Clinical Anatomy Of The Axilla & Brachial Plexus Flashcards
What is the axilla?
A pyramid-shaped space between. Between upper arm and thorax
Axillary inlet (apex, cervicoaxillary canal) -clavicle, coracoid process and superior margin of scapula, 1st rib
What are the 4 walls of the axilla?
Anterior
Posterior
Medial
Lateral
Also has floor
What constitutes the walls and floor of the axilla?
- Anterior (anterior fold)= pectoralis major and minor
- Posterior (posterior fold)= teres major, latissimus dorsi subscapularis
- Medial= serratus anterior, ribs, etc.
- Lateral= Intertubercular (bicipital) groove of humerus
Floor= axillary fascia
What is the function abs innervation of the serratus anterior?
Long thoracic nerve (C5,6,7)
Rotates scapula upward to allow lifting arm above 90 degrees
-protracted the scapula to keep the medial border against the thoracic wall
Clinical correlate: winged scapula
What are the muscles of the anterior wall? What are the functions of the muscles?
Pectoralis major-medial and lateral pectoral nerves
Flexion, adduction and medial rotation of the arm
Pectoralis minor- medial pectoral nerve, pulls tip of shoulder down
What are the muscles of the posterior wall? W(at are there functions?
Subscapularis- upper and lower subscapular nerves. Medial rotation of the arm
Teres major- lower subscapular nerve. Medial rotation, adduction, extension of the arm
Latissimus dorsi- thoracodorsal nerve. Medial rotation, adduction, extension of the arm
What are the brachial plexus chords?
Lateral, posterior, medial
What are the components of the posterior scapular spaces?
Triangular space:
-circumflex scapular artery
Quadrangular space:
-axillary nerve
-Posterior humeral circumflex artery
Triangular interval
-radial nerve
-deep brachial artery
What is the Subclavian artery?
Divided into three parts by the anterior scalene muscle. Most branches from the first division:
1st part (medial to scalene )
- Vertebral
- Internal thoracic
- Thyrocervical trunk
- transverse cervical
- deep
- superficial
- transverse cervical
- suprascapular
- inferior thyroid
2nd part (behind the scalene) -costocervical
3rd part (lateral to scalene) -dorsal scapular if present
Which blood vessel curves over the 1st rib?
Distal part of the Subclavian artery as it curves over 1st rib to become the axillary artery
What is the axillary artery?
Continuation of Subclavian artery
Begins at lateral border 1st rib
Ends at inferior margin of teres major
Divided into 3 parts by pectoralis minor:
- proximal
- posterior
- distal
What are the parts of the axilllary artery?
1st part -proximal: superior thoracic
2nd part- posterior
- thoraco-acromial
- acromial(A)
- pectoral(P)
- clavicular(C)
- deltoid(D)
- lateral thoracic
3rd part-distal
- subscapular
- Thoracodorsal
- circumflex scapular
- Posterior circumflex humeral
- Anterior circumflex humeral
What are the parts of the scapular anastomosis?
Dorsal scapular or deep branch of transverse cervical artery
Suprascapular artery
Circumflex scapular artery
What is the dorsal scapular/ deep branch of transverse cervical artery ?
Which is a branch of thyrocervical trunk from Subclavian
What is the suprascapular artery?
A branch of thyrocervical trunk from Subclavian
What is the circumflex artery?
Branch of subscapular artery which is from 3rd Parathion of axillary
What is the axillary vein formed by?
- basilic vein and paired brachial veins
- begins at inferior margin of teres major
- ends at lateral border 1st rib
- receives the cephalic
What is the axillary sheath?
- surrounds arteries, veins, nerves and lymphatic
- can be used for brachial plexus blocks
What are the axillary vein purpose ?
The axillary vein is used as an entrance to the Subclavian vein for the insertion of “Subclavian” venous catheter
What is the somatic plexus?
Thoracic ventral rami. Innervating the trunk remain separate from each other
Ventral rami innervating the limbs merge with adjacent rami to form somatic plexuses: nerve fibers from adjacent rami intermingle
Named nerves arise from plexus and contain fibers from two or more rami
What are Apical nodes?
Most superior nodes
Receive lymph from all other axillary nodes and superficial lymphatics from lateral upper limb accompanying cephalic vein
What are central nodes?
Receive lymph from anterior, lateral and posterior groups
What are the lateral nodes(humeral)?
Receive lymph from the medial aspect of the upper limb accompanying the basilic vein
What are posterior nodes(scapular)
Receive lymph from posterior thoracic wall, back and posterior shoulder
What are anterior nodes (pectoral)?
Receive lymph from anterior and lateral thoracic wall and breast
