Upper Limb Anatomical Areas Flashcards
The axilla is an area that lies below the ________________ joint at the junction of the upper limb and ___________
Glenohumeral joint
Thorax
What general shape does the axilla have?
A pyramid shape - lateral wall, medial wall, anterior wall, posterior wall and apex
What is the apex of the axilla formed by? (3)
The lateral border of the first rib
The superior border of the scapula
The posterior border of the clavicle
What forms the lateral wall of the axilla?
The interturbercular groove of the humerus
What forms the medal wall of the axilla?
Serratus anterior and thoracic wall
What forms the anterior wall of the axilla?
Pectroalis major, pectoralis minor
What forms the posterior wall of the axilla?
Subscapularis, teres major and lattisimus dorsi
How does the size and shape of the axilla change with full abduction? What is the clinical significance of this?
Decreases in size when arm is fully abducted
The contents of the axilla are at most risk of injury when the arm is fully abducted
What are the contents of the axilla? (5)
Medial and posterior parts of the axillary artery Axillary vein Brachial plexus Biceps brachii and coracobrachialis Axillary lymph nodes
What are the three main routes by which structures leave the axilla?
Immediately inferiorly and laterally into the upper limb
Quadrangular space
Clavipectoral triangle
Where is the quadrangular space?
In the posterior wall of the axilla
What structures pass through the quadrangular space?
The axillary nerve
Posterior circumflex humeral artery
Where is the clavipectoral triangle?
In the anterior wall of the axilla
The clavipectoral triangle is bounded by… (3)
The pectoralis major, deltoid and clavicle
What structures enter and leave through the clavipectoral triangle?
Cephalic vein enters the axilla
Medial and lateral pectoral nerves leave the axilla
What is thoracic outlet syndrome?
Where the nerves and vessels entering the axilla become compressed between the bones making up the apex
What are common causes of thoracic outlet syndrome? (2)
Trauma (e.g. Fractured clavicle)
Respective actions
How does thoracic outlet syndrome often present?
Pain in the affected limb, tingling, muscle weakness, discolouration
What can be biopsied in cases of suspected breast cancer? Why?
Axillary lymph nodes
Majority of the lymph from the breast drains here
What is axillary clearance?
Removal of the axillary lymph nodes to prevent the spread of cancer
The cubital fossa is located as a depression on the ____________ surface of the ________ joint
Anterior
Elbow
What shape does the cubital fossa have?
Triangular
What is the lateral border of the cubital fossa?
The medial border of the brachioradialis muscle
What is the medial border of the cubital fossa?
The lateral border of the pronation teres muscle
What is the superior border of the cubital fossa?
The imaginary line between the epicondyles of the humerus
What is the floor of the cubital fossa formed by?
Proximally by the brachialis
Distally by the supinator muscle
What forms the roof of the cubital fossa?
Skin and fascia and reinforced by the bicipital aponeurosis
What vessel runs in the roof of the cubital fossa? What is the clinical significance of this?
Median cubital vein
It can be accessed for venepuncture
What are the contents of the cubital vessel? (4)
Radial nerve
Biceps tendon
Brachial artery
Median nerve
The median cubital vein connects which two veins?
Basilic
Cephalic
How can the brachial pulse be felt?
Palpating immediately medial to the biceps tendon
How does a supracondylar fracture usually occur?
Falling on a flexed elbow
A supracondylar fracture is a transverse fracture spanning between the two ______________
Epicondyles
What is volkmann’s ischaemic contracture? What causes it?
Uncontrolled flexion of the hand as flexor muscles become fibrotic and short
Damage to the brachial artery causing ischaemia
Which of the structures in the cubital fossa is most lateral?
Radial nerve
The carpal tunnel is a narrow passageway found on the _________ surface of the _______
Anterior
Wrist
The carpal tunnel is formed by which two layers?
A deep carpal arch
A superficial flexor retinaculum
What forms the carpal arch laterally?
Scaphoid and trapezium tubercles
What forms the carpal arch medially?
Hook of the hamate and the pisiform
What is the flexor retinaculum? Where does it originate and insert?
Thick connective tissue forming the roof of the carpal tunnel
Originates on the lateral side and inserts on the medial side of the carpal arch
What lines up with entrance of the carpal tunnel?
The distal wrist crease
What nerve travels in the carpal tunnel?
Median nerve
What tendons travel in the carpal tunnel?
Tendon of the flexor pollicis longus
4 tendons of the flexor digitorum profundus
4 tendons of the flexor digitorum superficialis
How are the tendons covered in the carpal tunnel?
The 8 tendons are covered by a single synovial sheath
The tendon for the flexor pollicis longs has its own synovial sheath
What is the purpose of sheaths surrounding the tendons?
Allows free movement of the tendons
Once it passes through the carpal tunnel the median nerve divides into which 2 branches?
Recurrent branch
Palmar digital nerves
The palmar digital nerves gives sensory innervation to…
The palmar skin and dorsal nail beds of the lateral three and a half digits
The palmar digital nerves provide motor innervation to…
The lateral two lumbricals
What does the recurrent branch supply?
The thenar muscle group
What causes carpal tunnel syndrome?
Compression of the median nerve in the carpal tunnel
If untreated carpal tunnel syndrome can result in?
Weakness and atrophy of the thenar muscles
What can cause carpal tunnel syndrome?
Thickened ligaments and tendon sheaths
What are some clinical features of carpal tunnel syndrome?
Numbness, tingling and pain in the distribution of the median nerve
What test can be done for carpal tunnel syndrome?
Tinel’s sign - tapping the nerve in the carpal tunnel to elicit pain
What is the treatment for carpal tunnel syndrome?
A splint holding the wrist in dorsiflexion overnight
Otherwise corticosteroid injections or surgical decompression
Which branch of the median nerve is spared in carpal tunnel syndrome? Why?
Palmar cutaneous nerve
Given off prior to the carpal tunnel
The anatomical snuffbox is located at the level of the __________ bones and is best seen when the thumb is ______________
Carpal
Abducted
What forms the medial border of the anatomical snuffbox?
Tendon of the extensor pollicis longus
What forms the lateral border of the anatomical snuffbox?
Tendons of the abductor pollicis longus and extensor pollicis brevis
What forms the proximal border of the anatomical snuffbox?
The styloid process of the radius
What forms the floor and roof of the anatomical snuffbox?
Scaphoid and trapezium
Skin
What are the main contents of the anatomical snuffbox? (3)
Radial artery
Branch of the radial nerve
Cephalic vein
Where does the radial artery pass in the anatomical snuffbox?
Crosses the floor in an oblique manner
What pulse can be palpate in the anatomical snuffbox? How?
Radial pulse
Placing two fingers on the proximal portion of the anatomical snuffbox
What branches of the radial nerve pass through the anatomical snuffbox? What do they innervate?
Terminal branches of the superficial branch of the radial nerve
The skin of the lateral 3 and a half digits on the dorsum of the hand and the associated palm area
What two bones articulate in the anatomical snuffbox to form part of the wrist joint?
Scaphoid and the radius
If localised pain is reported in the anatomical snuffbox what is the most likely cause?
Scaphoid fracture
What most commonly causes scaphoid fracture?
FOOSH
The blood supply of the scaphoid runs __________ to _________. What is the clinical significance of this?
Distal to proximal
Fracture can disrupt the blood supply in the proximal portion - if this isn’t revascularised it can result in avascular necrosis and future arthritis
