Anatomy of Limbs 2 - Shoulder and Arm Flashcards
The supraspinous and infraspinous fossae are separated by what structure in the scapula?
Spine of scapula / acromion
What lies just medial to the coracoid process?
Suprascapular notch
What is the large fossa on the costal surface of the scapula called?
Subscapular fossa
In the humerus, is the anatomical neck or surgical neck more commonly damaged?
Surgical neck
What are the anterior pectoral girdle muscles?
- Pec major
- Pec minor
- Subclavius
- Serratus anterior (runs between anterior and posterior)
What are the proximal attachments of the pec major?
- Medial 1/3rd of the clavicle
- Sternum
- Costal cartilages
What is the distal attachment of the pec major?
Lateral lip of the intertubercular sulcus (humerus)
What does the pec major do?
Adducts and medially rotates the humerus
What is the distal attachment of the pec minor?
Coracoid process of the scapula
Where is the proximal attachment of the pec minor?
Chostocondral joints
What is the purpose of the subclavius muscle?
Anchors the clavicle
From where to where does the serratus anterior run?
Medial border of the scapula to anterior attachments on the ribs
What nerve supplies the serratus anterior?
Long thoracic nerve
What are the posterior pectoral girdle muscles?
- Trapezius
- Lat dorsi
- Levator scapulae
- Rhomboids
What nerve supplies motor innervation to the trapezius?
Spinal accessory nerve (XI)
What nerve supplies the lats?
Thoracodorsal nerve
What does the latissimus dorsi do?
Extension, adduction and rotation of the humerus
Pulls body towards arms in climbing
Important in rowing
What muscle supplies the rhomboids?
Dorsal scapular nerve
What do the rhomboids do?
Retracts, rotates and fixes the scapula
What does the levator scapulae do?
Elevates and rotates the scapula
What nerves supply the elevator scapulae?
Dorsal scapular nerve ( & C3 /C4)
What are the intrinsic shoulder muscles?
- Deltoid
- Teres Major
- Rotator cuff muscles
What are the rotator cuff muscles
- Supraspinatus
- Infraspinatus
- Teres minor
- Subscapularis
What does the rotator cuff muscle do?
Acts to fix head of humerus in the glenoid fossa - depresses the humeral head
What is the supraspinatus for?
Abduction of the arm for the first 15 degrees then deltoid takes over
What does the teres major do (not rotator cuff)
Adducts and medially rotates
What nerve innervates the teres major?
Lower sub scapular nerve
Both the teres major and the latissimus Dorsi have the same attachment, where?
Inferior angle of the scapula to the floor and medial lip of inter tubercular sulcus of humerus
In the anterior compartment of the arm, what muscles are present?
Biceps
Brachialis
Coracobrachialis
What nerve supplies the anterior compartment of the arm?
Musculocutaneous nerve
The biceps consists of 2 heads. What are they and where do they run?
Short head, medial.
Long head, lateral (has longer tendon which runs through bicipital groove and across shoulder joint) - attaches to supraglenoid tubercle
The biceps have two distal attachments, where?
- To radial tuberosity
2. Also aponeurosis which merges with connective tissue in that region
Where does the corachobrachialis attach to proximally?
To the coracoid process (scapula) - it runs down the medial end of the humerus
Where does the brachialis muscle attach?
Attaches to anterior shaft of the humerus and runs to the coronoid process of the ulna
What is the brachialis used for?
Flexion
What muscles are present in the posterior compartment of the arm?
Triceps, Anconeus.
Both supplied by radial nerve
Where does the long head of triceps attach?
Infraglenoid tubercle
Where does the lateral and medial head of the triceps attach?
To the shaft of the humerus
Distally, where does the triceps tendon attach/
Olecranon process of ulna
Where is the anconeus attached?
Lateral epicondyle of the humerus and also upper shaft of ulna
What is the anconeus for>
Stabilising the elbow joint
Glenohumeral joint is between what?
It is the shoulder joint, between glenoid fossa and humerus
Which 4 joints form the pectoral girdle?
- Scapulothoracic joint
- Acromioclavicular joint
- Gleno-humeral jont
- Sterno-clavicular joint
What is the cartilage that deepens the glenoid fossa (which is quite shallow?)
Labrum
What is the main stabiliser of the glenohumeral joint?
Muscle action (e.g. rotator cuff)
What direction does dislocation of the shoulder joint usually occur?
Downwards
What are the 3 movements of the scapulothoracic joint?
- Elevation/depression
- Protraction/retraction
- Rotation of the scapula
Describe the progression of arteries in the axilla and arm
- Subclavian artery - passes over first rib to become —-
- Axillary artery - upon reaching lower border of teres major it becomes —-
- Brachial artery —-gives of a large branch in the arm (profound brachii) and then divides into Ulnar and radial arteries
What are the superficial veins in the arm?
Cephalic (lateral) and basilic (medial) veins
What does the basilica vein join with to form the axillary vein in the arm?
(Deep) venae comitantes
Where does the cephalic vein join the axillary vein?
Axilla
Where does the axillary vein become the subclavian vein?
At level of the first rib
Why are axillary lymph nodes important?
They drain the breast - lymphedema may occur if removed in breast cancer
Which nerve roots constitute the brachial plexus?
C5 - T1
Which nerve goes behind the elbow?
The ulnar nerve
Which nerve supplies deltoid and teres minor?
Axillary nerve
