Pectoral Region and Axilla Flashcards
median furrow
between sternal attachments of pectoralis major muscle
sternal angle
between manubrium and sternum
**junction of second rib
nipple
male/pre-pubertal female
-at point of junction with second rib
anterior axillary fold
lateral border of pectoralis major
deltopectoral triangle
junction of:
clavicle
deltoid
pectoralis major
deltopectoral groove
between deltoid and pectoralis major
-cephalic vein location
supraclavicular nerves
C3 and C4 from cervical plexus
-superficial structure
anterior and lateral cutaneous branches
from ventral rami of thoracic spinal nerves
-superficial structure
cephalic vein
travels in interval between deltoid and pectoralis major
- dives into deltopectoral triangle
- pierces costocoracoid membrane
breast changes during puberty?
increased in number of ducts
proliferation of glands
increased fat deposition
further proliferation with each menstrual cycle
pregnancy - increase in glandular tissue dramatic
supernumary?
extra rudimentary breasts or nipples
-along milk line
axillary tail
superolateral extension of breast
glandular structure of breasts?
parenchyma
apex directed toward nipple
-drained by single lactiferous duct
lactiferous sinus
storage area for secreted products
supportive structures of breast?
stroma
each lobe surrounded by connective tissue
-rests upon deep fascia
fat in breast
between glandular tissue and skin
coopers ligaments
collagens bundles within superficial fascia and run between the skin and deep fascia
sphincter in nipple?
smooth muscle layer
-sphincter for excretory ducts
mammary glands?
modified sweat glands
no fibrous capsule
no specialized vascular supply, nerve, or lymph drainage
vascular supply of the breast?
internal thoracic artery sends perforating arteries through intercostal spaces 2-4
lateral thoracic artery (2nd portion of axillary artery)
anterior and lateral cutaneous branches of intercostal arteries 3-5 (enter gland from deep side)
veins of breast?
venae comitantes of arterial supply
lymphatic drainage of breast
75% to axillary lymph nodes
25% to parasternal nodes
drainage can also go to other side
-circumareolar
attachment of pectoralis major
origin:
medial inferior border of clavicle, manubrium, sternum, costal cartilage 2-6, external abdominal oblique aponeurosis
insertion:
crest of greater tubercle of humerus
action of pectoralis major
adducts and medially rotates humerus
clavicular head flexes humerus
innervation of pectoralis major
medial and lateral pectoral nerves
attachment of pectoralis minor
origin:
outer surface of rib 3-5 )or 2-5)
insertion:
coracoid process of scapula
action of pectoralis minor
protracts and depresses scapula
also, accessory muscle for respiration
innervation of pectoralis minor
medial pectoral nerve
attachment of subclavius
origin:
upper border of 1st rib and costal cartilage
insertion:
inferior surface of clavicle
action of subclavius
pulls lateral end of clavicle downward and forward
resists excessive elevation and protraction
innervation of subclavius?
nerve to subclavius
clavipectoral fascia
envelopes subclavius and pectoralis minor
costocoracoid membrane
upper portion of clavipectiral fascia
medial and lateral attachments
-spans interval between subclavius and pec minor
what pierces costocoracoid membrane
cephalic vein
thoracoacromial artery
lateral pectoral nerve
suspensory ligament of axilla
lower portion of clavipectoral fascia after it sweeps from both sides of pec minor to form single thickened sheet which terminates at floor of axilla
**dome-like configuration of the axilla floor
axilla
tetrahedral shaped space at junction of upper limb and thorax
-boundaries form a passageway for nerves from neck and vessels from thorax
apex of axilla?
junction of clavicle, scapula, and first rub forming the cervicoaxillary canal
base of axilla?
axillary fascia
anterior wall of axilla?
pectoralis major and minor and clavipectoral fascia
posterior wall of axilla?
scapula with associated musclulature:
subscapularis
teres major
latissimus dorsi
medial wall of axilla?
ribs 1-4 or 5 with associated intercostal musculature covered b serratus anterior muscle
lateral boundary of axilla?
junction of anterior and posterior axillar walls at intertubercular groove
contents of axilla?
- axillary artery and branches
- axillary vein and tributaries
- cords and branches of brachial plexus
- proximal portions of long and short heads of -biceps brachii and coracobrachialis mm.
- axillary lymph nodes
- fat
axillary sheath?
extension of prevertebral cervical fascia that surrounds axillary artery, veins, and brachial cords
limits of axillary artery?
continuation of subclavian artery lateral to lateral border of 1st rib
becomes brachial artery distal to inferior border of teres major
branches of axillary artery?
separated into three regions
area 1 of axillary artery?
medial to pectoralis minor
-supreme thoracic artery
supreme thoracic artery
first branch of the axillary artery (area 1)
-from inferior surface and goes down to supply intercostal space 1 and 2
area 2 of axillary artery?
deep to pectoralis minor
thoracoacromial artery
lateral thoracic artery
thoracoacromial artery
in area 2 of axillary
posterior to pectoralis minor
-medially and pierces costocoracoid membrane
artery possesses a trunk and divides
axillary artery courses where?
over 1st rib
under pectoralis minor
over teres major
lateral thoracic artery
in area 2 of axillary
arises behind pectoralis minor and courses inferiorly parallel to its lateral border
branches to lateral intercostal spaces, serratus anterior, pectoralis major and minor, and mammary gland
divisions of thoracoacromial artery?
acromial
clavicular
deltoid
pectoral
AC/DP !!
area 3 of axillary artery?
subscapular artery
anterior circumflex humeral artery
posterior circumflex humeral artery
largest and most inconsistent branch?
subscapular artery
subscapular artery
very large and inconsistent
first branch of area 3
bifurcates
bifurcation of subscapular artery?
circumflex scapular artery
thoracodorsal artery
circumflex scapular artery
bifurcation of subscapular artery
courses posteriorly through triangular space to participate in scapular anastomosis
thoracodorsal artery
bifurcation of subscapular artery
courses with thoracodorsal nerve on anteromedial surface of latissimus dorsi
THORACODORSAL WILL BE ON THE PRACTICAL
anterior circumflex humeral artery
from area 3 of axillary
arises from anterolateral surface of axillary artery in region of surgical neck
*anastomoses with the posterior portion
posterior circumflex humeral artery
arises on anteromedial aspect of axillary artery at surgical neck
courses posteriorly with axillary nerve through the quadrangular space to anastomose with anterior
what to know about circumflex humeral arteries?
can arise from common trunk
anterior circumflex humeral is always smaller
cephalic vein
laterally
basilic vein
medial
median cubital vein
connects cephalic and basilic at cubital fossa
deeper veins?
named with the arteries they follow
deep veins distal?
lie medial to artery
deep veins proximal?
anterior and inferior to artery
axillary vein?
formed by union of basilic vein (medial) with brachial veins
**its tributaries are named for branches of axillary artery with which they travel
cephalic vein
at clavipectoral fascia pierces to join axillary vein
superficial lymphatics of upper limb?
drain subcutaneous structures
-drain from dorsum ventrally and from distal proximally
lymphatic collecting ducts
follow course of superficial veins
-most following basilic veins and ending in lateral group of axillary lymph nodes
axillary lymph nodes
20-30 in number
five groups:
- pectoral
- lateral
- subscapular
- central
- apical
all infraclavicular
apical lymph node
located behind or superior to pectoralis minor tendon
all drainage to what?
apical nodes > subclavian lymph trunk > right lymphatic trunk > right jugulovenous angle
