Pectoral Region & Axilla Flashcards
The pectoral girdle (clavicles and scapulae) is connected anteriorly to the…
manubrium of the sternum
Components of the sternum
manubrium (juglar notch, clavicular notch, sternal angle)
Body
xiphoid process
Landmarks of the clavicle
acromial end (lateral, articulates w/ acromion process of scapula)
sternal end (medial)
trapezoid line and concord tubercle (lateral)
groove for subclavius m.
impression for costoclavicular ligament (anchor to 1st rib)
Landmarks of the scapula
coracoid process (thumb) acromion process glenoid fossa (head of humerus) suprascapular notch sub scapular fossa (ant., attach for subscapularis m.) supraspinous fossa (post.) infraspinous fossa (post.) spine of scapula (post.)
clavicle articulates w/ axial skeleton via
sternoclavicular joint
clavicle articulates with scapula via
acromioclavicular joint
coracoclavicular joint
scapulothoracic joint
a physiological joint
- scapula overlying the posterior thoracic wall
- movement occurs in all directions
humerus is connected to pectoral girdle by the
glenohumeral joint
- a ball and socket joint
subacromial space and scapulothoracic joint are
physiological (functional) joints
which ligament reinforces the clavicle laterally
acromioclavicular ligament
coracoacromial ligament
between coracoid process (ant) and acromion process (post)
Ligaments of the pectoral girdle region
acromioclavicular ligament
coracoacromial ligament
coracoclavicular ligament
sternoclavicular ligament
costoclavicular ligament
function and components of the coracoclavicular ligament
stabilizes lateral end of clavicle
2 ligaments: trapezoid and conoid
which ligament anchors medial end of clavicle to manuibrium
sternoclavicular ligament
which ligament anchors medial end of clavicle to 1st rib
costoclavicular ligament
Piano-key sign
via fall on shoulder or outstretched hand
- humerus displaces lateral end of clavicle
- injury to ACROMIOCLAVICULAR ligament and/or CORACOCLAVICULAR ligament
- lat end of clavicle is elevated away from rest of scapula
Clavicle fracture
via fall on outstretched hand/directly on shoulder/high impact accident (car/bike)
- comm frac site: btw lateral and middle thirds
- immobilized w/ sling, surgery if bones are fragmented
4 anterior axioappendicular m. of pectoral region
pectoralis major m
pectoralis minor m
serratus anterior m
subclavius m
medial border of deltopectoral triangle
pectorals major m
which vein ascends up lateral upper extremity from forearm, along deltopectoral groove
cephalic vein
which vein ascends up medial side of upper arm
basilic vein (becomes axillary vein)
boundaries of the axilla
pectoralis maj. and min. (ant.)
serratus anterior (med.)
subscapularis, teres major and latissimus dorsi (post.)
inter tubercular groove (lat.)
axillary skin fold (base)
apex (btwn clavicle, 1st rib, and scapula)
contents of the axilla
lymphatics
axillary artery
axillary vein
brachial plexus
pathway of pectoral and axillary lymphatics
pectoral, sub scapular, and humeral nodes –> central nodes –> apical nodes –> venous system via R lymphatic duct (R side) and thoracic duct (L side)
Most common site of metastasis from breast cancer
axillary nodes (pectoral, subscapular, apical, central, and humeral)
Heart –> R brachial a. (path)
heart –> aorta –> bracocephalic a. –> R. subclavian a. –> R. axillary a. (as it passes 1st rib) –> R. brachial a. (as it passes border of teres major)
Borders of 3 parts of the axillary artery
1st part: btwn lat border of 1st rib and superior border of pectoralis minor
2nd part: deep to pectoralis minor
3rd part: between inferior border of pectoralis minor and inferior border of teres major
Branches of axillary artery
1st part –> 1 branch –> superior thoracic a.
2nd part –> 2 branches –> thoracoacromial trunk, lateral thoracic artery
3rd part –> 3 branches –> subscapular a., ant. circumflex humeral a., post. circumflex humeral a.
thoracoacromial trunk branches
(branches off 2nd pt axillary a.) acromial a. clavicular a. pectoral a. deltoid a.
Atlantic City Police Dept.
vein that connects cephalic and basilic veins
median cubital v.
site for venipuncture
vein that drains up lateral side of arm into deltopectoral groove
cephalic v.
vein that dives deep w/i arm (1/2 way up, medial) and drains deep veins to become axillary v.
basilic v.
any plexus found in body is made up of
ventral primary rami
brachial plexus
ventral primary rami of C5, 6, 7, 8 and T1 spinal n. –> combine as trunks –> divisions –> combine as cords –> divide into 5 terminal branches
Brachial plexus carries _______________ info to the entire upper limb
motor AND sensory
ventral primary rami
trunks of brachial plexus
(combo of roots/rami)
upper trunk= C5 + C6
middle trunk= C7
lower trunk= C8 +T1
divisions of brachial plexus
sep of each trunk into ant and post divisions
divide posterior to clavicle
cords of brachial plexus
*named relative to axillary a.
lateral cord (via ant. divisions of upper and middle trunks)
medial cord (via anterior division of lower trunk)
posterior cord (via all 3 posteror divisions)
branches of brachial plexus
5 terminal branches from cords
lateral cord –> musclocutaneous n. and lat root of median n.
posterior cord –> axillary n. and radial n.
medial cord –> ulnar n. and medial root of median n.
Supraclavicular branches
branches from roots or trunchs, pts of brachial plexus ABOVE CLAVICLE
Roots
- dorsal scapular n. (C5)
- long thoracic n. (C5, 6, 7)
Trunks
- supra scapular n. (C5, 6)
- n. to subclavius (C5, 6)
Infraclavicular branches
branches from cords BELOW CLAVICLE
Lateral cord
- lateral pectoral n. (C5-7)
Medial cord
- medial brachial cutaneous n. (C8, T1)
- medial pectoral n. (C8, T1)
- medial antebrachial cutaneous n. (C8, T1)
Posterior cord
- upper sub scapular n. (C5)
- thoracodorsal n. (C6-8) (aka middle subscapular n.)
- lower subscapular n. (C6)
long thoracic n. supplies…
serratus anterior
dorsal scapular n. supplies…
rhomboid major
rhomboid minor
levator scapulae
supra scapular n. supplies…
supraspinatus m.
infraspinatus m.
winged scapula
injury to long thoracic n. (travels SUPERFICIAL to serratus anterior m)
- medial border and inferior angle of scapula pull away from posterior thoracic wall
- notable when person presses hand against wall
medial and lateral pectoral n.
supplies pectoralis major
medial pectoral n.
supplies pectoralis minor
upper subscapular n.
supplies superior pt of subscapularis m.
lower subscapular n.
supplies
- inferior part of subscapularis m.
- teres major m.
thoracodorsal n.
latissimus dorsi m.
medial brachial cutaneous n.
medial arm
medial antebrachial cutaneous n.
medial forearm
musculocutaneous n.
all ant arm muscles (brachial, coracobrachialis, biceps brachii)
continues on as lateral antebrachial cutaneous n.
median n.
- anterior forearm EXCEPT flexor carpi ulnari and medial half flexor digitorum profundus
- 5 intrinsic muscles of hand
ulnar n.
- 2 muscles of anterior forearm (flexor carpi ulnas and medial half flexor
- most intrinsic muscles of hand
radial n.
all muscles of posterior arm (triceps) and forearm
axillary n.
deltoid and teres minor m.
location of musculocutaneous n.
typically pierces coracobrachialis m. and runs between coracobrachialis, brachial, and biceps brachii m.
emerges deep from biceps brachialis just lateral to biceps tendon as LATERAL ANTEBRACHIAL CUTANEOUS N.
continues down forearm (provides sensation to lat forearm)
