Upper Limb 1 - Axilla, Neurovascular, Dermatomes, Pectoral Girdle & Rotator Cuff Muscles Flashcards
Which muscles make up the anterior wall of the axilla?
Pectoralis major
Pectoralis minor
Which muscles make up the posterior wall of the axilla?
Subscapularis
Which muscles make up the medial wall of the axilla?
Thoracic wall
Serratus anterior
What forms the lateral wall of the axilla?
Intertubercular groove of Humerus
What are the contents of the axilla?
Axillary artery
Axillary vein
Brachial plexus
Biceps brachii
Coracobrachialis
Axilliary lymph nodes
Which artery is the axilla artery a continuation of?
Subclavian artery
At what anatomical point does the axillary artery begin?
Edge of 1st rib
What is the name of the axillary artery once is leaves the axilla and passes the teres major muscle?
Brachial artery
At what anatomical point does the name of the brachial artery change?
Cubital fossa
When there is an infection of the upper limb, what group of lymph nodes become enlarged?
Axillary lymph nodes
The brachial plexus is formed from the ventral rami of which nerve roots?
C5,6,7,8 and T1
Which nerve roots form the upper trunk?
C5 and C6
Which nerve roots form the middle trunk?
C7
Which nerve roots form the lower trunk?
C8 and T1
What is Erb’s point and what is its clinical relevance?
Erb’s point - a point found on the upper trunk of the brachial plexus, 2-3cm above the clavicle
Clinical relevance - Commonly damaged during chilbirth or falling onto the shoulder
What condition does damage to Erb’s point/upper trunk cause?
Erb’s palsy/waiters tip appearance
What muscles are affected in Erb’s palsy?
1 - Supraspinatus
2 - Infraspinatus
3 - Subclavius
4 - Biceps brachii
5 - Brachialis
6 - Coracobrachialis
7 - Deltoid
8 - Teres minor
What clinical condition results from damage to the lower trunk of the brachial plexus?
Klumpke’s palsy
What muscles are affected by Klumpke’s palsy?
Intrinsic muscle of hand
Ulnar flexors of wrist and fingers
In relation to which vessel are the cords of the brachial plexus named?
Axillary artery
What are the names of the cords of the brachial plexus?
Lateral
Posterior
Medial
What divisions form the cords of the brachial plexus?
Lateral cord - anterior division of superior trunk and anterior division of median trunk
Posterior cord - posterior divisions of superior, middle and inferior trunks
Medial cord - anterior division of inferior trunk
What are the major arteries of the upper arm?
Subclavian artery
Axillary artery
Brachial artery
Ulnar artery
Radial artery
What are the major veins of the upper arm?
Cephalic vein
Basilic vein
Median cubital vein (connects cephalic and basilic veins)
What is the clinical significance of the veins of the upper limb?
They are used for IV injections and drawing blood for testing
At their distal end, from which structure do the cephalic and basilic veins arise?
Dorsal venous arch
Between which 2 veins does the median cubital vein shunt blood?
Cephalic and basillic vein
Which dermatomal level innervates the thumb?
C6
Which dermatomal level innervates the index and middle finger?
C7
Which dermatomal level innervates the ring and little finger?
C8
If an area of the upper limb becomes infected, to where is the most likely location the lymphatic fluid will drain?
Axillary lymph nodes
If there is an infection of the little finger of the upper limb, to which group of lymph nodes would the infection spread?
Axillary
If there is a boil on the scapular region, to which group of lymph nodes would the infection spread?
Axillary
If there was cancer in the medial part of the breast, to which group of lymph nodes would the cancer likely spread?
Internal thoracic (mammary)
If there was cancer in the lateral part of the breast, to which group of lymph nodes would the cancer most likely spread?
Axillary
If there was an infection of the skin just above the umbilicus, to which group of lymph nodes would the infection most likely spread to?
Axillary
If there was an infection of the skin just below the umbilicus, to which group of lymph nodes would the infection most likely spread to?
Superficial inguinal
At which joint does the upper limb articulate with the pectoral girdle?
Glenohumeral joint
On which end of the clavicle is the conoid tubercle located? Humeral or sternal end?
Humeral/acromial end
What type of joint is the acromioclavicular joint?
Plane
What type of joint is the sternoclavicular joint?
Saddle
Which joints are involved in the movement of the pectoral girdle?
Acromioclavicular
Sternoclavicular
Glenohumeral
What is the scapulo-humeral rhythm?
2:1
After the first 30 degrees of abduction of the arm, 2 degrees of movement occurs at the shoulder joint and 1 degree at the scapula-thoracic joint
Which muscles are involved in elevation of the scapula?
Trapezius
Levator Scapulae
Serratus Anterior
Which muscles are involved in depression of the scapula?
Latissimus dorsi
Pectoralis Major
Pectoralis Minor
Which muscles are involved in protraction of the scapula?
Levator scapulae
Serratus Anterior
Which muscles are involved in retraction of the scapula?
Trapezius
Rhomboids
Latissimus Dorsi
What type of joint is the gleno-humeral joint?
Ball and socket synovial joint
What are the components of the gleno-humeral joint?
Head of Humerus
Glenoid cavity of Scapula
What is the name of the cartilage surrounding the joint?
Glenoid labrum
What is the function of the glenoid labrum?
It deepens the glenoid cavity, therefore reducing the chances of shoulder dislocation
What are the ligaments that stabilise the shoulder joint?
Coracohumeral ligament
Coracoacromial ligament
Glenohumeral ligament
What structures provide cushioning to joints?
Bursae
What common sporting injury damages the subacromial bursa?
Bursitis
What are the 4 rotator cuff muscles?
Infraspinatus
Supraspinatus
Subscapularis
Teres Minor
What movements of the glenohumeral joint do the rotator cuff muscles perform?
Abduction
Lateral + medial rotation
What is the most important role of the rotator cuff muscles?
To keep the humerus head within the glenoid fossa
What action do the anterior fibres of the deltoid perform?
Flex at Shoulder
What action do the middle fibres of the deltoid perform?
Abduction at shoulder joint
What action do the posterior fibres of the deltoid perform?
Extend of the arm at the shoulder
What nerve supplies the deltoid muscle?
Axillary nerve
What common injury results in the axillary nerve becoming trapped and damaged?
Dislocation of the shoulder
If the axillary nerve became damaged due to shoulder dislocation, where would you test for loss of sensation?
Test for loss of sensation over the deltoid muscle
Where do the fibres of pectoralis major originate from?
- Medial 1/3 of clavicle
- Sternum
- Ribs
What are the actions of pectoralis major on the shoulder joint?
Adduct and medially rotate the humerus at glenohumeral joint
Which vein (important for placement of central lines) is found within the deltopectoral triangle between deltoid and pectoralis major?
Cephalic vein
What is the nerve supply of serratus anterior?
Long thoracic nerve
What clinical sign is observed when the long thoracic nerve is damaged?
Winging of the Scapula
During which procedure is the long thoracic nerve most commonly injured?
Lymph node biopsy
What action do the superior fibres of the trapezius perform on the scapula?
Elevate and rotate Scapula
What action do the middle fibres of the trapezius have on the scapula?
Retract scapula
What action do the inferior fibres of the trapezius have on the scapula?
Depress the scapula
Which nerve innervates the trapezius muscle?
Accessory nerve
What are the actions of Teres Major on the shoulder joint?
Adducts shoulder and medially rotates arm
What are the actions of latissimus dorsi on the shoulder joint?
Extends, adducts and medially rotates shoulder joint
Which muscles perform flexion at the shoulder joint?
Pectoralis major
Anterior deltoid
Coracobrachialis
Which muscles perform extension at the shoulder joint?
Posterior deltoid
Latissimus dorsi
Which muscles perform adduction at the shoulder joint?
Pectoralis major
Lattisimus dorsi
Teres Major
Which muscles perform abduction of the shoulder joint?
Supraspinatus (0-15 degrees)
Middle deltoid (15-90 degrees)
Trapezius and Serratus Anterior (>90 degrees)
Which muscles perform internal rotation of the shoulder joint?
Subscapularis
Latissimus Dorsi
Pec major
Teres Major
Which muscles perform lateral rotation at the shoulder joint?
Teres minor and infraspinatus