Pectoral Region Flashcards
What are the muscles of the pectoral region?
Pectoralis major
Pectoralis minor
Serratus anterior
Subclavius
What is the most superficial pectoral muscle?
Pectoralis major
Origin of pectoralis major
Clavicular head - anterior medial surface of
clavicle
Sternocostal head - anterior surface of sternum
- upper 6 costal cartilages
- aponeurosis of external
oblique muscles
Insertion of pectoralis major
Intertubercular sulcus of humerus
Innervation of pectoralis major
Median pectoral nerve C8-T1
Lateral pectoral nerve C5,C6,C7
Action of pectoralis major
ADucts arm
Medial rotation
Flexes arm at shoulder joint
Origin of pectoralis minor
3rd-5th ribs
Insertion of pectoralis minor
Coracoid process of scapula
Innervation of pectoralis minor
Medial pectoral nerve C8-T1
Action of pectoralis minor
Stabilises scapula - draws in anteroinferiorly against thoracic wall
How does pectoralis minor stabilise the scapula?
Draws in anteroinferiorly against thoracic wall
Location of the subclavius
Directly below the clavicle
Origin of subclavius
Junction of 1st rib + its costal cartilage
Insertion of subclavius
Interior middle 3rd of clavicle
Innervation of subclavius
Nerve to subclavius
Action of subclavius
Anchors + depresses clavicle
Origin of serratus anterior
As separate ‘slips’ from lateral aspect of ribs 1-8
Insertion of serratus anterior
Medial border of scapula
Innervation of serratus anterior
Long thoracic nerve C5,C6,C7
Action of serratus anterior
Protracts scapula
ABduction of shoulder >90 °
Holds scapula against ribcage
What is the axilla?
A pyramidal space at the junction of upper limbs + thorax
Borders of the axilla
Anterior - pectoralis major + minor
Posterior - scapularis
- teres major
- latissimus dorsi
Medial - serratus anterior + thoracic wall
Lateral- intertubercular sulcus
Apex - lateral border of 1st rib
- superior border of scapula
- posterior border of clavicle
Base - axillary fascia + skin
Contents of the axilla
Axillary artery + vein
Chords + branches of brachial plexus
Axillary lymph nodes
Coracobrachialis
Short head of biceps brachii
Intercostobrachial nerve T2
What are the 3 routes of leaving the axilla?
-inferiorly + laterally
- via the quadrangular space
- via the clavipectoral triangle
Where does the cephalic vein enter the axilla?
Clavipectoral triangle
Where do the medial and lateral pectoral nerve leave the axilla?
Clavipectoral triangle
What are the axillary lymph nodes?
APICAL
Anterior
Posterior
Infraclaviclar
Central
Apical
Lateral
Outline the drainage of the right axillary lymph nodes
Right subclavian trunk >
Right lymphatic duct >
Right venous angle
Outline the drainage of the left axillary lymph nodes
Left subclavian trunk >
Thoracic duct >
Left venous angle
Where does the axillary artery start and what does it come from?
At lateral border of 1st rib
Subclavian artery
What are the three parts of the axillary nerve and what are they in relation to?
Pectoralis minor
1st part - proximal to pectoralis minor
2nd part - posterior to pectoralis minor
3rd part - distal to pectoralis minor
How many branches do each part of the axillary artery have?
1st part - 1
2nd part - 2
3rd part - 3
Branch from the 1st part of the axillary artery
Superior thoracic artery
Branches from the 2nd part of the axillary artery
Thoracoacromial artery
Lateral thoracic artery
Branches from the 3rd part of the axillary artery
Subscapular artery
Anterior circumflex humeral artery
Posterior CHA
Where do the anterior and posterior circumflex humeral arteries branch from?
3rd part of the axillary artery
Where does the axillary artery end and what does it become?
Lower border of teres major
Brachial artery
What forms the axillary vein and where from?
Paired brachial veins + basilic vein
At lower border of teres major
What are the superficial veins of the upper limbs?
Mostly cephalic + basilic veins
What vein do you take most commonly use for venipuncture?
Medial cubital vein at cubital fossa
Where does the cephalic vein run?
Along the pre-axial border
Lateral
Where does the basilic vein run?
Along post axial border
Medial
