Thoracic Wall & Pleural Cavity

Question 1

Categorize the 12 pairs of ribs

Answer 1

• 1-7: vertebrocostal (true)
• 8-10: costochondral (false)
• 11 & 12: vertebral (floating)

Question 2

At what vertebral level are the following parts of the sternum:

• Jugular notch
• Manubrium
• Sternal angle
• Body
• Xiphoid process

Answer 2

• Jugular notch: T2
• Manubrium: T3-4
• Sternal angle: T4-5
• Body: T5-9
• Xiphoid process: T10

Question 3

Is the thoracic wall shrinking or expanding during forced expiration - what does this look like?

Answer 3

Shrinking - ribs move downwards to force air out of lungs

Question 4

What is orientation of the nerve fibers of the three intercostal muscles?

Answer 4

• External: infero-medial (hands in pockets)
• Internal: infero-lateral
• Innermost: infero-lateral

Question 5

What are the origins of the abdominal diaphragm?

Answer 5

• Xiphoid process
• Costal cartilages
• Ribs 11-12
• Crura (left and right)

Question 6

What is the name of the ligament that unites the two crura?

Answer 6

Median arcuate ligament

Question 7

What is the insertion of the abdominal diaphragm?

Answer 7

Central tendon

Question 8

What are the motor and sensory innervations of the abdominal diaphragm?

Answer 8

• Motor: phrenic nn. (C3-5)
• Central sensory: phrenic nn.
• Peripheral sensory: inferior IC nn.

Question 9

What are the three openings of the abdominal diaphragm and at what vertebral level is each located?

Answer 9

• IVC at T8
• Esophagus at T10
• Aorta at T12
  “I 8 10 Eggs At 12”

Question 10

What are the 4 minor muscles of the thoracic wall?

Answer 10

• Serratus posterior superior
• Serratus posterior inferior
• Levator costarum
• Transversus thoracis

Question 11

Which muscles do the VANs of each rib run between?

Answer 11

Internal intercostal and innermost intercostal muscles

Question 12

What are the two primary suppliers of the thoracic wall? What are the branches of these suppliers?

Answer 12

• Internal thoracic aa. (anteriorly): branch into anterior intercostal aa.
• Thoracic aorta (posteriorly): branch into posterior intercostal aa.

Question 13

What are the terminal branches of the internal thoracic aa.?

Answer 13

Musculophrenic aa. (run laterally) and the Superior epigastric aa.

Question 14

What is the origin of the medial and lateral mammary aa. branches in the breast?

Answer 14

• Medial come from internal thoracic a.

- Lateral comes from lateral thoracic aa. and posterior intercostal aa.

Question 15

Where do the medial mammary and lateral mammary veins drain into?

Answer 15

Mostly axillary v. but also some into internal thoracic vv. and some to posterior intercostal vv.

Question 16

What are the three lymphatic drainage areas of the breast?

Answer 16

• Subareolar plexus
• Axillary nodes
• Parasternal nodes

Question 17

What is the name of the potential space in the pleural cavity that can fill with fluid? What is the treatment?

Answer 17

Costodiaphragmatic recess

- Treatment: Thoracentesis (fluid aspirated at the midaxillary line, between ribs 9 and 10)

Question 18

What are the 3 impressions of the left lung?

Answer 18

• Cardiac
• Aortic arch
• Thoracic aorta

Question 19

What are the 4 impressions of the right lung?

Answer 19

• Cardiac
• SVC
• Arch of Azygos
• Esophagus

Question 20

What is the name of the cartilage of the trachea at the C6 level?

Answer 20

Cricoid cartilage

Question 21

Which side is it more common to trap foreign objects in the primary bronchi? Why?

Answer 21

Right because it is wider and more vertical

Question 22

Which of the pleura are visceral or somatic?

Answer 22

• Visceral: visceral (closer to organ)

- Somatic: parietal (closer to body wall)

Question 23

What are the parasympathetic and sympathetic branches of the visceral pleura of the lungs?

Answer 23

• Parasympathetic: Vagus nn. (bronchoconstriction, gland secretion)
• Sympathetic: Cardiopulmonary splanchnic nn. (bronchodilation)

Question 24

What are the innervations for sensory in the parietal pleura of the lungs?

Answer 24

Sensory primarily from adjacent intercostal nn.; Mediastinal sensory from phrenic nn.