Pectoral Region Flashcards
The skin of the pectoral region innervated by?
Branches of the supraclavicular nerve and the ventral rami of the intercostal nerves
Pectoral fascia
- Superior attachment ?
- Inferior/lateral attachment?
- Division?
- What does it form and where?
- Sternum and clavicle
- Continuous with fascia of the shoulder, axilla, and thorax
- Anterior and posterior: attach to spinous processes of thoracic vertebrae
- Forms the axillary fascia at the axillary space when closing interval between pec major and lats
Clavipectoral fascia:
Structures that pierce it and what direction
Outwards: lateral pectoral nerve and thoraco-acromial artery
Inwards: cephalic vein and lymphatics (from breast to apical group of axillary group of lymph nodes)
Clavipectoral fascia
- This fascia is deep to ____
- It occupies the space between ___ and ___
- The clavicular head of the pectoralis major muscle
2. The clavicle and pectoralis minor
Clavipectoral fascia:
It runs vertically from ___ to ____; its upper part splits into 2 laminae to enclose what muscle?
Clavicle above to axillary fascia below; subclavius muscle
Clavipectoral fascia
What ligament maintains the concavity of the axilla?
Suspensory ligament
Where is clavipectoral fascia connected medially?
Laterally?
Where does the costocoracoid ligament run between?
Medially: first rib and costoclavicular ligament
Laterally: coracoid process and blends with the coracoclavicular ligament
Thick upper part of the fascia extending from the first rib near costochondral junction to coracoid process
What muscles are enclosed within the clavipectoral fascia?
Pectoralis minor and subclavius
4 muscles of the pectoral region
Pectoralis major and minor, subclavius and serratus anterior
Pectoralis major
Origin Insertion Innervation Action Arterial supply
Origin: clavicular head- front of the medial 1/3 of clavicle; sternocostal head- anterior aspect of sternum/upper 6 costal cartilages
Insertion: lateral lip of bicipital groove of humerus
Innervation: lateral pectoral nerve (C5-C7) and medial pectoral nerve (C8-T1)
Action: adduction and medial rotation of the arm; flexion of the arm (clavicular portion)
Arterial: pectoral branch of the thoracoacromial trunk
3 branches of the medial cord of the brachial plexus
Medial pectoral nerve, medial cutaneous nerve of arm and medial cutaneous nerve of forearm
Pectoralis minor
Origin Insertion Innervation Action Arterial
Origin: ribs 3-5 near their cartilage
Insertion: medial aspect of coracoid process
Innervation: medial pectoral nerve (C8-T1)
Action: depresses point of shoulder, elevates the ribs of origin (when the scapula is fixed)
Arterial: pectoral branch of the thoracoacromial trunk
Subclavius
Origin
Insertion
Innervation
Action
Origin: first costal cartilage
Insertion: lower surface of clavicle (subclavius groove)
Innervation: nerve to the subclavius (C5-C6)
Action: depresses the clavicle, stabilizes the clavicle during movements of the shoulder girdle
Serratus anterior
Origin Insertion Innervation Action Arterial
Origin: outer surface of upper 8 ribs (medial)
Insertion: medial border of scapula/ inferior angle of scapula
Innervation: long thoracic nerve (C5-C7)
Action: protraction and rotation of the scapula
Arterial: lateral thoracic artery
What type of gland is the mammary gland?
Where is your nipple located
Apocrine (large sweat gland that produces fluid)
4th intercostal space
5 arteries of the mammary gland
Internal thoracic artery Lateral thoracic artery Superior thoracic artery Acromio-thoracic artery Lateral branches of posterior intercostal artery
Veins follow the arteries in their course and adopt their names
These veins form an anastomotic venous circle around the nipple that divides into:
Superficial anastomosis veins: drain into ?
Deep venous anastomosis: drain into?
Superficial drains into internal thoracic and superficial veins of lower neck
Deep drains into internal thoracic, axillary, and posterior intercostal veins
Lymphatic drainage
- What are the 5 AXILLARY nodes? (Just the name)
- Which is the only one that doesn’t drain lymph and what does it do instead?
1. Anterior (pectoral) group Posterior (subscapular) group Lateral group Central group Apical group
- Central group receives lymph from the anterior, posterior, and lateral groups of lymph nodes
lymphatic drainage
- Where is anterior group located and what does it drain?
- Where is posterior group located and what does it drain?
- Where is lateral group located and what does it drain?
- Where is central group located and and where does it RECEIVE lymph from?
- Where is apical group located and what does it drain and what does it receive
- Lower border of pec minor (along lateral thoracic vessels) and drains outer quadrant of the breast
- Posterior wall of axilla along the lower border of the subscapularis. Drains lower outer quadrant of the breast
- Over the lateral wall of axilla besides the humerus and drains a minimal quantity of lymph from the breast
- In the base of the axilla and it receives lymph from anterior, posterior, and lateral groups of lymph nodes
- Deep in the apex of the axilla. Drains the upper medial quadrant and receives lymph from all the above groups.
Lymphatic drainage
- Internal mammary (parasternal) nodes are located where?
- What do they drain?
- Clinical: What is the route that metastasis would take
- Beside the lateral border of the sternum surrounding the internal mammary artery
- Drain the medial quadrants of the breast
- Cross to the other side and drain to the opposite group of parasternal nodes (would spread disease from one breast to the other)
- Axillary and parasternal are the two main nodes for lymphatic drainage of the breast, but name 3 others.
- Name two lymph plexuses of the breast.
- How would disease metastasis from breast to abdomen?
- Supraclavicular nodes, cephalic (deltopectoral) nodes, and posterior intercostal nodes
- Subdiaphragmatic and subperiotoneal lymph plexuses
- Through subdiaphragmatic and subperiotoneal lymph plexuses
- The skin drains into what 3 nodes?
2. The areola and nipple drain to ?
- Axillary, inferior deep cervical, and infraclavicular nodes
- Subareolar lymphatic plexus
- Nerve supply of the breast?
2. Innervation of the upper and lower portion of the breast?
- 4th to 6th intercostal nerves from anterior cutaneous branch and lateral cutaneous branch
- Suprascapular nerve
What does supernumerary mean?
Where does this occasionally occur?
It means there is breast tissue growing somewhere it shouldn’t be
Can occasionally occur along a line extending from the axilla to the groin
