Thorax

Question 1

what muscular structure helps as a landmark at the level of the 5th rib?

Answer 1

Scalenus muscle - division between muscular to tendinous portion of the muscle

Question 2

The latissimus dorsi muscle attaches where?

Answer 2

Proximal humerus

Question 3

Describe muscular layers during approach to intercostal thoracotomy

Answer 3

Cutaneous trunci
Latissimus dorsi
Superficial / Deep pectoralis
Serratus ventralis / dorsalis
Scalenus
external intercostal
Internal intercostal
+/- Transverse thoracis muscle

Question 4

Intercostal approach for treatment of a persistent right aortic arch is best on which laterality?

Answer 4

left side
(best visuailzation of esophagus and ligamentum arteriosum)

Question 5

What structures limit the dorsal and ventral extent of intercostal thoracotomy incision?

Answer 5

Dorsally: epaxial musculature, intercostal artery root

Ventrally: internal thoracic artery

Question 6

Where is a common location for development of thoracic wall tumors?

Answer 6

Costochondral junction

Question 7

What artery provides most blood supply to the dorsolateral thorax?

Answer 7

Thoracodorsal artery

Question 8

Which ribs articulate with the sternum?

Answer 8

1-9

Question 9

What muscle attaches to the manubrium cranially?

Answer 9

Sternocephalicus

Question 10

What muscle attaches to the xiphoid?

Answer 10

diaphragm

Question 11

The rectus abdominis muscles attach cranially to?

Answer 11

fascia of the deep pectorals

Question 12

The internal thoracic arteries are branches from which

Answer 12

left and right subclavian aa.

Question 13

What is the normal volume of pleural fluid in dogs/cats?

Answer 13

Dogs 0.1mL/kg
Cats 0.3mL/kg

Question 14

What structures are contained within the mediastinum?

Answer 14

Heart
Great vessels
Trachea
esophagus
Thoracic duct / lymphatics
Thymus
Internal thoracic vessels
nerves: phrenic, vagal, recurrent laryngeal, cardiosympathetic, cardiovagal

Question 15

Plica vena cava

Answer 15

Branch/reflection of mediastinal pleura that connects to caudal vena cava
Forms mediastinal recess - dorsal opening provides access to accessory lung lobe

Question 16

Dorsal thoracic lymphatic center (aortic thoracic nodes) are present in what % of dogs?

Answer 16

25%

Question 17

Describe the relationship of the thoracic duct relative to the aorta in dogs/cats?

Answer 17

Dogs: right dorsolateral to aorta cranially and caudally

Cats: right dorsolateral to aorta cranially, left dorsolateral to aorta caudally

Question 18

At what age does the thymus involute?

Answer 18

4-5 months

Question 19

Blood supply to thymus

Answer 19

internal thoracic arteries
+/- brachiocephalic aa. or left subclavian aa.

Question 20

Functional residual capacity

Answer 20

Volume of air remaining within the lung at the end of exhalation
~45ml/kg

Question 21

Primary function of the thymus

Answer 21

Maturation and selection of T cells

Question 22

Intercostal veins drain into which veins?

Answer 22

Azygous vein
Costcocervical vein (1st intercostal vein only)

Question 23

The hilus of the lungs is located at which intercostal space?

Answer 23

Between 4th to 5th intercostal spaces

Question 24

What intercostal thoracotomy provides best access to the right middle lung lobe?

Answer 24

right 5th intercostal space

Answer 25

Cranial: 4th to 5th intercostal space

Caudal: 5th to 6th intercostal space