VIVA: Anatomy - Upper limb Flashcards
Describe the superficial lymphatics of the upper limb
- Originate from lymphatic plexuses and ascend mostly with superficial cephalic and basilic veins*
- Some accompanying the basilic veins enter the cubital lymph nodes
- Efferent vessels from here drain to axillary lymph nodes*
- Lymphatics accompanying the cephalic veins enter the axillary lymph nodes with some entering deltopectoral lymph nodes earlier
*needed to pass
Describe the boundaries of the cubital fossa
Triangular fossa with boundaries (3/4 to pass):
- Superiorly: imaginary line between epicondyles
- Medially: lateral border pronator teres
- Laterally: medial border of brachioradialis
- Floor: brachialis and supinator
- Roof: deep fascia reinforced by bicipital aponeurosis, subcutaneous tissue and skin
In this photo, identify the contents of the cubital fossa
- Radial nerve* with superficial terminal branch (16)
- Biceps and tendon (3)
- Brachial artery* (4)
- Ulnar (17) and radial (13) arteries
- Median nerve* (12)
- Brachialis (5)
Describe the course of the ulnar nerve around the elbow
Passes through the elbow posterior to the medial epicondyle of the humerus
What clinical findings would you expect if the ulnar nerve is injured at the elbow?
Loss of sensation to*:
- Medial half of palm (palmar cutaneous branch)
- Medial one and a half fingers, and associated dorsal hand area (dorsal cutaneous branch)
- Palmar surface of the medial one and a half fingers (superficial ulnar branch)
Motor, unable to*:
- Flex and adduct hand at wrist (FCU)
- Flex DIPJ 4th and 5th digits (FDP III and IV)
- Flex and abduct 5th MCPJ (hypothenar muscles: abductor digiti minimi, opponens digiti minimi, flexor digiti minimi)
- Adduct thumb (adductor pollicis, half of flexor pollicis brevis)
- Abduct and adduct 4th and 5th fingers (interosseous muscles, 3rd and 4th lumbricals)
*sensory + 2/5 motor to pass
How would you differentiate an ulnar nerve lesion at the elbow from one at the wrist?
More pronounced claw hand if lesion is more distal, as FCU and FDP preserved
Identify the components of the brachial plexus
6 to pass:
- Axillary nerve (1)
- Lateral cord (6)
- Lateral root of median nerve (8)
- Medial cord (12)
- Medial cutaneous nerve of arm (13)
- Medial cutaneous nerve of forearm (14)
- Medial root of median nerve (16)
- Musculocutaneous nerve (18)
- Posterior cord (20)
- Ulnar nerve (26)
What are the nerve roots that make up the posterior cord of the brachial plexus?
C5-8, T1
What are the terminal branches of the posterior cord and what do they supply?
Axillary nerve (C5,6)*:
- Glenohumeral joint
- Deltoid, teres minor
- Skin over inferior aspect of deltoid
Radial nerve (C5-T1)*:
- All muscles in posterior compartment of arm and forearm
- Skin over posteroinferolateral arm, posterior forearm and dorsum of hand lateral to ring finger
Other branches:
- Upper scapular nerve (C5): supplies subscapularis
- Lower subscapular nerve (C6): supplies inferior part of subscapularis and teres major
- Thoracodorsal nerve (C6-8): supplies latissimus dorsi
*needed to pass + example of supply
What does the musculocutaneous nerve supply?
Motor:
- Muscles of anterior arm (biceps brachii, brachialis, coracobrachialis)
Sensory:
- Skin over lateral forearm (becomes the lateral cutaneous nerve of the forearm after giving off its motor supply)
Apart from wrist extensor weakness, what other functions may be lost with a radial nerve lesion in the axilla?
1 to pass:
- Finger extension
- Sensory loss over radial side of dorsum of hand
A 60 year old alcoholic man is brought to ED after being found slumped in a chair. He is noted to have a wrist drop. Identify the nerve most likely injured.
Radial nerve (21)
Identify the main features of this bone
- Glenoid cavity*
- Spine*
- Supra and infraspinous fossae*
- Subscapular fossa*
- Acromion*
- Coracoid process*
- Neck
- Facet for clavicle
- Suprascapular notch
- Supra and infraglenoid tubercles
- Deltoid tubercle
- Inferior angle
- Medial border
- Lateral border
- needed to pass
Demonstrate on this bone the attachments of the scapulohumeral muscles
- Deltoid: acromion and spine of scapula*
- Supraspinatus: supraspinous*
- Infraspinatus: infraspinous fossa*
- Teres minor: middle part of lateral border
- Teres major: posterior surface of inferior angle
- Subscapularis: subscapular fossa*
*needed to pass
What are the actions of the individual rotator cuff muscles?
3/4 to pass:
- Supraspinatus: abduction
- Infraspinatus: lateral rotation
- Teres minor: lateral rotation
- Subscapularis: medial rotation
What are the articulating surfaces in the shoulder joint?
Ball-and-socket synovial joint with:
- Rounded head of humerus*
- Shallow glenoid cavity of scapula* (deepened by labrum)
*needed to pass
What structures stabilise the shoulder joint?
- Rotator cuff muscles (supraspinatus, infraspinatus, teres minor, subscapularis)*
- Fibrocartilaginous glenoid labrum (deepens the joint)
- Coraco-acromial arch (formed by coraco-acromial ligament, resists superior displacement of humerus)
- Anterior glenohumeral ligaments (stabilise the joint anteriorly)
- Coraco-humeral ligament (supports superior joint capsule)
- Transverse humeral ligament (between two tubercles of humerus; holds tendon of long head of biceps in place)
*3/4 rotator cuff muscles + 2 others to pass (need to show understanding that there are different elements that contribute to stability)
What muscles are responsible for abduction and adduction of the shoulder?
Abduction:
- Supraspinatus* (initiates)
- Deltoid* (especially acromial part)
- With upward movement of scapula
Adduction:
- Pectoralis major* and latissimus dorsi* acting in concert
- Teres major* and long head of triceps* (synergists)
*2/4 to pass
What muscles are responsible for other movements of the shoulder (besides abduction and adduction)?
Flexion:
- Pectoralis major (clavicular head)
- Deltoid (clavicular and anterior acromial parts)
- Coracobrachialis (synergist)
Extension:
- Deltoid (spinal part)
- Latissimus dorsi
- Teres major
- Long head of triceps (synergists)
Medial rotation:
- Subscapularis
- Pectoralis major
- Latissimus dorsi
- Teres major
- Deltoid (clavicular part; synergist)
Lateral rotation:
- Infraspinatus
- Teres minor
- Deltoid (spinal part; synergist)
Circumduction
Outline the bursae of the shoulder joint
- Subscapular bursa:
- Between neck of scapula and subscapularis tendon
- Protects tendon - Subacromial (subdeltoid) bursa:
- Between acromion, coraco-acromial ligament and deltoid superiorly, and supraspinatus tendon and joint capsule inferiorly
- Facilitates movement of supraspinatus tendon
Identify the features on this model of a shoulder
Bones:
- Humerus * (with humeral head)
- Scapula * (with coracoid process *, acromion *, spine and body)
- Clavicle *
Joints:
- Glenohumeral *
- Acromioclavicular *
Ligaments:
- Coracoclavicular * (with conoid and trapezoid parts; most important for stability of ACJ)
- Acromioclavicular * (from top of clavicle to acromion)
- Glenohumeral ligament (reinforce anterior part of capsule from glenoid labrum to humerus)
Tendons:
- Long head of biceps tendon *
*needed to pass
What anatomical structures confer stability to the shoulder joint?
3/5 to pass:
- Joint capsule with fusion of the tendons of scapular/rotator cuff muscles
- Ligamentous: glenohumeral and coracohumeral ligaments
- Coracoacromial arch superiorly created by coracoacromial ligament
- Deepening of glenoid cavity by glenoid labrum
- Tendons of long head of biceps and triceps
What structures can be damaged by shoulder dislocation?
- Joint capsule and glenoid labrum damage (results in recurrent dislocation)
- Axillary nerve * lies below joint capsule (results in axillary nerve palsy: regimental badge sensory loss and inability to abduct shoulder past 15 degrees)
- Associated fracture of greater tubercle
*needed to pass
Name the ligaments of the shoulder and describe how they stabilise the joint
2/4 to pass:
1. Glenohumeral ligaments (superior, middle and inferior):
- Consists of three bands, which runs with joint capsule from glenoid fossa to anatomical neck of humerus
- Acts to stabilise the anterior aspect of the joint
2. Coracohumeral ligament:
- Attaches base of coracoid process to the greater tubercle of the humerus
- Supports the superior part of the joint capsule
3. Transverse humeral ligament:
- Spans distance between two tubercles of humerus
- Holds the tendon of long head of biceps in the intertubecular groove
4. Coracoacromial ligament:
- Runs between the acromion and coracoid process of the scapula, forming the coracoacromial arch
- This overlies the shoulder joint, preventing superior displacement of the humeral head
Identify the numbered bony features depicted on this photo of a humerus
6/10 to pass:
1. Anatomical neck
2. Deltoid tuberosity
3. Greater tubercle
4. Groove for radial nerve
5. Head
6. Intertubercular groove
7. Lateral lip of intertubercular groove
8. Lesser tubercle
9. Medial lip of intertubercular groove
10. Surgical neck