Flashcards in Upper Limb 1 Deck (61):
What forms the anterior, posterior, medial and lateral walls of the axilla?
-Pectoralis Major and minor
-Teres Major and Latissimus dorsi
-Thoracic wall and serratus anterior
-Intratubercular sulcus of the humerus
The axillary artery is the continuation of which artery?
At what anatomical point does the subclavian artery become the axillary artery?
Lateral border of the 1st rib
The axillary artery continues beyond the axilla as which vessel?
At what anatomical point does the axillary artery become the brachial artery?
Inferior border of the teres major
When may compression of the axillary artery be necessary?
Profuse bleeding occurs due to severe injury to the upper limb
What spinal nerve roots form the brachial plexus?
Which nerve roots form the upper trunk, middle trunk and lower trunk of the brachial plexus?
-C5 and C6
-C8 and T1
What is Erb's point and what is the clinical relevance of it?
Point of unison of C5 and C6 forming the upper trunk of the brachial plexus.
Injury commonly sustained at this point during birth or from a fall onto the shoulder.
Causes Erb's palsy resulting in characteristic waiter's tip appearance of the upper limb -> medialy rotated with wrist flexed
What muscles are effected by Erb's palsy?
What nerves supply them?
Injury to the lower trunk of the brachial plexus causes what?
(what is the cause of this injury, what is effected, what is it called)
-Intrinsic muscles of the hand
-Ulnar flexors of the wrist and fingers
Cause of injury is undue abduction of the arm
-Trying to grab a branch while falling
What forms the medial, posterior and lateral cords of the brachial plexus?
-Upper trunk and middle trunk
-Upper, middle and lower trunks
Musculocutaneous nerve comes from which brachial plexus cord?
Lateral cord once the branch for the median nerve is given off
What cords form the median nerve?
Lateral and medial cords give off fibres forming the median nerve
What nerves come from the posterior cord of the brachial plexus?
Axillary and radial nerve
Upper and lower subscapular nerve
What cord does the ulnar nerve come from?
Medial cord once fibres are given off for the median nerve
What are the branches of the lateral cord of the brachial plexus?
Lateral root of median nerve
What are the branches of the medial cord of the brachial plexus?
Medial root of median nerve
Medial cutaneous nerve of the arm
Medial cutaneous nerve of the forearm
What two veins arise at the dorsal venous arch and where on this arch?
Cephalic vein at lateral end
Basilic vein at medial end
The median cubital vein is a large communicating vein which shunts blood from where to where?
cephalic vein -> basilic vein
Where do lymphatic vessels from the upper limb drain?
Name the 5 distinct groups of axillary lymph nodes
Anterior or pectoral group
Posterior or subscapular group
Infection in the little finger will drain to lymph nodes where?
A boil in the scapular region will drain to lymph nodes where?
The medial and lateral portions of the breast drain lymph where?
Medial -> internal thoracic
Lateral -> axilla
Infection around the umbilicus (e.g. infected tattoo) would drain lymph where?
Above umbilicus -> axilla
Below umbilicus -> superficial inguinal
The entire upper limb and pectoral girdle articulate at one small joint only, which is this?
Which part of the clavicle is weakest and commonly breaks?
Junction of middle and lateral thirds
What type of synovial joint are the acromioclavicular (AC) and sternoclavicular (SC) joints?
Acromioclavicular -> plane
Sternoclavicular -> saddle
What is the scapulohumeral rhythm?
Consider abduction of the arm from the anatomical position.
Initially, all movement will be at the glenohumeral joint, but beyond about the first 30 degrees, for every 3 degrees of abduction, 2 degrees occurs at the shoulder joint and 1 degree at the scapulothoracic joint (2:1 ratio)
What muscles cause elevation of the scapula?
What muscles cause depression of the scapula?
Pectoralis major and minor
What muscles cause protraction of the scapula?
Pectoralis major and minor
What muscles cause retraction of the scapula?
What muscles cause rotation depressing the glenoid cavity?
Inferior part of serratus anterior
What is the glenoid labrum?
Rim of cartilage surrounding the socket of the glenoid cavity.
Doubles the glenoid depth and increases the surface area.
Acts as a "chock block" limiting glenohumeral translation
The coracohumeral ligament strengthens what aspect of the joint capsule
The coracoacromial arch is made up of what 3 structures?
Coracoid process of the scapula
Which bursa communicates with the shoulder joint cavity?
What is the role of the subacromial bursa?
Facilitates movement of the supraspinatus tendon under the coraco-acromial arch and of the deltoid over the joint capsule and the greater tubercle of the humerus
What movements of the glenohumeral joint are generated by the rotator cuff muscles?
Abduction, lateral and medial rotation
Where does the origin of the deltoid extend from?
Lateral spine of the scapula, across the acromion to the lateral 3rd of the clavicle
What do each of the fibres of the deltoid do?
Anterior fibres -> medially rotate and flexes at the shoulder joint
Middle fibres -> abduct at the shoulder joint
Posterior fibres -> extend and laterally rotate at the shoulder joint
What is the nerve supply to the deltoid?
Where could you test for loss of sensation in axillary nerve injury?
Shoulder badge region
Lateral side of proximal part of arm - C5 dermatome
Superior lateral cutaneous nerve of the arm
Where do the fibres of the pectoralis major originate?
Medial third of the clavicle, the sternum and ribs
What is the action of the pectoralis major on the shoulder joint?
Adduct and medially rotate the humerus at the glenohumeral joint
What is the deltopectoral triangle?
Why is it important?
Triangular space below the clavicle, between deltoid and pactoralis major muscle.
Subclavian vein is vound in this triangle for the insertion of central lines
What is the funtcion of the serratus anterior?
Protraction of the scapulae, but mainly serves to stabilise it during limb movements and to keep it pulled against the thoracic cage
What is the nerve supply to serratus anterior?
Long thoracic nerve
What clinical sign do you see when the long thoracic nerve is injured?
What do all the different fibres of the trapezius do to the scapula?
Superior fibres -> elevate
Middle fibres -> retract
Inferior fibres -> depress
What is the nerve supply to the trapezius?
What is the action of teres major on the shoulder joint?
Adducts and medially rotates
What is the action of latissimus dorsi on the shoulder joint?
Extends, adducts and medially rotates shoulder joint
What muscles flex the shoulder?
What muscles extend the shoulder?
What muscles adduct the shoulder?
What muscles abduct the shoulder?
Middle part of deltoid
What msucles cause medial or internal rotation of the shoulder?