S1M3 Thoracic Wall/Pleural Cavity

• The clavical!
• Above the clavical: lymph flows to the inferior jugular lymph nodes
• Below the clavical: lymph from the parietal lymph nodes drain into the axillary lymph nodes!

• Jugular notch of the manubrium is located at T2 level
• Great place to palpate and located T2 clinically!

T3/T4

to locate CPR proper hand postion!

It is the inferior opening of the thorax created by: the twelfth thoracic vertebra behind, by the eleventh and twelfth ribs at the sides, and in front by the cartilages of the tenth, ninth, eighth, and seventh ribs, which ascend on either side and form an angle

• Intercostal Muscles!
• 1.)External Intercostal Muscles (run inferomedially from the rib above to the rib below--elevate ribs during forced inspiration!!!!
• 2.)Internal Intercostal Muscles (muscle fibers are at right angles to ext. intercostal m.)
• 3.)Innermost Intercostal Muscles (seperated from internal intercostal m. by intercostal nerves and vessels)
• Look at the location of the intercostal nerves in the picture above!

Skin>Superficial fascia>External intercostal muscle>internal intercostal muscle>innermost intercostal muscle>endothoracic fascia>parietal pleura

• Inject local anesthetic to block nerve conduction
• Be careful not to push needle immediately inferior to the inferior end of the rib
• Costal groove contains VAN (vein artery nerve) and injection into the inferior portion of the end of the rib can injure these structures.

• 1.From the aorta:-Posterior intercostals supply 3rd through 11th intercostal spaces
• -Subcostal artery supplies area inferior to 12th rib
• 2.From subclavian artery:-Superior intercostal from costocervical trunk supplies 1st & 2nd intercostal spaces
• 3.Anterior intercostal arteries from internal thoracic arteries
• 4.From the axillary artery:- Lateral thoracic artery

• 11pairs of posterior intercostal veins
• -One pair of subcostal vein
• -Anterior intercostal veins (tributaries of internal thoracic veins)
• -Most posterior intercostal veins end in the azygos veins
• -Azygos veins (system) is formed by the union of lumbar veins
• -Right azygos vein (1) drains into the superior vena cava (4)
• -Left hemiazygos(2) & left accessory hemiazygos azygos (3) veins drain into the right azygos vein

• Thoracic Wall: Nerves
• -Twelve pairs of thoracic spinal nerves supply the thoracic wall -The anterior rami of T1-T11 form the intercostal nerves-The anterior ramus of T12 is called the subcostal nerve
• Typical Intercostal Nerve:
• (3rd to 6th intercostal nerves)
• -Initially run within the endothoracic fascia
• -Near the angle of the rib, the nerves run between the internal intercostal & innremost intercostal muscles
• -At the angle of the rib these nerves give rise to collateral branches

1st intercostal nerve divides into a larger superior( to brachial plexus) & a small inferior parts

-2nd intercostal ( sometimes 3rd intercostal ) nerve gives rise to a large intercostobrachial nerve

-Intercostobrachial nerve communicates with the medial brachial cutaneous nerve

-7th- 11th intercostal nerves cross the costal margin and continue on to become thoracoabdominal nerves