Pectoral Region and Axilla
Go into detail about the anterior circumflex humeral artery: where it arises from, and what it supplies
-Anterolateral surface of axillary artery by the *surgical neck*, courses laterally to anastomose with the posterior counterpart -Always smaller than posterior counterpart
Go into detail about the posterior circumflex humeral artery: where it arises from, and what it supplies
-Anteromedial surface of axillary artery by the *surgical neck*, courses posteriorly with *axillary nerve* to anastomose with its anterior counterpart -Always smaller than posterior counterpart
Go into detail about the lateral thoracic artery: where it arises from, and what it supplies
-Arises behind tje pectoralis minor -Supplies the lateral intercostal spaces, serratus anterior, pectoralis major AND minor and the mammary gland
Go into detail about the thoracoacromial artery: where it arises from, what it divides into
-Arises below the pectoralis minor, courses medially and pierces the costocoracoid membrane. -Gives off 4 branches: acromial, clavicular, deltoid and pectoral regions
Go into detail about the supreme/highest/superior thoracic artery: where it arises from and what it supplies
-Arises from inferior surface of axillary artery -Supplies 1st and 2nd *anterior* intercostal space
Which veins are superficial on the arm?
-Cephalic vein: Runs on deltopectoral groove, lateral -Basilic vein: medial -Median cubital vein: venipuncture, sits on median cubital fossa
What structures can be found in the axilla?
-Connective tissue: Fat and axillary sheath -cords and branches of Brachial plexus -Axillary artery/vein and their branches/tributaries -Axillary lymph nodes -Proximal portions of long and short heads of bicep brachii m and coracobrachialis m. -Fat
What do the superficial lymphatics of the upper limb drain? What do they end up from a medial and lateral perspective?
-Drain subcutaneous structures -Hand: Drain the palm dorsally and -Follow major superficial *veins*, primarily the basilic vein(medial). End in the *lateral* group of axillary lymph nodes -Lateral collecting ducts follow the cephalic vein and end in the *apical group* of axillary lymph nodes
What do the deep lymphatics of the upper limb drain? Where do they end up?
-Drain the periosteum, joint capsules, tendons and some msucle -Parallel the course of major *arteries* , drain to lateral and central axillary lymph nodes
What is clavipectoral fascia? What are the parts of it?
-Fascia that envelops the subclavius and pectoralis minor muscles Costocoracoid membrane: upper portion of clavipectoral fascia (coracoid to ribs) -Suspensory ligament of the axilla: lower portion of clavipectoral fascia afters it sweeps from both sides of pec minor to more a single sheet which ends by fusing with axillary fascia at floor of axilla making it dome like
What forms the axillary vein?
-Formed by the basilic vein and brachial veins -Not formed by, but later joined by the cephalic vein; after it goes thru the clavipectoral fascia
What is the concern with lymphangitis or lymphadenitits?
-Getting into the L/R jugulovenous angle and infection becoming systemic
When does the subclavian artery become the axillary artery?
-Inferior to border of rib 1
Go into detail about the subscapular artery: where it arises from, and what it supplies
-Largest branch off axillary artery -Inferior surface of axilla, aklong lateral border of subscapulris muscle -Divides into the: 1)Circumflex scapular artery: Part of the triangular space, participates in the scapular anastamoses 2) Thoracodorsal artery: courses with thoracodorsal nerve to supply the latissimus dorsi
What are the borders and objects that run through the quadrangular space?
-Lateral: Humerus -Inferior: Teres major -Medial: Triceps long head -Superior: Teres minor -Posterior circumflex humeral a. -Axillary nerve
What are the borders and objects that run through the triangular interval?
-Lateral: Triceps lateral head -Medial: Triceps long head -Superior: Teres major -profunda brachii a -Radial n.
What are the borders and objects that run through the triangular space?
-Lateral: Triceps long head -Superior: Teres minor -Inferior: Teres major -Circumflex scapular a.
What occurs to the limbs if we remove the lymph nodes from someone effected with cancer?
-Lymph can't drain, the corresponding limb with become swollen (edematous)
Draw the upper limb lymph schematic
-On left side its the left subclavian lymph trunk and then the the L. jugular trunk, L. bronchomediastinal trunk into the thoracic duct and finally the L. jugulovenous angle
What is the axillary sheath and what do you find inside of it?
-Prevertebral cervical fascia - The 3 cords of the brachial plexus, and the axillary artery and vein.
What comes off the 1st division of the axillary artery? What does it supply?
-Superior thoracic a. (AKA supreme or highest thoracic artery) -Supplies blood to intercostal spaces 1 and 2
Describe the arterial supply of the breast
-medial mammary branches via perforating branches of internal thoracic and intercostals aa 2-4 -direct branches via lateral thoracic a. -lateral mammary branches via lateral cutaneous branches of posterior intercostal aa 2-4
What comes off the 3rd division of the axillary artery? What does it supply?
1)*Subscapular a.* -2 Branches: Circumflex scapular a. Thoracodorsal a.: Supply lats 2)Circumflex humeral aa. ( 2 distinct arteries) *Anterior*: Usually smaller, wraps around humerus *Posterior*: Usually larger Total of 3 arteries
What are the branches of the subclavian artery?
1)Off thryocervical trunk -Transverse cervical a. -Dorsal scapular a.(50% of time) -Suprascapular a. 2)Internal thoracic a. 3)Vertberal artery
What are the 5 nodes in the axilla?
1)Pectoral: On lateral edge of pectoralis minor and deep to pectoralis major 2) Lateral: Along medial border of humerus 3) Subscapular: At junctions of teres major with latisimus dorsi 4) Central: Located anterior to the tendon of the subscapularis deep to the pectoralis minor 5) Apical: Located close to the cervico-axillary canal superior to the pectoralis minor -Considered infraclavicular in location
What comes off the 2nd division of the axillary artery? What does it supply?
1)Thoracoacromial a.(Proximal) -Small branches to acromion process, clavicle, pectoral muscles, and deltoids 2)Lateral thoracic a.(Distal) -Blood to lateral thorax, and serratus anterior muscle
Describe the glandular structure of the breast
15-20 lobes composed of tubule-alveolar glands each lobe is pyramid shaped with apex pointing toward nipple each lobe is drained by a single lactiferous duct proximal to the duct expands to form a lactiferous sinus and storage extra milk
How are the divisions off the axillary arteries divided?
1: Above pec minor 2:Deep to pec minor 3:Below pec minor
How many axillary lymph nodes are there?
20-30 in number
Define the axilla:
A tetrahedral shaped space at the junction of the upper limb and thorax. Boundaries provide a passageway, via the *cervicoaxillary canal* for nerves from neck and vessels from thorax (via root of the neck) to enter upper limb
When does the axillary vein become the subclavian vein?
After it crosses the lateral border of the 1st rib
What are the limits (borders) of the axilla?
Apex: clavicle,superior scapula, 1st rib; *forms the cervicoaxillary canal* Base: axillary fascia Anterior wall: Pec major/minor and clavipectoral fascia Posterior wall: Scapula with associated musculature: Teres major, Lat. dorsi, subscapularis Medial wall: ribs 1-4 or 5 with associated intercostal musculature covered by serratus anterior m. Lateral boundary: Junction of anterior and posterior axillary wall at intertubercular sulcus/groove
What is peau d'orange?
French for skin of the orange. It describes the dimpling and thickening of the skin of the breast seen with breast cancer. Cause by tumor cells blocking lymphatics, lack leaving lymphedema
Describe the surface anatomy of the pectoral region
Includes: clavicle jugular (suprasternal notch) sternal angle median furrow diploid process infrasternal angle nipple anterior axillary fold deltopectoral groove deltopectoral triangle
When does the axillary artery become the brachial artery?
Inferior border of teres major
What is lymphangitis?
Inflammation of the lymphatic vessels as a result of a distal infection
DO NOT NEED TO KNOW WHAT THE ARTERIES SUPPLIES, I ADDED THEM IN THERE FOR COMPLETIONS SAKE. IN REALITY I DID IT BEFORE I GOT TO THAT PART OF LECTURE SO **** ME. OH WELL. NOW YOU KNOW
LISTEN UP
Describe the anatomy of the breast
Superolateral tail known as the axillary tail of breast (Spence tail) areola is in the middle with a nipple in the middle of it. This skin is darker and elevated due to areolar glands. small raised bumps are from sebaceous glands and rudimentary milk glands
What runs through the suprascapular notch?
Suprascapular nerve and artery -Army over, navy under
Image of cutaneous nerves of trunk
T1 should not be here- remember dermatomes and limb buds (there is no T1 in this area) -ventral rami of thoracic spinal nerves become intercostal nerves which have a lateral cutaneous branch and an anterior cutaneous from T2-11. There are also supraclavicular nerves (C3,C4)
What vertebral level is the sternal angle at?
T4-T5
T/F: All the veins in limbs have valves
True
T/F: The axillary vein accompanies the axillary artery along its entire length
True
T/F: A singular artery feeds the upper limb
True, it just simply changes its name as it courses
Where do breasts develop?
along the milk line extra nipples: supernumerary nipples can develop along this line
Where is the breast approximately located?
between T2-T6
What is the median furrow?
between sternal attachments of the pectoralis major muscles
What dives into the deltopectoral triangle?
cephalic vein
What pierces the costocoracoid membrane?
cephalic vein thoracoacromial artery lateral pectoral n
Describe the muscle fiber orientation for the pectoralis major and how it assists with actions
clavicular part: attaches highest on trunk and attach lowest on humerus Sternocostal part: run parallel to ground Abdominal part: attach lowest on trunk and attaches highest on on the humerus
Describe the supportive structure of the mammary gland
entire gland is surrounded by loosely organized connective tissue and rests upon deep fascia covering pec major and serratus anterior cooper's ligaments aka suspensory ligaments connect superficial to deep fascia smooth muscle layer is located in the nipple and areola for emptying lactiferous ducts
Describe the lymphatic drainage of the mammary gland
follows venous drainage but parallels lactiferous ducts even more closely drains from individual lobules, nipple, and areola to a subareolar plexus *75% drains to axillary lymph nodes* *25% drains to parasternal lymph nodes-bad b/c can't palpate these* some drainage may also go to other breast, supraclavicular, and superficial abdominal area
Describe the distribution of cutaneous aa. and n. to the trunk
for nn. Ventral rami of thoracic spinal nerves become intercostal nerves which have a *lateral cutaneous branch and an anterior cutaneous* branch. -Remember no T1 in trunk, found in arm -Supraclavicular nerves (C3,C4) do upper shoulder cutaneous innervtion for aa: -Posterior intercostal aa come off the aorta and have *lateral cutaneous branches* -Anterior intercostal aa come off the internal thoracic a. -There is also *anterior perforating branches* off the internal thoracic (mammary) which is important for breast blood supply
Is complete paralysis of pec major likely?
no because it has innervation from all the cord levels of the brachial plexus lateral pectoral n: C5, C6, C7 medial pectoral n: C8, T1
What is lymphadenitis?
swollen lymph nodes
What is the worse case scenario of breast cancer metastasis? (Where would you see it?)
the closer you get to the jugulovenous angle to worse the chances. if the supraclavicular nodes are swollen and painful, the cancerous cells are just about to enter the blood stream thru the right subclavian lymphatic trunk (lymph vessel) or the thoracic duct (lymph vessel) depending on which side of the body. once in blood supply can go: liver brain-batson's blood bone-batson's
Describe the venous drainage of the breast
venae comitantes of arterial supply: -medial mammary v drains to anterior intercostal v which drains into SVC -lateral thoracic veins drain into axillary vein -intercostal veins drains into azygous system which drains into SVC
