medial border of brachioradialis
Innervation of the triceps brachii
Radial nerve
Heads of the triceps brachii
Long
Medial
Lateral
Where does the long head of the triceps brachii insert?
Infraglenoid tubercle
Where does the triceps tendon insert?
Olecranon process of ulna
Action of triceps brachii
Extension at elbow
Innervation of anconeus
Radial nerve
Action of anconeus
Extension of elbow
What accompanies the radial nerve in the radial groove?
Profunda brachii artery
Injury to the radial nerve causes what?
Wrist drop
Pathway of the radial nerve
Enters arm anterior to triceps
Runs with the profunda femoris artery
Curves around the midshaft region of the humerus in the radial groove
What type of joint is the elbow joint?
Synovial hinge
What muscles flex the elbow?
Biceps brachii
Brachialis
Brachioradialis
What muscles extend the elbow?
Triceps brachii
Anconeus
What is the function of the annular ligament?
Holds the head of the radius
What are the three ligaments on either side of the elbow?
Ulnar Collateral ligament
Radial collateral ligament
Annular ligament
What type of joints are the proximal and distal radio-ulnar joints?
Synovial pivot
How would one dislocate their radius from proximal radio-ulnar joint?
Pulled elbow or
Subluxation of radial head
What muscles supinate the radio-ulnar joints?
Biceps brachii
Supinator
What is the main supinator of the radio-ulnar joint?
Biceps brachii
What are the assisting muscles that cause supination of the radio-ulnar joint?
Extensor pollicus longus
Extensor carpi radialis longus
What muscles pronate the radio-ulnar joints?
Pronator teres Pronator quadratus Flexor carpi radialis Palmaris longus Brachioradialis
Innervation of the pronator teres
Median nerve
Innervation of flexor carpi radialis
Median nerve
Innervation of flexor carpi ulnaris
Ulnar nerve
Innervation of palmaris longus
Median nerve
Action of the pronator teres
Pronation
Actions of flexor carpi ulnaris
Flexion of wrist
Adduction of wrist
Actions of flexor carpi radialis
Flexion of wrist
Abduction of wrist
Action of the palmaris longus
Flexion of wrist
Which compartment does the Brachioradialis belong to?
Extensor compartment
Innervation of Brachioradialis
Radial nerve
Action of Brachioradialis
Flexion at elbow
What is the flexor digitorum superficialis superficial to?
Flexor digitorum profundus
Where does the FDS attach to?
middle/second phalanges of the 4 fingers
Actions of the Flexor digitorum superficialis
Flexion of wrist
Flexion at metacarpalphalangeal joints
Flexion at interphalangeal joints
What are the deep muscles of the forearm in contact with?
Bones and interosseous membranes
What are the deep muscles of the forearm?
Flexor digitorum profundus
Flexor pollicus longus
Pronator quadratus
Actions of flexor digitorum profundus
Flexes phalanges
Flexes wrist
Innervation of the flexor digitorum profundus
Medial (4th + 5th digits) = ulnar nerve
Lateral (2nd + 3rd digits) = median nerve
Innervation of the flexor pollicus longus
Median nerve
Action of the flexor pollicus longus
Flexion of thumb
Action of the pronator quadratus
Pronation
Innervation of pronator quadratus
Median nerve
Attachments of the pronator quadratus
Origin at ulna
Passes across to be inserted into radius
Where does the median nerve lie in relation to the brachial artery?
Superomedial to the artery
Where does the ulnar nerve enter the forearm?
By passing between the heads of the flexor carpi ulnaris muscle
Where does the ulnar nerve lie in relation to the ulnar artery?
Nerve lies medial to the artery
Where does the brachial artery divide?
At the neck of the radius
Where is the radial pulse felt?
Medial to the tendon of the flexor carpi radialis muscle
Bones forming the borders of the carpal tunnel
Scaphoid and trapezium on the lateral side
Pisiform and hamate on the medial side
What is the flexor retinaculum?
A strong fibrous band which converts the concavity of the palmar surface (carpal bones) into a channel - the carpal tunnel
Contents of the carpal tunnel
Median nerve
4 tendons of the FDS
4 tendons of the FDP
1 tendon of the FPL
What is carpal tunnel syndrome caused by?
Any lesion that significantly reduces the size of the carpal tunnel
Most sensitive structure of the carpal tunnel affected in carpal tunnel syndrome
Median nerve
What is the palmar fascia (aponeurosis) a continuation of?
Palmaris longus muscle
What make up the thenar eminence?
Abductor pollicus brevis
Flexor pollicus brevis
Oppenens pollicus
What innervates the thenar muscles?
Median nerve
What makes up the hypothenar eminence?
Abductor digiti minimi
Flexor digiti minimi
Oppenens digiti minimi
What innervates the hypothenar eminence?
Ulnar nerve
Action of abductor digiti minimi
Abduction of pinkie
Action of flexor digiti minimi
Flexes MCP of pinkie
Action of opponens digiti minimi
Flexes pinkie towards palm, producing oppositio
Two heads of the adductor policus
Transverse
Oblique
Innervation of adductor policus
Ulnar nerve
Where does each lumbrical originate from?
The tendon of the flexor digitorum profundus
Actions of lumbricals
Flex fingers at the MCP joint and SIMILTANEOUSLY
Extend the interphalangeal joints of digitis 2-5
Innervation of lumbricals
medial 2 lumbricals = ulnar nerve
Lateral 2 lumbricals = median nerve
What are the interossei bones present between?
The metacarpal bones
How many interossei do we have?
4 dorsal
3 palmar
Innervation of interossei
Ulnar nerve
Action of dorsal interossei
DAB
Abduction
Action of palmar interossei
PAD
Adduction
What artery is the main contributor to the superficial palmar arch?
Ulnar artery
What artery is the main contributor to the deep palmar arch?
Radial artery
What does the radial nerve supply on the hand?
Skin on the dorsal aspect of the hand
How does the median nerve enter the hand?
Through the carpal tunnel
Another name for the wrist joint
Radiocarpal joint
What type of joint is the wrist joint?
Synovial condyloid
Articular parts of the wrist joint
Proximal = radius Distal = proximal row of carpal bones
3 bones of the hand
Carpals
Metacarpals
Phalanges
Which carpal bone is most commonly fractured and what does this mean it is at risk of?
Scaphoid
Avascular necrosis
Blood supply to the scaphoid
Distal to proximal
What type of joint is the 1st CMC joint?
Synovial saddle
What type of joint is the 2nd-5th CMC joints?
Synovial condyloid
What type of joints are the MCP joints?
Synovial condyloid
What type of joints are the interphalangeal joints?
Synovial hinge
What innervates the posterior forearm muscles?
Radial nerve
Action of extensor carpi radialis longus and brevis
Extension of wrist
Abduction of wrist
Action of extensor carpi ulnaris
Extension of wrist
Adduction of wrist
Action of extensor digitorum
Extends medial 4 digits at MCP joint
Action of Brachioradialis
Flexion at elbow
Innervation of brachioradialis
Radial nerve
Innervation of supinator
Radial nerve
Action of extensor digiti minmi
Extends 5th finger at MCP joint
What does the supinator cover?
Shaft of radius completely EXCEPT on medial side
Action of supinator
Supination of radio-ulnar joints
What does the radial nerve divide into and where?
Superficial and deep branches
In the cubital fossa
What is the deep branch of the radial nerve also called?
Posterior intraosseous nerve
Features of the superficial branch of the radial nerve
Sensory
Is distributed on skin on dorsum of hand
What occurs on the dorsum of the hand from the extensor muscle tendons?
Synovial sheaths
What results in a “dinner fork deformity”?
Colles fracture of distal radius
What is the anatomical snuffbox?
A shallow depression on the lateral aspect of the wrist when the thumb is extended fully
What binds the anatomical snuffbox laterally?
Abductor pollicus longus
Extensor pollicus brevis
What binds the anatomical snuffbox laterally?
Extensor pollicus longus
What two carpal bones are in the anatomical snuffbox?
Scaphoid
Trapezium
What lies on the floor of the anatomical snuffbox?
Radial artery
What are the extensor compartment thumb muscles innervated by?
Radial nerve
When the 4 extensor digitorum tendons flatten, what do they form and what are these?
Form extensor expansions
These are triangular tendinous aponeurosis that wraps around the dorsum and sides of the head of the metacarpal and base of the proximal phalanx
What muscles attach to the extensor expansion muscle?
Lumbricals
Extensor indices
Dorsal interossei
Palmar interossei
When may compression of the axillary artery be necessary?
When profuse bleeding occurs due to severe injury to the upper limb
What is common in the infection of the upper limb?
Enlargement of axillary lymph nodes
What does erbs palsy result in?
Waiter’s tip position
What is the presentation of waiters tip position?
Medially rotated with wrist flexed
What causes upper brachial plexus injury and give some examples?
Undue hyperextension of head from shoulder
Fall on the shoulder
Birth injury
During anaesthesia
What causes klumpkes palsy?
Undue abduction of arm
What muscles are affected in klumpkes palsy?
Intrinsic muscles of hand
Ulnar flexors of wrists and fingers
Branches of the lateral cord of brachial plexus
Lateral pectoral
Lateral root of medial nerve
Musculocutaneous
Branches of the medial cord of brachial plexus
Medial pectoral Ulnar Medial cutaneous nerve of arm Medial cutaneous nerve of forearm Median
Branches of posterior cord of brachial plexus
Thoracodorsal nerve
Axillary
Radial
Subscapular nerve
What makes up the coracoclavicular ligament?
Trapezoid ligament
Conoid ligament
What is the conoid tubercle an attachment for?
Conoid ligament
What are the attachments of the conoid ligament?
Binds the clavicle to the coracoid process of the scapula
Function of the shoulder joint ligaments
Strengthen and ease the movements at the shoulder joint
What are shoulder ligaments made from?
Thickening of joint capsule
What nodes would drain the infection of the pinkie?
Superficial inguinal nodes
What nodes would drain a boil in the scapular region?
Axillary
What nodes would drain the medial part of the breast close to the sternum?
Internal thoracic nodes
What nodes would drain the lateral part of the breast close to the axilla?
Axillary
Lymphatic drainage of above the umbilicus?
Axillary
Lymphatic drainage of below the umbilicus
Superficial inguinal
