5. Thoracic cage and mechanics of breathing

Question 1

Why are children more susceptible to rib fractures?

Answer 1

• bc their ribs are more elastic compared to adult ribs.

Question 2

Which part of the rib is most commonly fractured?

Answer 2

• the part of the rib just anterior to its angle.

Question 3

Which ribs are least prone to fracture and why? (2)

Answer 3

• 1 and 2 bc they are protected by the clavicle.

- 11 and 12 bc they are “floating” ribs so are more mobile.

Question 4

What are the symptoms of thoracic outlet syndrome?

Answer 4

• pain in neck and shoulder which radiates to the arm.
• temporary loss of feeling in affected arm and fingers.
• accompanied by tingling sensations.

Question 5

Which feature of the thoracic vertebra allow them to articulate with the heads of the ribs?

Answer 5

• demi-facets.

Question 6

What type of epithelium makes up the lung pleura?

Answer 6

• simple squamous epithelium.

Question 7

Which muscles increase the posterior/anterior aspect of the thoracic cavity during breathing?

Answer 7

• the external intercostals.

Question 8

Which 5 muscles can be seen during active inspiration?

Answer 8

• SCM.
• scalenes.
• latissimus dorsi.
• serratus anterior.
• pec major and minor.

Question 9

Which nerve innervates the diaphragm?

Answer 9

• phrenic nerves.

Question 10

Which nerve innervates the intercostal muscles?

Answer 10

• segmental thoracic nerves.