Thorax

Question 1

Inferior thoracic aperture

Answer 1

Thoracic outlet:is bounded by T12, the 11th and 12th pairs of ribs, costal cartilages of ribs 7-10 and the xiphisternal joint.
Closed by the diaphragm separating the thorax from the abdomen

3 openings: Esophageal Hiatus, Aortic Hiatus, Inferior Vena Caval Hiatus

Question 2

Superior thoracic aperture

Answer 2

Thoracic inlet: bounded by T1, the 1st ribs plus their cartilages and the superior border of the manubrium.
Structures passing through the STA include the trachea, esophagus, nerves and blood vessels that either supply or drain the head, neck and upper extremities

Question 3

Thoracic cage movements: Vertical diameter

Answer 3

Increases during inspiration- as the diaphragm descends; expiration causes the ascent of the diaphragm, which returns the vertical diameter to its original size

Question 4

Thoracic cage movements: Transverse diameter

Answer 4

Increases slightly when the intercostal muscles contract (bucket handle motion)

Question 5

Thoracic cage movements: Anteroposterior diameter

Answer 5

Movement of ribs 2-6 at the costovertebral joints about an axis going through the neck of the ribs causing the sternal ends of the ribs to rise (pump handle motion)

Question 6

Posterior wall blood supply

Answer 6

supplied by posterior intercostals which are branches of the aorta and costocervical trunk

Question 7

Anterior wall blood supply

Answer 7

supplied by anterior intercostals which are branches of the internal thoracic and musculo-phrenic arteries. Also supreme thoracic artery

Question 8

Intercostal veins

Answer 8

Generally runs opposite of the arterial supply and drain into the azygos and hemiazygos veins. They are part of the systemic circulation

Question 9

Nerve supply

Answer 9

Intercostal muscles are innervated by ventral rami of thoracic nerves (intercostal nerves)

Question 10

Dermatome: Clavicles and jugular notch

Answer 10

C4 (Supraclaviculars)

Question 11

Dermatome: Sternal angle

Answer 11

T2

Question 12

Dermatomes: Nipples

Answer 12

T4

Question 13

Superior mediastinum

Answer 13

superior to the manubriosternal junction (sternal angle) and T4-T5 IVD but inferior to the thoracic inlet.

Question 14

Inferior mediastinum

Answer 14

area inferior to the sternal angle but superior to the diaphragm which is further divided into:
Anterior Mediastinum
Middle Mediastinum
Posterior Mediastinum

Question 15

Boundaries of the thoracic mediastinum

Answer 15

Lateral -two pleural sacs (lungs).
Superior - superior thoracic aperture.
Inferior- diaphragm
Anterior- sternum and costal cartilage
Posterior - thoracic vertebral bodies

Question 16

Superior mediastinum contains:

Answer 16

Aortic arch 
brachiocephalic trunk 
left common carotid a. 
left subclavian a. 
Superior vena cava 
brachiocephalic vv. (L & R)                                 
Thymus 
Trachea
Esophagus 
Vagus and Phrenic n.   
recurrent laryngeal n.                                
Thoracic duct

Question 17

Anterior mediastinum

Answer 17

Boundaries
Sternum anteriorly
Pericardium posteriorly
Contents:
Loose connective tissue
Fat
Lymphatic vessels and their nodes
Branches of internal thoracic vessels
Lower portion of thymus (if young)

Question 18

Middle mediastinum

Answer 18

beneath sternal angle, between anterior/ posterior mediastinum and above diaphragm

Pericardium
Heart*
Ascending aorta
Pulmonary arterial trunk
Right and left superior and inferior pulmonary veins
Inferior portion of superior vena cava
The attaching portion of the azygos vein to the SVC
Right and left phrenic nerves