thorax and ribs

Question 1

Answer 1

superior thoracic aperture

Anatomical thoracic inlet. the thoracic cavity communicates with the neck and upper limb through the superior thoracic aperture.
bounded posteriorly by the T1 vertebra
bounded laterally by the first pair of ribs and their costal cartilages
bounded anteriorly by the superior border of the manubrium

Question 2

inferior thoracic aperture

Answer 2

anatomical thoracic Outlet.

• much larger than superior
• diaphragm closes ITA
• bounded : posteriorly by T12 vertebra, posterolaterally by 11th and 12th ribs, anterolaterally by joined costal cartilages of ribs 7-10 forming costal margins, anteriorly by xiphisternal joint (superior part of xiphoid process)56

Question 3

groups of ribs

Answer 3

true (vertobrosternal) ribs
-1st to 7th ribs. attach directly to sternum anteriorly through their own costal cartilages

false (vertobrochondral) ribs
-8th to 10th ribs. joined to the cartilage of the rib just superior to them, indirect contact w sternum

floating (free) ribs
-11th to 12th ribs (sometimes 10th). end in the posterior abdominal musculature

Question 4

parts of typical ribs (3rd -9th)

Answer 4

• superior articular facet : articulates with the vertebra superior of rib number
• inferior articular facet : articulates with vertebra which numerically corresponds
• tubercle (articular part and non articular) : lump like enlargement. at junction of neck and body. articular part articulates with transverse process of vertebra (via synovial joint : allows increased joint mobility) . non articular part has fibrous attachment to the process via costotransverse ligament.
• angle : where rib begins to turn anterolaterally
• costal groove : protects intercostal nerve and vessels
• 10-12 ribs and 1st rib have only 1 facet
• 11 and 12 are short and have no necks/tubercles

Question 5

costal cartilages

Answer 5

prolong ribs anteriorly and contribute to the elasticity of the thoracic wall. Intercostal spaces separate the ribs from costal cartilages.

Question 6

Intercostal spaces

Answer 6

separate the ribs from costal cartilages.

Question 7

subcostal space

Answer 7

immediately below the 12th rib

Question 8

costovertebral joints

Answer 8

synovial plane joints that connect proximal end of ribs to vertebra.

-includes : body of vertebra superior to rib, invertebrate disc, head of rib (crest), body of vertebra of same number as rib

Question 9

costal facets (demifacets)

Answer 9

Where thoracic vertebra articulate with heads of rib

Question 10

costotransverse joint

Answer 10

Costal facets on transverse processes which articulate with tubercles of ribs.

Question 11

parts of sternum

Answer 11

• jugular notch : thick superior border of manubrium
• manubrium : lies at level of T3 and T4 vertebra
• manubriosternal joint (sternal angle) : connects manubrium and sternum
• xiphisternal joint : xiphoid and sternum connection
• xiphoid process : cartilaginous in young people, more or less ossified in adults over 40. in elderly, xiphoid process may fuse with sternal body
• clavicular notch
  sternum: longer and thinner than manubrium

Question 12

pump handle and bucket handle of ribs

Answer 12

Pump handle : movement of sternum (true ribs) anteriosuperiorly during forced respiration

bucket handle: movement of false ribs during forced respiration