"Shoulder and Arm" Questions Flashcards
What are the 3 bones from the shoulder girdle to the elbow?
Scapula
Clavicle
Humerus
What are the landmarks at the neck of the humerus?
Greater tubercle (laterally) Lesser tubercle (medially) Intertubercular sulcus (in between)
What is the name of the joint between the acromion and the clavicle?
Acromioclavicular joint
What are the two ends of the clavicle?
Acromial (at acromion)
Sternal (at sternum)
What are the borders and angles of the scapula?
Superior, lateral and medial borders
Inferior and superior angles (lateral “angle” is the acromion)
What are the two lateral extensions of the scapula where lots of muscles attach?
Coracoid process (anterior, looks like a hook) Acromion (posterior, articulates with clavicle)
What is the name of the space where the humerus articulates with the scapula?
Glenoid fossa/cavity
glenohumeral joint
What are the fossae of the scapula?
1 anterior 2 posterior
Anterior = subscapular fossa
Posterior divided by scapular spine into supraspinous fossa and infraspinous fossa
Where is the suprascapular notch?
Between superior angle of the scapula and the coracoid process (little dip)
Where is the head and neck of the scapula?
Laterally
Head is the lip of the glenoid cavity
Neck is just medial to that below the acromion
What are the 3 joints associated with the scapula?
Gleno-humeral joint
Acromio-clavicular joint
Scapulo-thoracic joint (physiological “joint” with chest wall via muscles)
How do you identify the orientation of a random clavicle bone?
There is a sternal and an acromial end and shaft is divided into medial 2/3rd lateral 1/3rd
Use the inferior surface markings
- impression for costoclavicular ligament is close to sternal end on inferior surface
- subclavian groove (for subclavius muscle) is around midpoint of inferior surface of the shaft)
- conoid tubercle at acromial end
- trapezoid line at acromial line (ridge on underside of acromial end)
Acromial end is usually slightly fatter and sternal end more cylindrical
What attaches at the conoid tubercle and the trapezoid line?
Conoid = coracoclavicular ligament Trapezoid = trapezoid ligament
What are the 4 nerves in contact with the humerus?
Axillary
Radial
Ulnar
Median
How can the median nerve be damaged?
Runs anterior to distal humerus
- damaged by fractures/dislocations around the elbow joint
How can the axillary nerve be damaged?
Winds around surgical neck of the humerus
- can be damaged in shoulder dislocations
How can the ulnar nerve be damaged?
Runs posterior to the medial epicondyle
- can be damaged in fractures/dislocations around the elbow joints
How can the radial nerve be damaged?
Runs in the radial groove
- can be damaged by fractures of the humeral shaft
Where are the two necks and the head of the humerus and which neck is more commonly damaged?
Head of humerus (inserts into glenoid cavity)
Anatomical neck - lip of bone just after head
Surgical neck - area between expanded head and narrow shaft, quite weak, easier to fracture
Surgical is more commonly fractured than anatomical.
Where is the radial groove and what is it formed from?
Wraps around to the posterior of the humerus
- starts as intertubercular sulcus (groove)
What is the ridge of bone called on the shaft of the humerus?
Deltoid tuberosity
What muscles attach to the intertubercular groove and where on it do they attach?
Pec. major attaches to lateral lip
Teres major attaches to medial lip
Lat. dorsi attaches to the floor
What joints is the pectoral girdle made up of?
Sterno-clavicular joint Acromio-clavicular joint Gleno-humeral joint Scapulo-thoracic joint (all of these are synovial joints except scapulo-thoracic)
What are the ligaments involved in the sterno-clavicular joint?
Sterno-clavicular ligaments
What are the ligaments involved in the acromio-clavicular joint?
- Acromio-clavicular ligament
- Coraco-clavicular ligament (conoid + trapezoid ligs.)
- Coraco-acromial ligament
What are the ligaments involved with the shoulder joint capsule? (glenohumeral joint)
- Gleno-humeral ligament (strengthens anterior capsule part)
- Coraco-humeral ligament (strengthens superior capsule part)
- Transverse humeral ligament (holds tendon of long head of the bicep in intertubercular sulcus)
Which muscles cause flexion at the shoulder joint?
Pec. major (clavicular head)
Deltoid (anterior fibres)
Coraco-brachialis
Biceps brachii
Which muscles cause extension at the shoulder joint?
Lat. dorsi
Deltoid (posterior fibres)
Which muscles cause abduction of the shoulder joint?
Supraspinatus (first 15 degrees)
Deltoid (central fibres) after first 15 degrees)
Which muscles cause adduction of the shoulder joint?
Pec. major
Lat. dorsi
Which muscles cause internal and external rotation of the shoulder joint?
Internal rotation = subscapularis
External rotation = infraspinatus, teres minor
Which muscles resist dislocation of the shoulder joint?
Rotator cuff muscles (hold humeral head against glenoid cavity)
Deltoid
Coracobrachialis
Short/Long head of biceps brachii
What are the three fossae of the distal humerus?
2 anterior 1 posterior
Anterior = coronoid (medial), radial (lateral)
Posterior = olecranon fossa
What are the four bony landmarks of the distal humerus?
Medial and lateral epicondyles
Trochlea (medial)
Capitulum (lateral)
What are the proximal/distal attachments of the pec major and what does it do?
Proximal attachments
- Clavicular head = anterior surface of medial 1/2 of clavicle
- Sternocostal head = anterior surface of sternum, first 7 costal cartilages, aponeurosis of external oblique
Distal attachment
- Lateral lip of intertubercular sulcus of humerus
Flexion, adduction and medial rotation of arm at glenohumeral joint
- clavicular head = flexion of extended arm
- sternocostal head = extension of flexed arm
What are the proximal/distal attachments of the pec minor and what does it do?
Proximal attachments
- Anterior surfaces and superior borders of ribs 3-5
Distal attachment
- Coracoid process of the scapula
Stabilises scapula by pulling tip of shoulder down (scapular depression) and pulls clavicle medially to stabilise sternoclavicular joint (SCJ)
What are the proximal/distal attachments of the subclavius and what does it do?
Proximal attachment
- first rib at costochondral junction (between rib/costal cartilage)
Distal attachment
- subclavian groove (inferior surface of middle 1/3rd of clavicle)
Pulls clavicle medially to stabilise the SCJ
What are the proximal/distal attachments of the serratus anterior and what does it do?
Proximal attachment
- lateral surface of ribs 1-8/9
Distal attachment
- costal surface of medial border of scapula
Protraction and rotation of the scapula, keeps medial border and inferior angle of scapula opposed to thoracic wall
What are the proximal/distal attachments of the trapezius and what does it do?
Proximal
- superior nuchal line, external occipital protuberance, medial margin of the ligament nuchae, spinous processes of C7-T12
Distal
- superior edge of the crest of the spine of the scapula, acromion, posterior border of lateral 1/3rd of clavicle
Elevates scapula, middle fibres retract scapula, lower fibres depress scapula
What are the proximal/distal attachments of the lat dorsi and what does it do?
Proximal
- spinous processes of T6-12, iliac crest, lower 3-4 ribs (ribs 8/9-12)
Distal
- floor of intertubercular sulcus of humerus
Adduction, medial rotation and extension of the arm at glenohumeral joint. “pulling” in general.
What are the proximal/distal attachments of the levator scapulae and what does it do?
Proximal
- transverse processes of C1+2, posterior tubercles of of transverse processes of C3+4
Distal
- posterior surface of the medial border of the scapula
Elevates scapula
What do the rhomboid muscles do?
Elevate and retract the medial border of the scapula
What do the rhomboid muscles do?
Elevate and retract the medial border of the scapula
What are the intrinsic muscles of the shoulder?
Deltoid
Teres major
Rotator cuff muscles
What are the rotator cuff muscles?
Supraspinatus
Infraspinatus
Subscapularis
Teres minor
What are the rotator cuff muscles?
Supraspinatus
Infraspinatus
Subscapularis
Teres minor
What are the muscles of the anterior compartment of the upper arm?
Biceps brachii
Coracobrachialis
Brachialis
Which nerve innervates the anterior compartment of the arm?
Musculocutaneous (C5/6)
What are the muscles of the posterior compartment of the upper arm?
Triceps brachii
Anconeus (stabilises elbow during supination and pronation)
Which nerve innervates the posterior compartment of the arm?
Radial nerve (C6/7/8)
What are the spinal nerve roots for supply of the arm?
C5,6,7,8 T1
What are the spinal nerve roots for supply of the arm?
C5,6,7,8 T1
What are the borders of the axilla?
Base - skin, subcut. tissue, fascia
Apex - lies between first rib, clavicle and superior border of subscapularis muscle
Anterior wall - pec major+minor
Posterior wall - scapula + subscapularis (superiorly) and teres minor + lat dorsi (inferiorly)
Medial wall - chest wall (1st to 4th ribs) + serratus anterior
Lateral wall - humerus (intertubercular sulcus so coracobrachialis and short head of biceps brachii are IN the axilla)
What are the contents of the axilla?
Axillary artery + its branches
Axillary vein + its tributaries
Lymphatic vessels and lymph nodes
Brachial plexus (nerves) + long thoracic nerve
Describe the path of the arterial supply to the arm and how these arteries change when they move over different structures.
Subclavian arises from brachiocephalic artery (right side of chest) or from aorta (left side of chest)
- it runs in the root of the neck and becomes the axillary artery as it passes the 1ST RIB
- it passes through the axillary region to become the brachial artery as it passes the inferior border of the TERES MAJOR muscle
- the brachial artery divides at the elbow into brachial and ulnar arteries
- the ulnar artery gives off the common interosseous artery down the middle of the forearm
How does the axillary artery divide in the axilla?
Divides into 3 with each part of the pec minor
Gives off a number of branches in the axilla
Where is there extensive arterial anastomosis in the arm?
Elbow
What does the brachial artery give off in the arm?
Profunda brachii artery
Many muscular branches
What is the mnemonic for the branches of the axillary artery?
Some Times Life Seems A Pain
What are the branches of the axillary artery?
Superior thoracic artery Thoraco-acromial artery Lateral thoracic artery Subscapular artery Anterior circumflex humeral artery Posterior circumflex artery
How is the venous drainage of the arm comprised?
Axillary vein (deep) formed from basilic vein (superficial) and the venae comitantes of the brachial artery. Axillary vein ends at the first rib where it becomes the subclavian vein Cephalic vein passes on the lateral aspect of the arm and terminates via passing deep in the delto-pectoral triangle to join the axillary vein
SO basically
basilic vein + venae comitantes medially + cephalic vein laterally = axillary vein which becomes the subclavian vein
What are the five groups of axillary lymph nodes and which do they all drain via?
1 - Apical 2 - Pectoral 3 - Subscapular 4 - Humeral 5 - Central
All drain via the Apical lymph nodes
Which two nerves can be damaged by surgical sampling of axillary lymph nodes (e.g. cancer etc)?
Thoracodorsal nerve - supplies lat dorsi, not too much disability produced if cut
Long thoracic nerve - supplies serratus anterior, cutting of these causes paralysis of serratus anterior and winging of the scapula
What is the lymph drainage comprised of, further down in the arm?
Superficial and deep lymphatics which run alongside the cephalic/basilic and deep veins respectively.
There are some delto-pectoral lymph nodes alongside the cephalic vein and some cubital lymph nodes at the elbow
BUT, ultimately, the lymph drains to the axillary lymph nodes
Where is the final lymphatic destination of lymph from the arm?
Subclavian lymphatic trunk
- right = right subclavian lymphatic duct
- left = thoracic duct
What is the brachial plexus and which rami/spinal roots does it originate from?
The plexus of nerves serving the upper limb
- formed from roots C5,6,7,8 and T1
What 5 parts does the brachial plexus consist of?
Roots Trunks Divisions Cords Branches
What are the important nerves the originate from the brachial plexus?
Long thoracic nerve Suprascapular nerve (infra/supraspinatus) Lateral pectoral nerve (pec major) Thoraco-dorsal nerve Axillary nerve Musculocutaneous nerve Ulnar nerve Median nerve Radial nerve
