Pectoral and Axillary Regions Flashcards
Which ribs are “true” ribs?
ribs 1-7
which ribs are atypical?
1,2, 11, & 12
what ribs are “false” ribs?
ribs 8-10
what ribs are “floating” ribs?
11 & 12
what innervates the breast?
intercostal n. 4-6
what attaches the dermis of overlying skin of breast?
suspensory ligaments (Cooper’s ligaments)
arterial supply to breast?
mammary branches from anterior intercostal, lateral thoracic, and internal thoracic arteries
originally subclavian and axillary a.
a 57yo female pt presents with tenderness and swelling in the inferolateral quadrant of her right breast. Upon exam, her clinician notes enlarged lymph nodes in pt right axilla. Pathway of lymph drainage?
most lymph from breast drains to pectoral then axillary lymph nodes
Besides the 4th-6th intercostal n. what else may supply innervation of breast tissue?
supraclavicular n. branches
the deltopectoral triangle is also referred to as?
clavipectoral triangle
what is the deltopectoral triangle surrounded by?
clavicle, deltoid, pectoralis major
what are 3 things within superficial fascia of pectoral region?
platysma,
supraclavicular n.,
anterior & lateral branches of intercostal n.
what is contained within the deltopectoral triangle?
cephalic v., deltopectoral lymph nodes, deltoid branch of thoracoacromial a. (from axillary a; supply to deltoid)
what things does the clavipectoral fascia attach to?
clavicle and anterior thoracic wall
what does the clavipectoral fascia become?
suspensory ligament of axilla
What pierces clavipectoral fascia?
cephalic v., thoracoacromial a., and lateral pectoral n.
muscles of the pectoral region are innervated by?
ventral rami of spinal nerves via branches of the brachial plexus
innervation of pectoralis major?
lateral and medial pectoral nerves (C5, C6 clavicular portion, C7, C8, T1 sternocostal portion)
blood supply to pectoralis major?
pectoral branches of thoracoacromial arterial trunk
distal attachment of pectoralis major?
lateral lip of intertubercular sulcus (bicipital groove)
proximal attachment of pectoralis major?
clavicular and sternocostal attachments
ant. surface of medial 1/2 of clavicle
ant. surface of sternum and superior 6 costal cartilages
MAIN action of pectoralis major?
adducts and medial rotates humerus
secondary actions of pectoralis major?
draws scap. ant & inf (via clavicle)
clavicular portion flexes humerus
sternal portions extends humerus while in flexed position
medial pectoral nerve arises from what cord?
medial cord
lateral pectoral nerve arises from which cord?
lateral cord (not named for position within body!!!!)
a pt arrives to ED with knife protruding from left ant shoulder, just above the armpit, below clavicle. What artery is likely ligated?
axillary a.
pectoral region is primarily supplied by what artery?
axillary
pt arrives to ED with knife protruding from L ant. shoulder, just above armpit, clinician determine that lacteraction is in 3rd part of axillary a., just proximal to its large tributary, the subscapular a. what muscle is a landmark that divides the axillary into 3 main parts?
pectoralis minor
part one of the axillary a. is what in relation to P. minor?
proximal/medial
part one of axillary a. branches into what a?
superior thoracic a.
Part 2 of axillary a. is what in relation to P. minor?
behind
what does part 2 of axillary a. branch into?
thoracoacromial trunk (pectoral, deltoid, acrocromial, and clavicular branches) and lateral thoracic a.
same knifed patient, 3rd part of axillary artery. Although this injury threatens pt’s blood supply to upper extremity, the clinicians are not overly concerned because collateral blood supply to the rest of the upperd limb is possible via what anastomosis?
Scapular
what vein drains the pectoral region?
the axillary v.
basilic veins continue as the…?
axillary v.
where does the cephalic v drain into?
axillary before it becomes the subclavian
what makes up the apex of the axilla?
clavicle, scapula, and 1st rib
base of the axilla?
skin and superficial fascia, anterior axillary fold (pec major), posterior axillary fold (lat dorsi, teres major), chest wall (serratus anterior)
anterior wall of axilla?
(clavicle and subclavius), pectoralis major and minor
posterior wall of axilla?
scapula, subscapularis, latissimus dorsi, teres major
lateral boundary of axilla?
intertubercular sulcus (bicipital groove), tendon of long head of biceps, coracobrachialis tendon
contents of axilla
axillary sheath around: axillary v., axillary a., and brachial plexus (cephalic and basilic v. too?)
