breast pectoral region
where does the parasternal lymphatic drain to
bronchomedialstinal lymphatic trunk
where does the humeral lymph node receive lymph from?
humeral lymph node is also known as lateral axillary lymph node. it receives lymph from the upper limb
blood supply of serratus anterior
lateral thoracic artery
mastectomy/ lumpectomy
amputation of breast or affected portion of breast
supernumerary breast (polymastia)
having > 2 breasts
where does the axillary path drain into
subclavial lymphatic trunk
thoracoacromial artery
the pectoral branch of this supplies the pectoralis major and minor -it is a branch off the axillary artery -it penetrates the claviopectoral fascia before branching into the pectoral, clavicular, deltoid and acromial arteries.
what is the axillary tail? what is it's significance? where is it in relation to lymphatic system?
upper lateral portion of breast where most breast cancers are found. -general region where the pectoral nodes are; the first nodes of the lymph to be invaded in breast cancer.
axillary tail of spence
-part of the mammary gland that extends along the inferolateral (outer) edge of pectoralis major towards the axilla (armpit) -upper lateral/outer quadrant of breast. -50% of breast cancer is located here -general region where pectoral lymph nodes are.
what is the deltopectoral triangle used as a marker of and where is it located?
-used as a marker of the cephalic vein. -it's the location where the pec major meets the deltoid meets the clavicle.
arterial supply of the breast
1) medial branches of the internal thoracic artery supply medial mammary gland 2) lateral thoracic artery- supplies lateral mammary gland **Bonus- what else does this supply? 3) thoracoacromial artery- supplies pectoral muscles, deltoid, sub clavius and shoulder joint 4) posterior intercostal arteries- branch off from descending aorta and supply lateral and posterior portions of intercostal space
origin of the pectoralis major
1) medial clavicle 2) manubrium 3) body of the sternum 4) costal cartilage from ribs 2-6 sometimes at the rectus sheath of abdominal wall.
what is the difference between the lateral and medial pectoral nerve?
The medial pectoral nerve- originates under the pectoralis minor and pierces it on its way to the inferior pectoralis major (medial= more, innervates both)- C8:T1 the lateral pectoral nerve innervates only the pectoralis major (superior) - lateral = less.
what is the mammary gland?
a gross feature of the breast is a modified sweat gland contained within the subcutaneous tissue
pectoral lymph nodes (anterior axillary). what else is in this location?
axillary tail of spence
insertion of pectoralis minor
coracoid process, hooklike structure on the edge of the scapula.
insertion of pectoralis major
crest of greater tubercule of the humerus bone
anomalies/ variations
deviation from normal
label cephalic vein. what landmark is it associated with?
dives deep into the deltopectoral triangle and terminates in axillary vein
venous drainage of breast
drains into the axillary vein and internal thoracic vein, following the arteries
function of serratus anterior
draws scapula forward inferior fibers of this muscle rotate the scapula superiorly you work this muscle when you throw a punch.
function of pectoralis minor
draws scapula forward, medialward and downward- example: you feel this muscle working when you do shoulder dips at the gym.
gynecomastia
excessive development of the male mammary glands, sometimes secreting milk. can be disease related or idiopathic
function of pectoralis major
flexes and adducts arm (brings it towards body) rotates arm medially (brings humerus towards midline as if you're squeezing chest together.
at what point does the thoracoacromial artery branch?
from the axillary artery
internal features of the breast
glandular, having the secretory glands, lactiferous ducts and lactiferous sinuses that make it a common cancer location
where does the lymph from the breast skin go to?
goes to axillary nodes, parasternal nodes, inferior deep cervical nodes and inferior clavicle
supernumerary nipples (polythelia)
having more than the normal number of nipples -can be on the breast or on other parts of the body, found along the milk line from the axilla to the groin. -Resemble raised nevi (moles)
what is the easiest way for cancer to spread in the breast
hematogeneous spread- spread cancer through intercostal veins so that you can reach the intervertebral venous plexus, the ductless set of veins where metastasis commonly happens -lymphatic vessels can carry some tumor cells to axillary lymph nodes but the way that cancer spreads the best is through the intercostal veins to venous plexus route
if the deep anterior fascia covering the pectoralis major fuses with the mammary gland's fascia, what does this indicate?
indicates breast disease.
mastitis
inflammation of the breast during breast feading caused by staphaureus. You can treat it with antibiotics, drain the abscess or excise the diseased mammary gland
innervation of serratus anterior
long thoracic nerve from ventral rami C5-C7
if you were checking for cancer where would you look?
look in the pectoral nodes (first path of axillary) and the parasternal nodes in order to check both major paths of lymph for cancer.
carcinoma
malignant neoplasm from epithelial tissue of several sites, occurring frequently in the skin, bronchi, stomach, prostate, breast, cervix and skin
insertion of serratus anterior
medial border of scapula on its deep (costal) surface
nerve supply of pectoralis minor
medial pectoral nerve (C8:T1) branches of the medial pectoral nerve usually pierce the minor in order to get to the major
external features of breast
nipple, areola -each of the 20 lactiferous sinuses has an opening on the nipple
arterial supply of pectoralis major
pectoral branch of thoracoacromial trunk
blood supply of pectoralis minor
pectoral branch of thoracoacromial trunk
where does the pectoral lymph node receive lymph from?
pectoral lymph node is also known as the anterior axillary lymph node. it receives 75% of breast lymph
what are suspensory ligaments
portions of connective tissue stroma in the superior breast that connect the lobules of the mammary gland to the underlying dermis.
scintigraphy
record indicating the intensity, location and distribution of radioactivity in tissue after injecting radioactive tracers
origin of serratus anterior
ribs 1-8 or ribs 1-9
origin of pectoralis minor
ribs 3-5 runs downward, medially from the coracoid process (the hook on the edge of the scapula).
nerve supply (innervation) of pectoralis major
superior pectoralis major innervated by lateral pectoral nerve (C5-T1) inferior pectoralis major innervated by medial pectoral nerve, C8-T1 (which also innervates the pectoralis minor)
define the subareolar lymphatic plexus
the subareolar lymphatic plexus collects lymph from the nipple, areola and breast lobules -from there 75% of it goes to the pectoral nodes and then the axillary lympathic system, draining into the subclavial trunk. distally, to the pectoral nodes, the humeral and subclavial nodes merge towards the central and apical nodes. (axillary system path 1) -25% of the subareolar plexus goes to the parasternal nodes draining into the bronchomediastinal trunk (parasternal system, path 2) -minimal amounts go to the opposite breast and the abdominal wall (paths 3 and 4)
define the lymphatic path in the axillary region
the subscapular (posterior), humeral (lateral) and pectoral (anterior) all merge into the central node, which goes to the apical node.
where does the subscapular lymph node receive lymph from?
the subscapular lymph node is also known as the posterior axillary lymph node. it receives lymph from the posterolateral trunk
what does a denervation at the thoracic nerve of serratus anterior cause?
winging of the scapula. the medial border of the scapula would fall away from the posterior chest wall and look like a wing.
what is the pectoralis minor a marker of (hard quiz question)
-cord of brachial plexus is deep to pec minor -second part of axillary artery -medial pectoral nerve. NOT a landmark for cephalic vein
