Upper Limb 1 Flashcards
What forms the lateral side of the axillary pyramid
The intertubercular groove of the humerus
What forms the posterior wall of the axilla
The subscapularis
Pectoralis minor
Latissmus dorsi
What forms the anterior side of the axillary pyramid
Pectoralis major
Subclavius
What forms the medial side of the axillary pyramid
Intercostal muscles and ribs
Seratus anterior
What forms the top of the axillary pyramid
- lateral border of first rib
- superior border of scapula
- posterior border of clavicle
Which nerve roots converge to form the upper trunk of the brachial plexus
C5 and C6
What nerve(s) form(s) the middle trunk of the brachial plexus
C7
What nerves converge to form the lower trunk of the brachial plexus
C8 and T1
Which muscles is the brachial plexus roots in between
Posterior and anterior scalene muscles
What forms the brachial plexus
VENTRAL RAMI OF C5, C6, C7, C8 and T1
Which cord in relation to the axillary artery gives rise to the musculocutaneous nerve
Lateral
Root value of the lateral cord of the brachial plexus
C5, C6 and C7
What does the median nerve arise from
The lateral and medial cords
Which nerves does the posterior cord of the brachial plexus give rise to
Axillary and radial nerves
Which cord does the ulnar nerve arise from
The medial cord
How would you cause erb’s palsy
injury to the upper trunk
Hyperextension of neck from shoulder
Falling on shoulder, birth injury or during anaesthesia
What would cause klumpke’s palsy
Injury at the nerve roots C8 and T1 - falling from a tree
Symptoms of erb’s palsy
Waiter’s tip
Medially rotated with wrist flexed
Which muscles are supplied by nerve roots C5 and C6
The upper trunk
- Supraspinatus, infraspinatus,
- Biceps brachi, coracobrachialis, deltoid, teres minor
Which muscles are affected by klumpke’s palsy
Intrinsic muscles of the hand and ulnar flexors of the wrist and fingers
What are the main branches of the brachial plexus
Musculocutaneous Axillary Radial Median Ulnar
Which nerve runs closest with the brachial artery
The median nerve
When does the subclavian artery change into the axillary artery
Lateral border of the first rib
Main contributor of the deep palmar arch
Radial artery
Main contributor of superficial palmar arch
Ulnar artery
Which of these veins is more lateral
- cephalic or basilic
Which vein connects these 2 veins
Cephalic
Median cubital vein
Where does the median cubital vein shunt blood to and from
From the cephalic vein to the basilic vein
What are the distinct groups of axillary lymph nodes
- Anterior/pectoral
- Posterior/subscapular
- Apical
- Central
- Lateral
Where would an infection from the little finger spread
Lateral group of lymph nodes
Where would an infection in the scapular region spread to
Posterior/subscapular group of lymph nodes
Where would the upper medial quadrant of the breast drain to
Anterior group of lymph nodes
Where do the upper limb and pectoral girdle articulate with the axial skeleton
Sternoclavicular joint
Where is the easiest place to break the clavicle
Junction between middle 1/3 and lateral 1/3
What muscles attach to the coracoid process
Originate from?
Biceps brachi (short head) Pectoralis minor
Coracobrachialis
Which bone does the acromion of the scapula articulate with
The clavicle
–> acromioclavicular joint
What type of joint is the acromioclavicular joint
Synovial plane
What type of joint is the sternoclavicular joint
Synovial saddle
Which muscles elevate the scapula
- Trapezius - superior part
- levator scapulae
Which muscles depress the scapula
Trapezius - inferior part
Which muscle protracts the scapula
Serratus anterior
Which muscle retracts the scapula
Trapezius (middle) and rhomboids
Which muscles rotate the scapula to elevate the glenoid cavity
(- after the first 30 degrees of movement occurring at the glenohumeral joint)
Descending and ascending trapezius work together??
Which muscles rotate the scapula to depress the glenoid cavity
(- after the first 30 degrees of movement occurring at the glenohumeral joint)
Inferior trapezius and inferior part of serratus anterior
Why is the glenohumeral joint stable despite the humerus being much larger than the glenoid fossa
The glenoid fossa is deepened by a fibrocartilaginous rim called the glenoid labrum
Name the ligaments of the glenohumeral joint
- coracohumeral ligament
- coracoacromial ligament
- glenohumeral ligaments
What prevents upper displacement of the humeral head from the glenoid fossa
The coracoacromial arch made up of the acromion and coracoid process of the scapula and the coracoacromial ligament
Which part of the shoulder joint is weakest
Anterior - is not protected by muscles or ligaments
Name the bursae around the shoulder joint
- subacromial
- subscapular
What is the role of the subacromial bursa
Supports deltoid and supraspnatous muscles
Where is the subacromial bursa
Inferior to the deltoid and acromion and superior to the supraspnatous tendon and joint capsule
Which bursa is located between the subscapularis tendon and the scapula
Subscapular bursa
Name the rotator cuff muscles
Supraspinatous
Infraspinatus
Teres minor
Subscapularis
What is the function of the rotator cuff muscles
Hod the humeral head in the glenoid cavity of scapula during all movements of the shoulder
What movements of the glenohumeral joint are initiated by the rotator cuff muscles
Subscapularis, teres minor and infraspinatus all involved in rotation
Supraspinatous involved in abduction of the arm
What is the origin of the deltoid muscle
Lateral spine of the scapula across the acromion to the lateral third of the clavicle
Action of the anterior fibres of the deltoid
Flexes and medially rotates at the shoulder joint
Action of the middle fibres of the deltoid
Abduction at the shoulder joint
Action of the posterior fibres of the deltoid
Extension and lateral rotation at the shoulder joint
Which nerve supplies the deltoid muscle
Axillary
Which nerve is at risk from a surgical neck of humerus fracture
Axillary nerve
Where would you test for loss of sensation for the axillary nerve
Lateral side of the arm over the deltoid area
- dermatomes C5 and C6
Where do the fibres of the pectoralis major originate
Medial third of clavicle, the sternum and ribs
Action of the Pectoralis major on the shoulder joint
To adduct and medially rotate the humerus
Which vein is found in the deltopectoral triangle
- this is the space between the deltoid and pectoralis major muscle
- subclavian
Action of the serratus anterior
- Protraction of the scapulae
- stabilises the scapulae during limb movements to keep it pulled against the thoracic cage
What is the nerve supply to the serratus anterior muscle
Long thoracic nerve - C5, C6 and C7
What clinical sign is viewed when the long thoracic nerve is damaged
Winging of the scapulae
During what procedure is the long thoracic nerve at risk of damage
- Radical mastectomies
- Also become damage by damage to the shoulder, repetitive movements involving the shoulder, structures becoming inflamed and pressing on the nerve
What is the nerve supply of the pectoralis major muscle
Medial and lateral pectoral nerves from the brachial plexus
Attachments of the pectoralis major muscle
- The clavicle (clavicular head)
- The sternum and ribs (sternocostal head)
- Intertubercular groove of the humerus
Innervation of the pectoralis minor
Medial pectoral nerve
Attachments of the pectoralis minor muscle
- Anterior surface of ribs 3-5
- coracoid process of scapula
–> imagine as a bridge that vessels passing into the upper limb must travel underneath
Innervation of the trapezius muscle
Accessory spinal nerve - CN XI
What is the action of the teres major on the shoulder joint
Adducts and medially rotates shoulder joint
Action of the latissmus dorsi on the shoulder joint
Extends, adducts and medially rotates - raises body or arms during climbing
Which muscles flex the shoulder joint
- Anterior of deltoid
- biceps brachi
- pectoralis major
Which muscles extend the shoulder joint
- latissmus dorsi
- teres major
- long head of triceps
- posterior fibres of deltoid
Which muscles adduct the shoulder joint
- Pectoralis major and minor
- ## latissmus dorsi
Contents of the axilla
Axillary artery Axillary vein Brachial plexus Auxiliary lymph nodes Coracorbrachialis and biceps brachi
