Thoracic cage: relations to the important venous structures

Behind the sternoclavicular joints: the brachiocephalic veins begin.

Behind the 1st costal cartilage on the right the superior vena cava begins.

Behind the 2nd costal cartilage on the right the azygos vein ends.

Behind the 3rd costal cartilage on the right the superior vena cava ends.


Rib costal groove: order of intercostal blood vessels and nerve


From superior to inferior:

  • Vein
  • Artery
  • Nerve 

Lung lobe numbers: right vs. left

Tricuspid heart valve and tri-lobed lung both on the right side.

Bicuspid and bi-lobed lung both on the left side.

Lung lobes: one having lingula, lobe numbers

Lingula is on Left.

The lingula is like an atrophied lobe, so the left lung must have 2 “other” lobes, and therefore right lung has 3 lobes.

Lung lobes: segments of right middle lobe


Segments of Middle Lobe are Medial & Lateral.


Pleura surface markings

“All the even ribs, in order: 2,4,6,8,10,12 show its route”:

Rib2: sharp angle inferiorly

Rib4: the left pleura does a lateral shift to accommodate heart

Rib6: both diverge laterally

Rib8: midclavicular line

Rib10: midaxillary line

Rib12: the back


Bronchopulmonary segments of right lung

A PALM Seed Makes Another Little Palm”:

In order from superior to inferior:

  • Apical
  • Posterior
  • Anterior
  • Lateral
  • Medial
  • Superior
  • Medial basal
  • Anterior basal
  • Lateral basal
  • Posterior basal

Bronchopulmonary segments of the left lung

Astute Anatomists Share Inside Secrets About Lungs”:

  • Apicoposterior (S1+2)
  • Anterior (S3)
  • Superior (S4)
  • Inferior (S5)
  • Superior (S6)
  • Anteromedial basal (S7+8)
  • Lateral basal (S9)

Bronchi: which is more vertical

Right on Red“:

Many places allow making a right hand turn at a red light, if you first come to a complete stop.

A child swallowing a red penny is more likely to get it stopped down the right bronchus, since it is more vertical.


Bronchi: which one is more vertical

“Inhale a bite, goes down the right“:

Inhaled objects more likely to lodge in right bronchus, since it is the one that is more vertical.

Mediastinums: posterior mediastinum structures

There are 4 birds:

The esophaGOOSE (esophagus)

The vaGOOSE nerve

The azyGOOSE vein

The thoracic DUCK (duct)

Superior mediastinum contents


  • Brachiocephalic veins
  • Arch of aorta
  • Thymus
  • Superior vena cava
  • Trachea
  • Esophagus
  • Nerves (vagus & phrenic)
  • Thoracic duct

Superior mediastinum: contents


  • Phrenic nerve
  • Vagus nerve
  • Thoracic duct
  • Left recurrent laryngeal nerve (not the right)
  • Brachiocephalic veins
  • Aortic arch (and its 3 branches)
  • Thymus
  • Trachea
  • Lymph nodes
  • Esophagus

Thoracic duct: relation to azygous vein and esophagus

“The duck between 2 gooses“:

Thoracic duct (duck) is between 2 gooses, azygous and esophagus.

Thoracic duct: which half of upper body does it drain

Know drains all of lower body, but was it the right or the left part of the upper body?

Answer: its Lymph from the Left of the upper body.


Vertebrae: number of facets a typical thoracic has

Typical Thoracic has Ten facets.


Vagal nerve: path into thorax

Vagus nerve, unlike phrenic, continues through diaphragm with esophagus–it is “Not Left Behind“:

The left vagus is anterior, right is posterior [behind].


Vagus nerve: path into thorax

“I Left my Aunt in Vegas“:

Left Vagus nerve goes Anterior descending into the thorax.


Aorta vs. vena cava: right vs. left

Aorta and right each have 5 letters, so aorta is on the right.

Vena and cava and left each have 4 letters, so vena cava is on the left.


Aortic arch: major branch order

“Know your ABC’S“:

  • Aortic arch gives rise to:
  • Brachiocephalic trunk
  • left Common Carotid
  • left Subclavian

Beware though trick question of ‘What is first branch of aorta?’ Technically, it’s the coronary arteries.

Atrioventricular valves


Left Atrium: Bicuspid

Right Atrium: Tricuspid


Cardiac valves: order in circuit

TRI berore you BI“:

Tricuspid valve is located in left heart and Bicuspid valve is located in right heart. Blood flows through the tricuspid before bicuspid.


Heart valve sequence

Try Pulling My Aorta“:

  • Tricuspid
  • Pulmonary
  • Mitral
  • Aorta

Heart valves

Toilet Paper My A$$”:

From right to left:

  • Tricuspid
  • Pulmonic
  • Mitral
  • Aortic

Heart valves: order in circuit

“First learn a Tricycle, then learn a Bicycle”:

Flow through Tricuspid first, then Bicuspid.


Thoracoacromial artery branches

CAlifornia Police Department”:

  • Clavicular
  • Acromial
  • Pectoral
  • Deltoid

Thoracoacromial artery branches


  • Acromial
  • Breast (pectoral)
  • Clavicular
  • Deltoid

 You can suggest more mnemonics …

Warm regards,

Dr. Indrajit Rana


2 responses to “Thorax

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