Thoracic Wall, breast, and lungs Flashcards
What do mammary glands derive from?
Modified sweat glands
Innervation of breast
supraclavicular nerve from cervical plexus, anterior cutaneous nerves 2-6 or 7, and lateral cutaneous nerves 3-6 or 7 (both derived from cutaneous branches of intercostal nerves from ventral roots of T1-T11
Vascular Supply of Breast
Lateral mammary artery (from axillary a. then lateral thoracic a.) Medial mammary arteries (1st 4-5 perforating arteries from the internal thoracic arteries derived from subclavian artery) and Lateral mammary arteries from lateral cutaneous arteries (Derived from posterior intercostal arteries from thoracic aorta)
75% of breast lymph flow
Goes to axillary nodes (pectoral nodes, central nodes, and apical nodes)
20% of breast lymph flow
Goes to parasternal nodes along internal thoracic vessels
5% of breast lymph flow
Flows to abdomen (diaphragm or liver) or breast on opposite side.
Polymastia
Supernumerary breast
Polythelia
Supernumerary nipples
Tubercle of rib articulation
Articulates with transverse process of vertebrae
Head of rib articulation
Articulates with two vertebral bodies, vertebrae of same number and vertebrae above.
True Ribs
1-7
False Ribs
8-12
External Intercostal Muscles
11 pairs, fibers pass down and forward, anteriorly becomes external intercostal membrane, begin at vertebrae and end at approximately costal cartilage
Internal Intercostal Muscles
11 pairs, fibers pass down and backwards (out and down), posteriorly becomes internal intercostal membrane, begin at angle of rib and go to sternum
Innermost intercostal muscles
Pass same direction as internal IC muscles (out and down), nerves and vessels lie above these muscles, anteriorly transverses thoracis, posteriorly subcostal muscles
Subcostal Muscles
Innermost on posterior thoracic wall, span 2 or more spaces
Transverse thoracic muscles
Origin at sternum, insertion at ribs, lie posterior to internal thoracic vessels, four or five slips, lie posterior to the internal thoracic vessels
Innervation of intercostal muscles
12 thoracic nerves, 11 intercostal and 1 subcostal. Both muscular and cutaneous branches.
Posterior intercostal arteries
9 posterior intercostal muscles, 3-11 that arise from the aorta. Supply the spinal cord, back, and intercostal muscles
Anterior intercostal arteries
5-6 anterior intercostal arteries come from internal thoracic artery which is a branch of the subclavian artery. The internal thoracic artery then divides into the superior epigastric artery and musculophrenic artery. Musculophrenic artery provides 3-4 anterior intercostal arteries
Supreme intercostal artery
Arises from costocervical trunk/subclavian and gives rise to the first two posterior intercostal arteries
Musculophrenic artery
Derived from internal thoracic artery. Gives rise to 3-4 anterior intercostal arteries
Anterior Intercostal Veins
6 pairs form the internal thoracic vein, 3 pairs form the musculophrenic vein and drain into the brachiocephalic vein
Costal groove
holds Vein, Artery, and Nerve (in superior to inferior order)
Where would you want to insert a needle in the thorax in relation to the costal groove?
Close to the upper surface of a rib because the costal groove is on the lower surface.
Lobar bronchi
3 on right side, 2 on left side
Segmental bronchi
10 on each side
Bronchopulmonary Segment organization
Arteries and bronchi are centrally located but veins are found between segments. Veins identify specific segments that can be used for removal.
Hilum of Right Lung
Pulmonary Artery is anterior to bronchus
Hilum of left lung
Pulmonary artery is superior to bronchus
Parasthesia
Abnormal spontaneous sensation of burning, pricking, or numbness. Usually caused by impingement, cutting, or rough handling of a cutaneous nerve
Dermatome associated with nipple
T4
Retromammary bursa
Space between body of breast and pectoral fascia. Allows breast to be very moveable.
Pectoral Nodes
Level 1, lateral to pectoralis minor
Central Nodes
Level 2, posterior to pectoralis minor
Apical Nodes
Level 3, superomedial to pectoralis minor
Manubriosternal joint
Joining of manubrium and sternum. At this level, the second rib articulates with the sternum. This is the sternal angle
Ribs 11 and 12
End freely
Ribs 8,9, and 10
Articulate with costal segments above
Anterior IC veins
Internal thoracic vein and musculophrenic vein follow the same paths as their respective arteries. 5-6 drain into the internal thoracic vein and 3 pairs drain into the musculophrenic. Both of these then go to the brachiocephalic vein.
Articulations for ribs
Head of rib articulates with superior costal facet of thoracic vertebra of same number and inferior costal facet of vertebra above. Costal tubercle articulates with the transverse process of the vertebra with the same number
