Region 5 - Shoulder and Arm Flashcards
What are the origins of the pectoralis major?
Clavicle (anterior surface of medial half)
Costal cartilages of ribs 1-6
Anterior sternum
What is the insertion of the pectoralis major?
Outer lip of bicipital groove of humerus
What are the functions of the pectoralis major?
Flexion of arm
Adduction of arm
Medial rotation of humerus
What is the innervation to the pectoralis major?
Medial pectoral nerve (C8-T1) (from medial cord)
Lateral pectoral nerve (C5-C7) (from lateral cord)
What are the origins of the pectoralis minor?
3rd-5th ribs
Where does the pectoralis minor insert?
Coracoid process
What are the functions of the pectoralis minor?
Stabilises scapula by pulling it anteroinferiorly
Can elevate ribs if shoulder fixed
What is the innervation to pectoralis minor?
Medial pectoral nerve (C8-T1) (from medial cord)
What is the origin of serratus anterior?
Lateral surface of upper 8 ribs
What is the insertion of serratus anterior?
Anterior surface of medial border of scapula
What are the functions of serratus anterior?
Protracts scapula
Rotates scapula
What is the innervation to serratus anterior?
Long thoracic nerve (C5-C7)
What are the origins of the trapezius?
Medial 1/3 of superior nuchal line (occipital bone)
Nuchal ligament
Spinous processes of C7-T12
What are the insertions of the trapezius?
Lateral 1/3 of clavicle
Acromion
Spine of scapula
What are the functions of the trapezius?
Ascending part - Depresses scapula
Transverse part - Retracts scapula
Descending part - Elevates scapula and rotate glenoid cavity
What is the innervation to the trapezius?
Motor - Spinal accessory (CN XI)
Pain - Cervical plexus (C3-C4)
What are the origins of latissimus dorsi?
Iliac crest
Thoracolumbar fascia
SPinous processes of T7-T12
What is the insertion of latissimus dorsi?
Floor of bicipital groove
What are the functions of latissimus dorsi?
Extension of arm
Adduction of arm
Medial rotation
(All useful in climbing and chin-ups)
What is the innervation to latissimus dorsi?
Thoracodorsal nerve (C6-C8) from post. cord of brachial plexus
What are the origins of levator scapulae?
Posterior tubercles of transverse processes of C1-C4
What is the insertion of levator scapulae?
Medial border of scapula between superior angle and medial end of scapular spine
What are the functions of levator scapulae?
Elevates scapula (with trapezius)
Rotates glenoid cavity inferiorly
Laterally flex neck ipsilaterally (if shoulder fixed)
What is the innervation to levator scapulae?
Dorsal scapular nerve (C3-C5)
What are the origins of rhomboid major?
Spinous processes of T2-T5
What is the insertion of rhomboid major?
Medial border of scapula (from spine to inf. angle)
What are the origins of rhomboid minor?
Nuchal ligament
Spinous processes C7-T1
What is the insertion of rhomboid minor?
Medial end of scapular spine
What is the function of rhomboid major and minor?
Retract scapula
What is the innervation to rhomboid major and minor?
Dorsal scapular nerve (C4-C5)
What are the origins of deltoid?
Lateral 1/3 clavicle
Acromion
Spine of scapula
What is the insertion of the deltoid?
Deltoid tuberosity of humerus
What is the function of the anterior (clavicular) part of the deltoid?
Flexion of arm
Medial rotation of arm
What is the function of the middle (acromial) part of the deltoid?
Abducts arm (from 10-110 degrees)
What is the function of the posterior (spinal) part of the deltoid?
Extension of arm
Lateral rotation of arm
What is the innervation to deltoid?
Axillary nerve (C5-C6) from posterior cord of brachial plexus
What groove does the cephalic vein run in?
Deltopectoral groove
What is the origin of the teres major?
Lateral border of scapula (lower 1/3 on post. surface)
What is the insertion of teres major?
Medial lip of bicipital groove of humerus
What are the functions of teres major?
Adducts arm
Medial rotation of arm
What is the innervation to teres major?
Lower subscapular nerve (C5-C6) from posterior cord of brachial plexus
What is the origins of subclavius?
Sternal end of 1st rib
What is the insertion of subclavius?
Middle 1/3 of inferior surface of clavicle
What are the functions of subclavius?
Depress clavicle
Move clavicle anteriorly during abduction
What is subclavius innervated by?
Nerve to subclavius (C5-C6)
What are the 4 rotator cuff muscles?
Supraspinatus
Infraspinatus
Subscapularis
Teres minor
What is the general function that all 4 rotator cuff muscles share?
Prevent dislocation from a very shallow joint that has few other supporting structures
What is the origin of subscapularis?
Subscapular fossa (anterior scapula)
What is the insertion of subscapularis?
Lesser tubercle of humerus
What is the function of subscapularis?
Medially rotate arm
What is the innervation to subscapularis?
Upper and lower subscapular nerves (C5-C7) from posterior cord of brachial plexus
What is the origin of supraspinatus?
Supraspinatus fossa (of scapula)
What is the insertion of supraspinatus?
Superior facet of greater tubercle of humerus
What is the function of supraspinatus?
Abduct arm first 10-15 degrees
What is the innervation to supraspinatus?
Suprascapular nerve (C5-C6) from superior trunk of brachial plexus
What is the origin of infraspinatus?
Infraspinatus fossa
What is the insertion of infraspinatus?
Middle facet of greater tubercle of humerus
What is the function of infraspinatus?
Laterally rotates arm
What is the innervation to infraspinatus?
Suprascapular nerve (C5-C6)
What is the origin of teres minor?
Upper 2/3 of the lateral border of scapula
What is the insertion of teres minor?
Inferior facet of the greater tubercle of humerus
What is the function of teres minor?
Laterally rotates arm
What is the innervation to teres minor?
Axillary nerve (C5-C6) from posterior cord
What ligaments of the shoulder joint attach to the lesser tubercle?
Superior, middle and inferior glenohumeral ligaments
What ligament of the shoulder joint attaches to the greater tubercle?
Coracohumeral ligament
What is the function of the transverse humeral ligament?
Holds biceps tendon in place
What is the shape of the coracoclavicular ligament?
Conoid and trapezoid
What is the first superior branch of the subclavian artery?
Vertebral artery (off of superior surface)
What is the second superior branch of the subclavian artery?
Thyrocervical trunk (off of superior surface)
What is the first inferior branch of the subclavian artery?
Internal thoracic artery
What is the branch of the second part of the subclavian artery?
Costocervical trunk
What are some of the possible branches of the thyrocervical trunk?
Suprascapular
Dorsal scapular
Ascending cervical
Inferior thyroid
What are the borders of the quadrangular space?
Superior = Inferior margin teres minor Inferior = Superior margin teres major Medial = Lateral margin long head triceps Lateral = Surgical neck of humerus
What is contained in the quadrangular space?
Axillary nerve
Posterior circumflex humeral artery
What are the borders of the triangular hiatus/interval/space?
Superior = Inferior margin teres major Medial = Lateral margin long head triceps Lateral = Medial humerus
What are the contents of the triangular space?
Radial nerve
Profunda brachii artery
What muscles does the clavipectoral fascia enclose?
Subclavius
Pectoralis minor
What is the suspensory ligament of the clavipectoral fascia continuous with?
Axillary fascia
What pierces the clavipectoral fascia?
Cephalic vein
Thoracoaromial artery
Lateral pectoral nerve
What forms the anterior wall of the axilla?
Pectoralis major and minor
Subclavius
Clavipectoral fascia
What forms the floor of the axilla?
Skin (and into arm)
What forms the roof of the axilla?
Rib 1
Clavicle
Scapula
What forms the posterior wall of the axilla?
Subscapularis
Teres major
Latissimus dorsi
Long head of triceps brachii
What forms the lateral wall of the axilla?
Humerus
What forms the medial wall of axilla?
Serratus anterior
Wall of thorax
What are the contents of the axilla?
Vessels, nerves and lymphatics for upper limb Short head biceps Coracobrachialis Lymph nodes draining: - Upper limb - Mammary tissue Adipose
What does the basilic vein drain?
Posteromedial hand and foreaem
When does the basilic vein become the axillary vein?
Lower margin teres major
Which is more anterior in the axilla; the axillary artery or vein?
Vein
When does the axillary vein become the subclavian vein?
Lateral border rib 1
What veins join the axillary vein?
Brachial veins
Cephalis vein
How do the basilic and cephalic veins communicate?
Median cubital vein
Where does the axillary artery run from and to?
From lateral margin rib 1
To inferior margin teres major
Where is part 1 of the axillary artery?
Proximal to pectoralis minor
Where is part 2 of the axillary artery?
Posterior to pectoralis minor
Where is part 3 of the axillary artery?
Distal to pectoralis minor
What are the branch(es) of the first part of the axillary artery?
Superior thoracic artery
What are the branch(es) of the second part of the axillary artery?
Thoracoacromial artery
Lateral thoracic artery
What are the branch(es) of the third part of the axillary artery?
Subscapular artery
Anterior circumflex humeral artery
Posterior circumflex humeral artery
Where does the humeral group of axillary lymph nodes lie?
Posterior to axillary vein
Where does the pectoral group of axillary lymph nodes lie?
Inferior margin pectoralis minor
Where does the subscapular group of axillary lymph nodes lie?
Posterior axillary wall
Where does the central group of axillary lymph nodes lie?
Axillary fat
Where does the apical group of axillary lymph nodes lie?
Superior margin pectoralis minor
What does the humeral group of axillary lymph nodes drain?
Upper limb
What does the pectoral group of axillary lymph nodes drain?
Thorax
Mammary tissue
What does the subscapular group of axillary lymph nodes drain?
Back
Shoulder
Neck
What does the central group of axillary lymph nodes drain?
Communicates with other nodes
What does the apical group of axillary lymph nodes drain?
Mammary tissue
Other node groups
What do the grey rami communicantes that go to the brachial plexus roots carry?
Post-ganglionic SNS fibres
Where are the roots and trunks of the brachial plexus located?
Posterior triangle of neck
Pass between anterior and middle scalene muscles
What root(s) contribute to the superior trunk of the brachial plexus?
C5 and C6
What root(s) contribute to the middle trunk of the brachial plexus?
C7
What root(s) contribute to the inferior trunk of the brachial plexus?
C8 and T1
What is the route of the roots and trunks of the brachial plexus to enter the axilla?
Pass over rib 1
What do branches of the C5 root contribute to?
Phrenic nerve (C3-C5) -> Diaphragm Dorsal scapular nerve (C5) -> Rhomboids
What do branches of C5-C7 roots contribute to?
Long thoracic nerve (C5-C7) -> Serratus anterior
What do branches of the superior trunk only contribute to?
Suprascapular nerve (C5+C6) -> Infraspinatus Nerve to subclavius (C5+C6) -> Subclavius
In general terms, what do the 3 anterior divisions of each trunk of the brachial plexus supply and via what nerves?
Anterior compartments of arm and forearm
Via musculocutaneous and median nerves
In general terms, what do the 3 posterior divisions of each trunk of the brachial plexus supply and via what nerves?
Posterior compartments of arm and forearm
Via radial nerve
What are the peripheral branches of the divisions in the brachial plexus?
There are none
How are the cords of the brachial plexus named?
By their relation to the axillary artery
What divisions form the lateral cord?
Anterior divisions of superior and middle trunks
What are the roots values for the lateral cord?
C5-C7
What are the peripheral branch(es) of the lateral cord?
Lateral pectoral nerve (C5-C7)
What divisions form the posterior cord?
All posterior divisions
What are the root values for the posterior cord?
C5-T1
What are the peripheral branch(es) of the posterior cord?
Subscapular nerves (Upper and lower - C5+C6) Thoracodorsal nerve (C6-C8)
What divisions form the medial cord?
Continuation of the anterior division of inferior trunk
What are the root values for the medial cord?
C8+T1
What are the peripheral branch(es) of the medial cord?
Medial pectoral nerve (C8+T1)
Cutaneous nerves
What are the terminal nerve branches of the lateral cord?
(Lateral pectoral nerve)
Musculocutaneous nerve (C5-C7)
Lateral root of median nerve
What are the terminal nerve branches of the posterior cord?
(Subscapular nerves) (Thoracodorsal nerve) Axillary nerve (C5+C6) Radial nerve (C5-T1)
What are the terminal nerve branches of the medial cord?
(Medial pectoral nerve)
(Medial cutaneous nerves of arm and forearm)
Ulnar nerve (C8+T1)
Medial root of median nerve
What is the general function of the muscles in the anterior arm compartment?
Flexors of arm and elbow
What nerve supplies the anterior arm compartment?
Musculocutaneous nerve
What are the muscles of the anterior arm compartment?
Biceps brachii
Coracobrachialis
Brachialis
What are the origins of the biceps brachii?
Long head - Supraglenoid tubercle of scapula
Short head - Coracoid process
What are the insertions of the biceps brachii?
Radial tuberosity
Cubital fascia via bicipital aponeurosis
What are the functions of both heads of biceps brachii?
Supination
Flexion of elbow (when supine)
Weak flexion of arm
What is the function of the short head of biceps brachii?
Resists dislocation of shoulder
What is the function of the long head of biceps brachii?
Prevents head of humerus moving superiorly
What is the innervation to the biceps brachii?
Musculocutaneous nerve (C5+C6)
What is the origin of the coracobrachialis?
Coracoid process of scapula
What is the insertion of coracobrachialis?
Middle 1/3 of medial shaft of humerus
What are the functions of coracobrachialis?
Flexion of arm
Assists in adduction of arm
What pierces coracobrachialis?
Musculocutaneous nerve
What nerve innervates coracobrachialis?
Musculocutaneous nerve (C5-C7)
What is the origin of brachialis?
Distal half of anterior surface of humerus
What are the insertions of brachialis?
Ulnar tuberosity
Coronoid process of ulna
Where is brachialis found?
Deep to biceps brachii
What is the function of brachialis?
Flexes elbow (in all positions)
What is the innervation to brachialis?
Musculocutaneous nerve (C5+C6) Some lateral fibres from radial nerve (C7)
What are the origins of triceps brachii?
Long head - Infraglenoid tubercle of scapula
Lateral head - Post. surface humerus, sup. to radial groove
Medial head - Post. surface humerus, inf. to radial groove
What are the insertions of triceps brachii?
Proximal olecranon of ulna
Fascia of forearm
What are the functions of triceps brachii?
All parts - Extension of elbow
Long head - Resists dislocation of humerus (important in adduction)
What is the innervation to triceps brachii?
Radial nerve (C6-C8)
What is the most superior branch of the brachial artery?
Profunda brachii
What are the branches off of the medial aspect of the brachial artery?
Superior ulnar collateral
Inferior ulnar collateral
What does the profunda brachii artery branch into at the lateral aspect of the arm?
Middle collateral artery
Radial collateral artery
After the bifurcation of the brachial artery, what branch is given off of the radial artery?
Radial recurrent artery
After the bifurcation of the brachial artery, what are the branches off of the ulnar artery?
Anterior ulnar recurrent artery
Posterior ulnar recurrent artery
Common interosseous artery
What are the branches of the common interosseous artery?
Anterior interosseous Posterior interosseous (gives off interosseous recurrent)
What does the middle collateral artery anastomose with?
Interosseous recurrent
What does the superior ulnar collateral artery anastomose with?
Posterior ulnar recurrent
What does the inferior ulnar collateral artery anastomose with?
Anterior ulnar recurrent
What does the radial recurrent artery anastomose with?
Radial collateral
What does the lateral intermuscular septum extend from?
Greater tubercle of humerus
What does the lateral intermuscular septum run along?
Lateral supracondylar ridge to the lateral epicondyle
What perforates the lateral intermuscular septum?
Radial neve
Profunda brachii artery
What does the medial intermuscular septum extend from?
Lesser tubercle of humerus
What does the medial intermuscular septum run along?
Medial supracondylar ridge to the medial epicondyle
What perforates the medial intermuscular septum?
Ulnar nerve
(Superior ulnar collateral artery)
(Posterior branch of the inferior ulnar collateral artery)
What are the 3 parts of the medial collateral ligament?
Anterior
Posterior
Oblique
What does the medial collateral ligament of the elbow do?
Prevents abduction
How many bands does the lateral collateral ligament of the elbow have?
1
What does the lateral collateral ligament blend with?
Annular ligament
What does the lateral collateral ligament do?
Prevents adduction of the elbow
Where is the annular ligament?
Around neck of the radius
What does the annular ligament allow?
Pronation and supination
What bursae are present in the elbow joint?
Subcutaneous olecranon bursa
Subtendinous bursa of triceps brachii
What are the boundaries of the cubital fossa? (Lateral, medial, roof and floor)
Lateral = Brachioradialis Medial = Pronator teres Roof = Skin, fascia and bicipital aponeurosis Floor = Brachialis
Where do the superficial veins run in the cubital fossa?
In the superficial fascia above the bicipital aponeurosis
What are the contents of the cubital fossa from medial to lateral?
Median nerve
Bifurcation of brachial artery (into ulnar and radial)
Biceps tendon
Radial nerve
