Thoracic cage

Question 1

Functions of thoracic cage

Answer 1

1. Protect the contents of the pleural and pericardial sacs

2. Permit movements associated with respiration

Question 2

Manubrium

Answer 2

• T3/4 level
• Sternoclavicular joint (plane synovial joint with fibrocartilage joint disc)
• Jugular/suprasternal notch

Question 3

Body of sternum

Answer 3

• Sternomanubrial joint/sternal angle at T4/5/rib 2 (secondary cartilaginous joint)

Question 4

Xiphoid process/xiphisternum

Answer 4

• Symphysis joint
• T9 level
• Dermatome 6

Question 5

Typical rib (3-9)

Answer 5

• Rounded superior and sharp inferior borders
• Costal sulcus/groove: intercostal vessels and nerve
• Pit for costal cartilage
• Head
• Neck
• Tubercle
• Angle

Question 6

Costovertebral joints

Answer 6

• Synovial plane
• Head of rib
• Bodies of vertebrae (same level and above)

Question 7

Costotransverse joints

Answer 7

• Synovial plane
• Tubercle of rib
• Articular facet of transverse process of vertebrae

Question 8

True ribs

Answer 8

• Ribs 1-7

- Vertebrosternal attachments

Question 9

False ribs

Answer 9

• Ribs 8-10

- Vertebrochondral attachments

Question 10

Floating ribs

Answer 10

• Ribs 11 and 12

- Vertebral attachments

Question 11

First rib

Answer 11

• Atypical, true rib
• Short, wide and flat and articulates with T1 only
• Scalene tubule (area of attachment of anterior scalene muscle)
• Groove for subclavian vessels (vein = anterior) and lowest brachial plexus trunk (posterior)

Question 12

Typical thoracic vertebrae

Answer 12

• Intermediate and heart shaped body
• Demi-/superior costal facets on body (costovertebral joint)
• Vertebral foramen
• Intervertebral foramen
• Neural arch: lamina and pedicle
• Transverse process (with articular facet for tubercle of rib)
• Long, slender, non-bifid spinous process that slopes downward

Question 13

Anterior boundary of thoracic cage

Answer 13

• Sternum

- Costal cartilages

Question 14

Posterior boundary of thoracic cage

Answer 14

• T1-12 vertebrae

Question 15

Lateral boundary of thoracic cage

Answer 15

• Ribs 1-12

Question 16

Superior boundary of thoracic cage

Answer 16

• Thoracic inlet

T1 vertebrae, 1st ribs and costal cartilage, superior border of manubrium

Question 17

Inferior boundary of thoracic cage

Answer 17

• Diaphragm
• Thoracic outlet
  T12 vertebra, 11th and 12th ribs, 7-10 costal cartilages and xiphoid process

Question 18

Movement of thorax during breathing

Answer 18

Elevation of ribs

• pump handle (anteroposterior)
• bucket handle (lateral)