Axilla and Pectoral Region Flashcards
osteological structures of pectoral region
clavicles sternum ribs scapula humerus
three parts of the sternum
manubrium
body
xiphoid
where do the ribs articulate?
thoracic vertebrae and some sternum
which ribs are atypical?
1, 2, 11, 12
1 and 2 are shorter than regular ribs and 11 and 12 are floating
which ribs are the true ribs?
1-7
which ribs are false ribs?
8-10
they merge with the cartilage of 7 then merge with sternum
point to your jugular notch
on sternum, top middle
sternal angle
where the second rib attaches
bilateral glandular structures found in both males and females
breast
modified sweat glands of the breast are called
mammary glands
where does the breast rest?
on the pectoral fascia (above the pectoralis major)
potential space between breast and pectoral fascia is the
retromammary space
what nerves innervate the breast?
4th-6th intercostal nerves
what attaches the breast tissue to the dermis of the skin?
suspensory ligaments
where do the mammary gland lobules converge?
the nipple
what arteries supply the breasts?
mammary branches from anterior intercostal, lateral thoracic and internal thoracic arteries
what veins drain the breast?
axillary vein via thoracic vein and medial mammary veins
some drainage to internal thoracic vein via intercostal veins
why is lymphatic drainage of the breast particularly clinically relevant?
due to high amounts of breast cancers and its role in their metastasis
what lymphatic drainage is used for the nipple. areola, and lactiferous lobules?
subareolar lymph nodes
greater than 75% of lymph from the breast is drained by what?
axillary lymph nodes (pectoral, central, apical)
what drains the remaining lymph (last 25%) of the breast?
parasternal and abdominal lymph nodes
what innervation exists at the breast tissue?
anterior and lateral branches of 4-6th intercostal nerves
also some supraclavicular nerve branches
what does the fascia of the pectoral region consist of?
superficial and deep layers that define borders, invest muscles and create potential spaces
superficial fascia of the pectoral region is composted of
platysma
supraclavicular nerves
anterior and lateral branches of intercostal nerves
what composes the deltopectoral triangle?
deltoid, pectoralis major, and middle clavicle
cephalic vein
deltopectoral lymph nodes
deltoid branch of thoracoacromial artery
what’s the function of the clavipectoral fascia?
invests subclavius and pectoralis major
attaches clavicle and anterior thoracic wall
perched by lateral pectoral nerves, cephalic vein, and thoracoacromial artery
becomes suspensory ligament of axilla
what are the muscles of the pectoral region?
pectoralis major
subclavius
pectoralis major
serratus anterior
proximal attachments of pectoralis major
clavicular and sternocostal attachment
anterior surface of medial 1/2 of clavicle
ant. surface of sternum and superior 6 costal cartilages
distal attachment of pectoralis major
lateral lip of intertuburcular sulcus
actions of pectoralis major
adducts and medial rotation of humerus
draws scapula anteriorly and inferiorly (via clavicle)
flexes humerus (clavicular portion)
sternal person extended humors while it is flexed
blood supply of pectoralis major
pectoral branch of throacoacromial arterial trunk
innervation of pectoralis major
lateral and medial pectoral nerves (C5, C6 clavicular portion, C7, C8, T1 sternocostal portion)
origin of pectoralis minor
3rd-5th ribs, near costal cartilage
insertion of pectoralis minor
coracoid process of scapula
actions of pectoralis minor
stabilizes scapula by pulling it anteriorly and inferably against posterior thoracic wall
blood supply of pectoralis minor
pectoral branches of thoracoacromial arterial trunk
innervation of pectoralis minor
medial pectoral nerve (C8, T1)
origin of subclavius
junction of 1st rib and its costal cartilage
insertion of subclavius
inferior surface of middle 1/3 of clavicle
actions of subclavius
anchors and depresses clavicle
blood supply of subclavius
clavicular branches of throacoacromial arterial trunk
innervation of subclavius
nerve to subclavius (C5, C6)
origin of serratus anterior
external surfaces of lateral parts of ribs 1-9
insertion of serratus anterior
anterior surface of medial border of scapula
actions of serratus anterior
protracts scapula
rotates scapula
holds scapula against thorax
blood supply of serratus anterior
lateral thoracic artery
innervation of serratus anterior
long thoracic nerve (C5, C6, C7)
arteries of the pectoral shoulder and axillary regions
subclavian artery and axillary artery
origin of subclavian artery
brachiocephalic trunk and aortic arch
where does the subclavian artery arise?
posterior to sternocalvicular joint
3 divisions of subclavian artery
- medial to anterior scalene muscle
- posterior to anterior scalene muscle
- lateral to anterior scalene muscle
branches of medial part of subclavian artery
internal thoracic (mammary) artery
vertebral artery
thyrocervical arterial trunk
branches of the thyrocervical arterial trunk
transverse cervical artery (superficial and deep branches)
inferior thyroid artery
ascending cervical artery
supra scapular artery
cervicodorsal tunk
when the superficial and deep branches of transverse cervical arteries form an arterial trunk
branches of posterior part of subclavian artery
costocervical arterial trunk composed of supreme intercostal artery and deep cervical artery
Origin (arises from) dorsal scapular artery
May arise independently from the lateral part of the subclavian artery or from the transverse cervical artery of posterior part
where does the subclavian become the axillary artery?
lateral border of first rib
part 1 of axillary artery
super thoracic artery
part 2 of axillary artery
thoracoacromial trunk
part 3 of axillary artery
sub scapular artery
anterior circumflex humeral
posterior circumflex humeral
branches of thoracoacromial trunk of axillary artery
pectoral branch, deltoid branch, acormial branch, clavicular branch
branches of the sub scapular artery of the axillary artery
circumflex scapular
thoracic dorsal
anastomoses of the arterial branches in pectoral region
supra scapular artery dorsal scapular artery posterior intercostal arteries circumflex scapular arteries thoracodorsal artery
axillary vein
drains the pectoral and axillary region, follows axillary artery, received blood from superficial and deep veins of arm and forearm
branches of the axillary vein
deep brachial veins
superficial veins of arm and forearm
superficial veins of arm or forearm
basilic veins (continue to axillary) cephalic veins (drain to axillary before becoming subclavian)
boundaries of axilla at apex
clavicle
scapula
1st rib
boundaries of axilla at base
skin and superficial fascia
anterior axillary fold (pec. major)
posterior axillary fold (lats, teres major)
chest wall (serratus anterior)
boundaries of axilla at anterior wall
(clavicle) (subclavius) pectoralis major pectoralis minor
boundaries of axilla at posterior wall
scapula
subscapularis
latissimus dorsi
teres major
boundaries of axilla laterally
inter tubercular sulcus
tendon of long head of biceps
coracobrachialis tendon
3 contents of the axilla
axillary vein
axillary artery
brachial plexus
