Thorax Anatomy Flashcards
Regions of the Anterior Thorax

The Five Trunk Lines
Midsternal line (anterior median) is a vertical line through the midline of the sternum.
Midclavicular lines run through the midpoint of the clavicles parallel to the midsternal line.
Midaxillary line is a vertical line that runs inferiorly from the deepest part of the axilla.
Midvertebral line (posterior median) is a vertical line through the vertebral column.
Scapular lines are parallel to the midvertebral line and cross the inferior angle of the scapula.

Anterior Thorax Vasculature

Lateral Thorax Vaculature

Posterior Thorax Vasculature

The major lymph nodes of the upper trunk are the. . .
axillary lymph nodes
The skin above the manubriosternal joint is supplied by sensory fibers from
the lower cervical plexus (C3, C4 and C5)

Below the manubriosternal joint and to the upper epigastric region is innervated by
the intercostal nerves (anterior primary rami of the T1-T12)
There is considerable ___ between neighboring dermatomes.
There is considerable overlap between neighboring dermatomes.
Auscultating the Aortic Valve
right 2nd intercostal space, just lateral to the sternum.

Auscultating the Pulmonary Valve
left 2nd intercostal space, just lateral to the sternum.

Auscultating the Tricuspid Valve
left 5th intercostal space, just lateral to the sternum.

Auscultating the Mitral Valve
left 5th intercostal space, midclavicular line.

The costal cartilages of ribs ____ articulate with the sternum via sternocostal joints, while the costal cartilages of ribs ____ articulate with one another at interchondral joints to form the costal margin.
The costal cartilages of ribs 1-7 articulate with the sternum via sternocostal joints, while the costal cartilages of ribs 8-10 articulate with one another at interchondral joints to form the costal margin.
symphesis (plural sympheses)
immovable joint
“False ribs”
Ribs 8-10, which are conjoined by cartilage to one another but are not conjoined directly to the sternal body.
“Floating ribs”
Ribs 11-12, which have no joints with other ribs or the sternal body and are mostly posterior.
Sections of thoracic wall muscle
Outer layer: External intercostal muscles
Middle layer: Internal intercostal muscles
Inner layer: Innermost intercostal muscles (and transversus thoracis, subcostal muscles)

Accessory Respiratory Muscles
Not shown is the abdominal wall muscle, also an accessory respiratory muscle.

Intercostal neurovasculation
Blood supply and nerve innervation resides in each intercostal segment just inferior to the superior rib of the intercostal space. They run in the following order:
Vein
Artery
Nerve
(VAN)
Intercostal Nerves
Intercostal nerves run below each rib and they are distributed to the thoracic wall, intercostal muscles, parietal pleura, periosteum of the ribs, abdominal wall and the peritoneum.

Intercostal arteries
posterior intercostal arteries (main intercostal arterial supply) are branches of the thoracic aorta; anterior intercostal arteries arise from the internal thoracic artery and anastomose with the respective posterior intercostal artery. Intercostal arteries run below each rib and supply the intercostal muscles - with additional branches from the subclavian and axillary arteries - the pectoralis muscles, the breast and the skin.

Intercostal veins
Intercostal veins accompany the intercostal arteries. They drain into the azygos system and internal thoracic veins.

Intercostal lymphatics
The lymph vessels of the intercostal spaces follow the intercostal vessels.






































