Osteology of Thoracic Cage

Question 1

Learn the structures that lie behind the manubrium of the sternum

Answer 1

Structures in the superior mediastinum:

• Thymus
• Brachiocephalic veins and SVC
• Aortic Arch
• Trachea
• oesophagus
• Phrenic nerve
• vagus and left recurrent laryngeal nerves
• Sympathetic trunks

Question 2

What structures lie behind the sternal angle?

Answer 2

• Azygos vein enters the SVC
• Ascending aorta becomes the aortic arch
• the arch then becomes the descending aorta
• ligamentum arteriosum lies just inferior to the aortic arch

Question 3

What structure lies in the midline of the neck anteriorly

Answer 3

Trachea

Question 4

Where is the mid clavicular line?

Answer 4

halfway between the sternoclavicular and the acromioclavicular joints, both of which are easily palpable

Question 5

where is the mid axillary line?

Answer 5

lies mid way between the axillary folds

Question 6

where is the mid scapula line

Answer 6

drawn inferiorly from the inferior angle

Question 7

What does parasternal mean?

Answer 7

either side of the sternum

Question 8

What does praecordal mean?

Answer 8

refers to the anterior chest wall

Question 9

Where is the jugular/sternal notch

Answer 9

superior border of the manubrium. Lies betweenn the intersections of the right and left sternocleidomastoid muscles and lies at the level of the intervertebral disc between T2 and T3

Question 10

What costal cartilage meets the sternum at the sternal angle

Answer 10

2nd

Question 11

Where is the xiphisternal joint

Answer 11

T8 and T9

Question 12

name the muscles that lie on either side of the trachea

Answer 12

Infrahyoid, strap muscles: sternohyoid, omonhyoid, thyrohyoid. The sternocleidomastoid muscles are slightly lateral

Question 13

What vessels lie on either side of the trachea?

Answer 13

• Common carotid arteries

- Internal jugular veins

Question 14

What other structures pass through the thoracic inlet?

Answer 14

• trachea
• common carotid arteries and internal jugular veins
• oesphagus
• phrenic, vagus and left recurrent laryngeal nerves
• sympathetic trunks
• subclavian vessels
• brachial plexus

Question 15

Where is the central tendon of the diaphragm in relation to the ribs?

Answer 15

The domes of the diaphragm move with respiration and posture. The central tendon moves a little bit as well, therefore it has a slightly variable position level with T8/9 vertebrae and the 7th ribs/costal cartilages anteriorly

Question 16

Are there any abdominal viscera within the thoracic cage

Answer 16

As the diaphragm bulges superiorly into the thoracic cage, the liver, spleen, fundus of stomach, although within the abdominal cavity, lie within the thoracic cage. The kidneys could be include too as they are related to the lower ribs.

Question 17

How many cervical, thoracic and lumbar vertebrae are there?

Answer 17

C = 7
T = 12
L = 5

Question 18

are there Demi facets present of all thoracic vertebrae?

Answer 18

Only on the vertebrae that articulate with the typical ribs, so T1, 10, 11 and 12 do not have demi-facets