Pectoral region Flashcards
What is the median furrow
it is between the sternal attachments of the pectoralis major mm
What is the sternal angle
angle made between manubrium and sternum at point of junction with second rib (TV4-TV5 vertebral disc space)
What is the lateral border of pectoralis major
anterior axillary fold
where is the deltopectoral triangle
space at the junction of the clavicle with the deltoid and pectoralis major mm
where is the deltopectoral groove
between deltoid and pectoralis major mm
What levels give rise to supraclavicular nerves
C3 C4 and anterior and lateral cutaneous branches of ventral rami of thoracic spinal nn
what are the superficial arteries in pectoral region
anterior perforating aa of internal thoracic a and the lateral cutaneous branches from posterior intercostal aa
where does cephalic vein join
costocoracoid membrane to join axillary v
What happens to the breast during puberty
increase in the # of ducts and proliferation of glands
What happens to breast when pregnant
increases glandular tissue dramatically
Where do nipples develop along
milk line
Where are nipples normally found in adult women
between 2nd and 6th ribs from lateral border of sternum to anterior or mid-axillary line
what is the general shape of the breast
smooth conical with superolateral extension known as axillary tail
Why is the skin of the areola irregularly elevated
areolar glands
Describe the parenchyma of the breast
15-20 lobes composed of tubule-alveolar glands
pyramid shape apex toward nipple
each lobe drains into nipple via lactiferous duct
What lays proximal to the openings of the lactiferous ducts
lactiferous sinus which serves as storage for secreted products
Describe the supportive structures for the breast lobes specifically
surrounded by CT
what type of CT surrounds entire mammary gland
loose CT
Where is fat distributed in the breast
between glandular tissue and skin
What are the suspensory ligaments of the breast?
collagen bundles within superficial fascia that run between skin and deep fascia “Cooper’s” ligaments
What type of muscle is located on breast and what for
smooth mm around nipple and areola to act as sphincter for excretory ducts by rhythmic contraction, helps empty lactiferous ducts
What type of modified gland are mammary glands
modified sweat glands
What morphologic features are absent in mammary glands
no fibrous capsule, no “specialized” vascular, nerve supply or lymph drainage
What arteries supply breasts
Internal thoracic sends perforation aa through intercostal spaces 2-4
lateral thoracic a sends direct branches
Anterior and lateral cutaneous branches of intercostal aa 3-5
What veins drain breasts
venae comitantes of aa supply
send to internal thoracic lateral thoracic and intercostal vv
Describe lymphatic drainage of breasts
follow vv drainage
75% to axillary lymph nodes
25% to parasternal nodes(internal to thorax paralleling internal thoracic a)
Origin and Insertion of Pec Major
Origin: medial inferior border of clavicle, manubrium, sternum, costal cartilages 2-6, and external abdominal oblique aponeurosis
Insert: crest of greater tubercle of humerus
What is the action of pec major
adducts and medially rotates the humerus; clavicular head flexes humerus
What innervates pec major
medial and lateral pectoral nn of medial and lateral cord levels
Origin and insertion of pec minor
origin: outer surface of ribs 3-5 sometimes 2-4
insertion: coracoid process of the scapula
What is the action of pec minor
protracts and depresses the scapula (also access mm for respiration)
What innervates pec minor
medial pec nerve off of medial cord
Origin and insertion of subclavius
origin: upper border of 1st rib and costal cartilage
insertion: inferior surface of clavicle
What is the action of subclavius m
pulls lateral end of clavicle downward and forward, thereby acting to resist excessive shoulder elevation and protraction
What innervates subclavius
nerve to subclavius
What makes up the clavipectoral fascia
costocoracoid membrane and suspensory lig of the axilla
What is the clavipectoral fascia
fascia which envelopes the subclavius and pectoralis minor mm
What is the costocoracoid membrane
term applied to the upper portion of the clavipectoral fascia (medial and lateral attachments)
What structures pierce costocoracoid membrane
cephalic v
thoracoacromial a
lateral pec nerve
what is the suspensory lig of axilla
lower portion of clavipectoral fascia after it sweeps both sides of pec minor to form single thickened sheet which terminates by fusing with the axillary fascia at floor of axilla
What structure provides the dome like configuration to the floor of axilla
suspensory ligament of axilla
