Thoracic cavity

Question 1

Ribs

Answer 1

12 pairs:

• 1⇒7: true ribs
• 8⇒10: false ribs, common cartilage connection
• 11⇒12: flating ribs, no cartilage
• have head, neck, body and tubercle

Question 2

Vertebrae

Answer 2

• 7 cervical
• 12 thoracic vertebrae
  
  • costal fovea
• 5 lumbar vertebrae
  
  • costal process
  • accessory process
  • mammilary process
• 5 sacral vertebrae
• 4 Coccyx

Question 3

Inervertebral disk

Answer 3

• annulus fibrosus: outer fibrous part, ring of fibrocartilage
• nucleus pulposus: central gelatinous soft fibrocartilage

Question 4

Ligaments of vertebrae

Answer 4

• anterior longitudinal ligament
• posterior longitudinal ligament
• ligamenta flava
• interspinous ligaments
• suprasinous ligaments
• intertransverse ligament

Question 5

Joints of thoracic cage

Answer 5

• joint of head of ribs
• costotransverse joints
• costochondral joint
• interchondral joint
• sternocostal joint

Question 6

External intercostal muscles

Answer 6

• 11 pairs
• tubercle of ribs posteriorly ⇒ costochondral junction anteriorly
• fibers from up, lat ⇒ down, med
• function: contract during inspiration, elevate ribs

Question 7

Internal Intercostal muscles + innermost intercostal

Answer 7

• 11 pairs
• fibers from superioanteriorly ⇒ down
• sternum ⇒ angle of ribs posteriorly
• function: depresses ribs during expiration, elevates ribs during inspiration

Question 8

Subcostal muscles

Answer 8

• in posterior lateral thoracic wall
• extend across more than 1 IC space
• function: expiration

Question 9

Nerves of thoracic wall

Answer 9

12 pairs of thoracic spinal nerves ⇒ anterior and posterior ramus

• Posterior rami ⇒ medial and lateral branch ⇒ muscles of the back
• Anterior rami ⇒ run along extent of intercostal spaces⇒ give cutaneous branches

Question 10

Vasculature of thoracic wall

Answer 10

• from thoracic aorta, subclavian artery an axillary artery
• each IC space has: large posterior IC artery + small pair of anterior IC arteries
• veins: supreme IC veins (⇒ brachiocephalic vein) + superior IC veins (⇒ azygos/hemiazygos)

Question 11

Parts of Diaphragm

Answer 11

1. muscular part
   - sternal
   - costal
   - lumbar
2. tendinous part

Question 12

Caval opening of diaphragm

Answer 12

T8/T9

IVC + right phrenic nerve

Question 13

Esophageal hiatus of diaphragm

Answer 13

T10

esophagus + left and right vagal trunks + left gastric vein

Question 14

Aortic hiatus of diaphragm

Answer 14

T12

aorta + thoracic duct

Question 15

Sternocostal triangle of diaphragm

Answer 15

superior epigastric vessel

Question 16

Intermediate hiatus of diaphragm

Answer 16

sympathtic trunk + azygos + hemiazygos vein + greater and lesser splanchnic nerves

Question 17

Arterial supply of Diaphragm

Answer 17

superior phrenic artery (thoracic aorta)
inferior phrenic artery (abdominal aorta)
musculophrenic + pericardiophrenic arteies (internal thoracic artery)

Question 18

Innervation of diaphragm

Answer 18

Phrenic nerve (C3-C5)

Question 19

Position of diaphragm

Answer 19

Midposition: right dome reaches 4th IC space and left dome is in 5th IC space
Maximal Expiration: right dome upper margin of 4th rib, left dome in 4th IC space
Maximal Inspiration: right dome to 6th rib, left dome to 6th IC space