UE: shoulder, bones, axilla and brachial plexus Flashcards Preview

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Flashcards in UE: shoulder, bones, axilla and brachial plexus Deck (70):


shoulder girdle: scapula and clavicle 

upper extremity: humerus, radius and ulna, carpals, metacarpals, phalanges 



know theL 

glenoid cavity 

infraspinous and supraspinous and subscapular fossae 

scapular spine 

acromian process 

coracoid prorcess 

suprascapular notch 


Scapula pic 

be sure to understand for the unit ... look at it from Exam 1 material 



Describe the humerus parts 

Head: attaches to glenoid cavity of scapula --

greater tubercle and lesser tubercle...intertubercular groove-- biceps tendon

anatomical neck vs surgical neck 

detoid tuberosity- deltoid attaches 




Humerus pic 


tramau anatomical neck vs the surgical neck 

any trauma applied to the humerus will like fracture at the surgical neck intead of the anatomical because it is much thinner 


deltoid tuberosity

deltoid attaches here.... where deltoid inserts on the humerus and pulls on it 



capitulum (lateral) --> radium 

trochlea (medial) --> ulna 

epicondlyes (lateral and medial) 

coronoid fossa- anterior 

olecranon fossa-posterior 



should joints 

between clavicle and manubrium, only attachment between UE and axial skeleton 

stabilized by ligaments... not a ton of movement 



between acromion of scapula and clavicle 



ball and socket joint between head of humerus and glenoid cavity 

glenoid cavity is lined by catilaginous glenoid labrum-- joint is supported by ligaments, rotator cuff muscles, and bursae (both continuous and separated from joint capsule) 


flexion, extension, abduction, adduction, medial/lateral rotation, circumduction ..... 

glenoid labrum with cup shape that allows for the head of humerous to plug into something 


bones of the forearm 

radius and ulna 



lateral forearm bone, thumb side 

Head= capitulum 

radial tuberosity 

styloid process 



radial tuberosity 

bicep muscle will attach... movement of the radius are different than movement of the ulna....

radius is able to pivot

The proximal end the radius is small and the ulna is kind of big... at the distal end, the radius is large and the ulna is small... 



medial forearm bone, pinky side 

Trochlear notch 

olecranon process --> olecranon fossa 

coronoid process --> coronoid fossa 

syloid process (looks like a pen)... these ends are where the wrist joint is going to form between the carpals and distal radius 


interosseous membrane 

ligament that hold the radius and ulna together in between... helps to divide them into anterior and posterior muscle 


pivoting of the forearm 

pivoting around the elbow... allows for flexion & extension and pronation & supination 

radius is not locked in place so it can pivot 

radius freely rotate along the capitulum (pivot joint) to allow for the frearm pronation and supination... in the pronated position the ulna and radius are crossed

radius and ulna attached to each other at distal and proximal ends 


3 joints of the elbow 

  1.  TRochlear notch of ulna and trochlea of humerus 
  2. head of radius and capitulum of humerus 
  3. head of radius and radial notch of the ulna 


what joint allows for supination/pronation (pivot)

proximal radio-ulna joint 

so head of radium and radial notch of the ulna 


what joints all for flexion and extension? 

trachlear notch of ulna and trohclea of humerus 

head of radius and capitulum of humerus   


anular ligament 

ligaments that support the elbow joint that wraps around the radial head 


describe the hand bones 

Carpals: (scaphoid, lunate, triquetrum, pisiform) *trapezium, trapezoid, capitate, hamate 

metacarpals (5 on each hand 

Phalanges: proximal, middle, distal (except thumb-proximal and distal only



Carpal arch 

capals form an arch... covered by the flexor retinaculum... tissue makes the carpal tunnel 


carpal bones arrangement 

Thumb side — scaphoid, lunate, triquetrum and pisiform 
    (piriformis is a sesamoind bone = a bone embedded in a tendon...not attached to other bone ... wrapped about a tendon)
Next row... trapezium, trapezoid, capitate, and hamate 
    Hamate has a hook 
    TRapezium is for the thumb.. forms the attachment between the carpals and the metacarpals of the thumbs... special joint= saddle joints... make opposable thumbs 

Some lovers try position that they can't handle 


Wrist joints and joints in the hand 

  • wrist joints (radius and ulna-- with articular disc- wiht scaphoid, lunate and triquetrum of the carpals 
  • capals joints; carpal have joints between themselves 
  • carpometacarpal joints-- the saddle joint between the first metacarpals and the trapezium allow for special movement of the thumb 
  • metacarpophalangeal joint (MCP)-- betwen metacarpals and proximal phalanges 
  • interphalangeal joints: proximal (PIP) and distal (DIP)


back muscle 

  • Latissimus dorsi: originated on the spine and inserted onto the front of humerus... adduction, extension and medial rotation 
  • Trapezius:  originate on the spine and the head and inserted on the side of the shouldner on the spine of acromin...move shoulder up and down and retraction of scapula
  • Rhomboid major and minor: retract scapula 
  • Pectoralis major and minor: starts on the sternum and inserts on the front of the humerous, does adduction and medial rotion and flexion 
  • serratus anterior: protraction 



triangular muscle from scapula and clavicle to humerus at the deltoid tuberosity 

action: arm abduction (beyond supraspinatus motion)

innervation: axillary nerve 

But can’t initiate abduction... it can’t do the first 15 degrees, it has to be helped first (by the supraspinatus) and then does the rest of abduction 

Ex. Flu shot in the deltoid... if you feel sore when you continue to abduct past 15  degree and then deltoid takes over for the rest of it 


Which one doens’t get innervation from the brachial plexus?

The trapezius is innervated by a spinal accessory nerve...cranial nerve that come from the head  


what are the muscles over the scapula 

  1. infraspinatus
    • originates on the infraspinatus fossa and inserts on the humerus 
    • allows humerus to rotate laterally 
    • innervation is from the suprascapular nerve off the bracial plexus 
  2. supraspinatus 
    • originates on the supraspinatus fossa and inserts on the humerus 
    • abducts the humerus--does the first 15 degrees 
    • innervation is from the suprascapular nerve off the bracial plexus 



muscles over the scapula 

posterior side: teres major and minor 

minor superior to major 

action: minor= lateral rotation fo the arm 

major= same as lat dorsi, same insertion....medial rotation, extension, adduction 


minor: axi


teres major 

action: same as lat dorsi.. same inserton

-medial rotation, extension, adduction

innervation: lower subscapular nerve 


origin is is the infraspinatus fossa but insertion front of humerus...allows adduction. medial rotatio nand extension 


teres minor 

next to infrapinatus

minor: lateral rotation of the arm 

innervation: axillary nerve 


muscle over the scapula: subscapularis 

in the subscapular fossa on the anterior side of the scapula 

medial rotation of the arm 

innervated by the subscapular nerve 



Latissimus dorsi 

between the two majors: between the pec major and teres major.....the la-di between the two majors 


muscles associated with the scapula 


stars mean it's part of the rotator cup muscle...


Blood supply to the axilla 

axillary artery comes from the subclavan artery.. up through thoracic inlet over rib 1,

curve around rib 1 under the clavical and go into axilla and change name to the axillary artery 

Axillary vein becomes subclavian vein goin in the opposite direction


important structures that pass from the neck to the upper extremety 

bracial plexus here comes from the neck and goes through the opening of the axilla and go down to the upper limb and innervates all the muscles that are in the upper limb and move the upper limb and the muscles in the back 


Brachial pl


describe the axilla boundaries 


anterior wall 

medial wall 

lateral wall 

posterior wall 



describe the inlet of the axilla boundaries 

defined by bone 

clavicle- anterior 


rib 1- medial 


describe the anterior wall of the axilla boundaries 

clavipectoral fascia (subclavious and pectoralis minor) 

pectoralis major 


describe the medial wall of the axilla boundaries 

toracic wall and serratus anterior 

ribs and the serrated muscle 


describe the later wall of the of the axilla boundaries 



describe the posterior wall of the axilla boundaries 

muscle over the scapula and triceps muscle 


describe the floor of the axilla boundaries 

lateral to the floor the axilla is continuous with the anterior compartment of the arm 


overall picture of the axilla boundary 


axillary artery 

  • the right subclavial artery passes under the clavical and lateral to rib 1==> becomes axillary artery 


tell me about the divisions of the axillary arteyr 

  1. proximal to pectoralis minor 
    • superior thoracic 
  2. posteiror to pec minor 
    • thoraco-acromial 
    • lateral thoracic 
  3. distal to pec minor 
    • subscapular 
    • anterior and posteral cicumflex humeral (go around humerous and meet in the middle) 

the axillary artery continues as the brachial artery in the arm 


the brachial artery 

as the axillary artery passes the borader of teres major, it becomes the brachial arty.....travels down the front of the arm...anterir compartment near the elbow it divides into the radial and ulna arteries  

has to give a branch to supply the back of the arm (profunda brachii) which supplies the posterior arm... runs with the radial nerve 

used for blood pressure measurements 


note that the branches of the bracial artery suppy the elbow in addition to other branches 


axillary viens 

axillary vein accompanies the axillary artery and becomes subclavian vein after passing rib 1 -- deep veins are the bracial vein that accompany the brachial artery--


Cephalic vein drains posterior later side of UE and passes in the deltopectoral groove between the deltoid and pectoralis major muscle before it enter the axillary vein 

small brachial veins accompany brachial arty, but superfical structures are drained by cephalic (lateral) and basilic (medial veins) 

veins originate near the hand and travel up the forearm.. cephalic vein and basilic vein make up most of the axillary artery 


axillary nodes 

present in the axilla region... have many different groups that drain different things... 

Drains the UE and parts of the upper back, shoulders, neck and most of breast 

divided into groups based on location in the axilla 

all drain up to the top of the axilla and drain up to the neck... all lymph ends up at the junction subclavian and internal jugular 



Bracial Plexus 

complex collection of nerves from the spinal cord traveling through the neck and axilla to innervate muscles and skin in the UE... formed from anterior (ventral) rami of C5-T1 spnal segments 

divides ito prximal to distal: 






brachial plexus... more info  just read 

comes from cervical outflow.. C5-T1 ... starts in the neck and travels to the upper limbs into the axillary inlet between the clavical and scapula and the first rib and then go through the axilla and then through the axilla and then it's going to branc and give different branches that are going to supply all the muscle in the upper limb that move the upper limb in the upper limb but also on the chest wall and that in the upper back expect for trapezius which gets the spinal accessory nerve 


Brachial plexus.. cords and roots 

roots: C5 -T1.. exit from the spinal cord and contributes to the brachial plexus or anterir rami of the 5 outflow segmens that make the roots... 

trunk: superior, middle, inferior ... passes from neck to axilla 

division: anterior and posterior ... post (supply the posterior compartments), ant (medial and lateral cords)

cords: lateral, posterior, medial 

most major nerves of the UE branch off the cords  


Nerves of the brachial plexus 

Nerves off the roots= dorsal scapular and long thoracic 

nerve off of the trunks= supracscapular and nerve to subclavious 

tthere are no nerves off the divisions 


long thoracic nerve 

off the roots... from multples of these and travels on the throacic wall and innervates serratus anterior 


dorsal scapular 

nerve off the roots 

innervates the rhombids 


nerve to subclavious 

under clavical...


suprascapular nerve 

no direct branches from the division 

in trunk have inforior and superior ... which does anterior side of scapula and the lower one does the terese major 


lateral cord 

lateral pectoral nerve that innervates the pectoralis major...from the lateral cord we have the terminal nerve so the musculocutanous cord comes from the lateral cord 

lateral cord contributes to 1/2 of the innervation to the median nerve 


medial cord 

has medial pectoral nerve... innervate pec major and minor 

has 2 cutaneous nerve (sensory for skin) ... medial cutaneous of the arm and medial cutaneous of the forearm .. medial side of arm and foreamr contributes the ulna nerve and 1/2 median nerve 


posterior cord 

gives axillary nerve to innervate the deltoid and teres minor so the axillary nerve is going to travel to the back of the scapula where teres minor is located and then we have tthe thoracordosl never to innervate the lats in the back 



nerves off of the cords 

  • lateral:
    • lateral pectoral 
    • musculocutaneous 
    • median 
  • posterior 
    • thoracodorsal 
    • superior and inferior subscapular 
    • axillary
    • radial 
  • ​Medial 
    • median 
    • medial pectoral 
    • medial cutaneous nerves ofthe arm and forearm 
    • ulnar  





identifying the braches 

axillary runs between the anterior and poseterior division of the brachial plexus 

Find the M of the bracial plexus 

from lateral to medial: 

Musculocutanous, median , ulna 

posterior cord behind axillary artery... radial nerve 


cutaneous innervation of the upper limb