Thoracic Wall Flashcards
What are the parts of the sternum?
manubrium, body, and xiphoid process
What forms the sternal angle?
articulation of the manubrium with the body of the sternum
What is the superior opening of the thoracic cage?
superior thoracic aperture (thoracic inlet)
What is the boundaries of the superior thoracic aperture?
manubrium, first rib, and first thoracic verebra
What is the inferior opening of the thoracic cage?
inferior thoracic aperture (thoracic outlet)
What are the boundaries of the inferior thoracic aperture?
xiphoid process, costal margin, twelfth rib, distal end of eleventh rib, twelfth thoracic vertebra
What are ribs 1 to 7 which articulate with the sternum directly through their own costal cartilages?
true ribs
What are ribs 8 to 12?
false ribs
What ribs articulate with the sternum indirectly by attaching to the costal cartilage of the rib above?
ribs 8 to 10
What ribs are not connected to the sternum at all and are often referred to as floating ribs?
11 and 12
Which ribs are typical ribs?
3 to 9
Which ribs are atypical ribs?
1, 2, 10, 11, and 12
What is the morphology of a typical rib?
head, neck, tubercle, angle, shaft, and costal groove
what are the functions of the thoracic cage?
protection of thoracic and upper abdominal organs, muscle attachments, and respiration
What do the external intercostal muscles do?
elevates the ribs in inspiration
What do the external intercostal muscles do?
elevates the ribs in inspiration
What does the internal intercostal, innermost intercostal, subcostalis, and transversus thoracis muscles do?
depresses the ribs in forced expiration
What are the branches of the internal thoracic artery?
Pericardiacophrenic, anterior intercostal, musculophrenic, and superior epigastric arteries
What artery accompanies the phrenic nerve, supplies the pleura, pericardium and diaphragm?
Pericardiacophrenic artery
Anterior intercostal arteries supply what?
supply the upper 6 intercostal spaces, anastomose with the posterior intercostal arteries
What artery supplies the lateral terminal branch of internal thoracic artery?
musculophrenic artery
Superior epigastric artery supplies what?
medial terminal branch of internal thoracic artery
What supplies the posterior aspect of the thoracic wall?
supreme (superior) intercostal artery, third-eleventh posterior intercostal arteries, and subcostal artery
What veins drain the anterior thoracic wall?
internal thoracic vein (into brachiocephalic vein)
What drains the posterior aspect of the thoracic wall?
azygos veins (system)
What is the right side of the azygos system made of?
1st posterior intercostal into brachiocephalic
2nd and 3rd posterior intercostal veins form superior intercostal vein
4th-11th posterior intercostal veins and subcostal vein form azygos vein
What is the left side of the azygos system formed from?
1st posterior intercostal vein into brachiocephalic
2nd-3rd post. intercostal into superior intercostal (into brachiocephalic)
4th-8th post intercostal into accessory hemiazygos vein (into azygos on right)
9th-11th post intercostal and subcostal into hemiazygos (into azygos)
What nerves innervate the thoracic wall?
Intercostal nerves: anterior primary rami 1-11 ribs
subcostal nerve: anterior primary ramus of rib 12
What are the layers of the thoracic wall?
skin, superficial fascia, deep fascia, serratus anterior, external intercostal muscle, internal intercostal muscle, innermost intercostal muscle, endothoracic fascia, parietal pleura, pleural cavity, visceral pleura, and the lung
What is the function of the endothoracic fascia?
to prevent the innermost intercostal muscle from rubbing against the parietal pleura
What is the thickening of the fascia over the apex of the lung?
suprapleural membrane
What lies within a typical space?
intercostal vein, artery, and nerve
