lecture 8 - axilla brachial plexus Flashcards
axilla walls - apex
“armpit”
axilla walls - base
formed by skin
anterior wall of the axilla walls?
pectoralis major and minor
what forms the lateral wall of the axilla walls?
pectoralis minor and major
what forms the medial wall of the axilla walls?
serratus anterior and rib cage [4th rib]
what forms the posterior wall of the axilla walls?
lat dorsi, subscapularis, teres major
what are the roots of the brachial plexus?
anterior rami of…
-c5
-c6
-c7
-c8
-t1
R T D C B
R- rami
T -trunk
D - division
C - cords
B- branches
trunk sections..
superior, middle, inferior
divisions sections…
3 anterior and 3 posterior
cords sections…
lateral, posterior, medial
branches sections…
5 peripheral nerves
subclavius MA
- depresses and anchors clavicle
subclavius PA
junction of first rib and its costal cartilage
subclavius DA
inferior surface of middle surface of clavicle
subclavius nerve
subclavian nerve [c5.c6] nerve to subclavius
anterior scalene nerve
cervical spinal nerve c4 to c6
anterior scalene MA
- flex neck laterally
- elevates first rib during forced inhalation
middle scalene MA
- flex neck laterally
- elevates first rib during forced inhalation
what are the IA for the anterior and middle scalenes?
first ribs!
middle scalene nerve
anterior rami of cervical spinal nerves
posterior scalene MA
flex neck laterally
elevated SECOND rib during forced inhalation
posterior scalene IA
external border of 2nd rib
what is thoracic outlet syndrome?
compression of nerves, arteries, and veins in thoracic outlet
how does thoracic outlet occur?
occurs via compression in space between the clavicle and 1st rib, pec minor, or the presence of a cervical rib
quadrangular space
an anatomical conduit for neurovascular structures to pass from anterior axillary region to posterior scapular region
quadrangular space - inferior margin
teres minor
quadrangular space - superior margin
teres major
quadrangular space - lateral margin
long head of the triceps brachii
quadrangular space - contents
- posterior circumflex humeral artery and vein
- axillary nerve
triangular space margins
medial margin:
superior margin:
inferior margin:
medial margin: long head of biceps brachii
superior margin: teres major
inferior margin: teres minor
triangular space contents
circumflex scapular artery and vein
triangular interval
margins
lateral margins:
inferior margin
lateral margin: long head of triceps brachii & shaft of humerus
inferior margin: teres major
triangular interval contents
profunda brachii artery & radial nerve
what is the only synovial joint articulation between UE and axial skeleton?
sternoclavicular joint
what are the 3 muscles of the flexor compartment?
BBC
B - brachialis
B - iceps brachii
C - coracobrachialis
main blood supply of UE?
brachial artery
what is the main action of the biceps brachii?
supination of the arm
Biceps brachii MA
- *supination of the arm
- flexes forearm
- short head resists dislocation of shoulder
biceps brachii PA
- Short head: coracoid process
- Long head: supraglenoid tubercle & labrum
biceps brachii DA
radial tuberosity and fascia of forearm via bicipital aponeurosis
biceps brachii nerve
musculocutaneous nerve (c5,c6*,c7)
what muscles attach to the coracoid process?
coracoid brachialis
biceps brachii short head
pectoralis minor
coracobrachialis MA
- flexes scapula
- adduct shoulder
- resists dislocation of shoulder
coracobrachialis PA
coracoid process
coracobrachialis DA
middle third of medial surface of humerus
coracobrachialis nerve
musculocutaneous nerve c5,c6*,c7
who is the skrongest flexor of the elbow
brachialis
brachialis MA
flexes elbow in all positions - humorolnar joint
brachialis PA
distal half of anterior surface of humerus
brachialis DA
ulnar tuberosity and coronoid process of ulna
brachialis nerves
- musculocutaneous nerve (C5 & c6) & small branch from radial (c5 & c7)
Triceps brachii MA
chief extensor of forearm/elbow
long head resists dislocation of humerus, especially during adduction
Triceps brachii PA
long head: infraglenoid tubercle
lateral head: posterior humerus, superior to radial groove
medial head: posterior humerus, inferior to radial groove
Triceps brachii DA
olecranon of ulna
Triceps brachii nerve
radial nerve (c6,c7,c8)
what nerve supplies the entire posterior compartment?
radial nerve
deep radial nerve changes name to…
posterior interosseous nerve [PIN]
radial nerve levels
c5.c6.c7.c8.t1
musculocutaneous level
c5.c6.c7
axillary nerve levels
c5.c6
