Module 4: Thoracic Wall and Mediastinum Flashcards
What are the boundaries of the thoracic cavity?
posterior: spine
anterior: sternum
inferior: diaphragm
superior: superior thoracic aperture
What are the contents of the thoracic cavity?
respiratory and cardiovascular organs
What are the compartments of the thoracic cavity?
pleural cavity: Right and Left
Mediastinum: superior and inferior (midline)
What are the components of the thoracic wall?
-skin
-subcutaneous tissue
-ribs
-intercostal muscles
What is the function of the thoracic wall?
- protection
- respiration
- muscle attachment
What are the 3 different types of ribs?
True: 1st-7th
- direct cartilaginous attachment to sternum
False: 8th-10th
- indirect connection (come together to connect to sternum)
Floating: 11th and 12th
- do not attach to sternum
What is the general structure of a rib?
head
neck
costal tubercle
costal angle(posterior)
body/shaft
What are the 3 rib joints and their synovial classification?
costovertebral: head»_space; vertebral body
costotranverse: costal tubercle»_space; transverse process
sternocostal: sternum»_space; costal cartilage
plane/gliding
What are the unique landmarks of the 1st rib?
scalene tubercle
groove for subclavian artery
groove for subclavian vein
What is the position of the anterior scalene muscle relative to the subclavian artery?
anterior to subclavian artery
What are the unique landmarks of the sternum?
manubrium
- jugular and clavicular notch/facet
body
- sternal angle (joint between manubrium and body)
- costal notches/facets
xiphoid process
Where does the 2nd rib attach to the sternum?
sternal angle
What are the muscles of the thoracic wall?
external intercostal
internal intercostal
innermost intercostal
tranversus thoracis
diaphragm
What are the OIAN for the external intercostal?
O: rib superior-lateral
I: rib inferior medial
A: elevation of ribs
N: intercostal nerve (segmental)
start from spine, do not reach sternum
What are the OIANs of the internal and innermost intercostal muscles?
O: rib superior-medial
I: rib inferior-lateral
A: depression of ribs
N: intercostal nerve (segmental)
start from sternum, do not reach spine
What are the OIANs of the tranversus thoracis muscle?
O: posterior sternum
I: costal cartilages
A: depress ribs
N: intercostal nerves (segmental)
What are the OIANs of the diaphragm?
O: xiphoid process, inner surface of lower ribs, costal cartilages, lumbar vertebrae via crura
I: central tendon
A: inspiration(negative pressure)
N: phrenic nerve c3-5 (R+L)
What are the actions of the sternum and ribs during expiration?
sternum: move downward and back
ribs: depress and move middle of shaft medially (bucket handle)
What are the actions of the ribs and sternum during inspiration?
sternum: moves upward and forward (pump handle)
ribs: elevate and move middle of shaft laterally
What is the naming convention of intercostal nerves?
T1-6: upper intercostal
T7-11: lower intercostal
T12: subcostal
What are the major landmarks of the innervation of the thoracic wall?
T4: nipple line
T6: skin over xiphoid
T10: umbilicus
What branches of arteries come off of the descending aorta?
bronchials
esophageal
posterior intercostals (3-11)
subcostal (12)
What arteries branch off th internal thoracic artery?
pericardiophrenic a.
anterior intercostals (1-6)
superior epigastric
musculophrenic
What artery do the anterior intercostal arteries (7-9) branch off of?
musculophrenic artery