Lecture 12: Thorax & Breast Flashcards
Direction of 3 Intercostals
External (hands in pockets) Internal (Hands up shirt) Innermost (More Horizontal than Internal)
Action of Intercostals
To assist in Respiration, the externals help raise the ribs
Why are only deep back muscles innervated by dorsal Rami
Because the superficial and intermediate back muscles used to be on the side of the body evolutionarily/developmentally, when they migrated they dragged the ventral rami with them
Thoracic Dermatomes, specific landmarks
Cover Ventral and dorsal surface of the abdomen and thorax. The dermatomes slope down towards the ventral side bc the spinal nerves pass down through the intercostal groove, which also slopes down ventrally.
Nipples –> T4
zyphoid process –> T6
Bellybutton –> T10
Where to place chest tube
On superior side of inferior rib, in intercostal groove
V,A,N
Vein, Artery, Nerve, from superior to inferior. Vein drains into Azygos, Artery arises from aorta, and nerve arises from intervertebral foramen
Intercostal anastomoses
Ascending aorta –> subclavian –> internal thoracic –> anterior intercostals –> posterior intercostals –> descending aorta
Epigastric anastomoses
Internal thoracic –> Superior epigastric artery –> Internal epigastric artery –> external iliac –> common iliac –> descending aorta –> ascending aorta –> subclavian –> internal thoracic
blood supply of breast
Internal (medially) and lateral (laterally) thoracic arteries
Lymphatic drainage of thorax
Above umbilicus to axillary nodes (armpit) below umbilicus to inguinal nodes (pelvis)
Male breast enlargement
Gynecomastia –> hormone imbalance
Mammary gland
Modified sweat gland
Tail of spence
the superio-lateral end of mammary gland
In what fascia is the breast located
The superficial fascia, considered a skin gland
Retromammary space
Loose connective tissue space that separates the breast tissue/mammary gland from the deep pectoral fascia
