Kapitel 103 - Lungs

Question 1

The right lung is divided into four distinct lobes. Which one is located medial to the plica
vena cava?

Answer 1

Accessory Lobe

Page 1983 > The accessory lobe passes dorsal to the caudal vena cava and is located
medial to the plica vena cava .
Miller 5th page 407 > The plica vena cava is a separate fold of the right caudal mediastinal
pleura, which projects dorsally from the level of the sternum to surround the caudal vena
cava and right phrenic nerve approximately one-third of the distance between the sternum
and the vertebral column.

Question 2

Which statements are true?
1. A high V/Q can be induced by severe pulmonary edema.
2. The ventilatory response to CO 2 of peripheral receptors is usually more

Answer 2

1: false 2: true

Statement 1 page 1987 > To achieve an adequate exchange of oxygen between the alveoli
and the arterial blood in the capillaries, flow of blood (Q) and ventilation of the alveoli (V)
have to match, in a ratio (V/Q) equal to 1. Any changes in this ratio will induce either a high
or a low V/Q. High V/Q is induced commonly by pulmonary thromboembolism, whereas a
low V/Q is induced by atelectasia, pneumonia, and severe pulmonary edema.
Statement 2 page 1985 > CO2 also stimulates peripheral receptors in carotid and aortic
bodies. The resulting ventilatory response is usually more rapid but of smaller magnitude
than that seen with stimulation of central receptors.

Question 3

Which surgical approach will you use when you plan to do surgery on a dog suspected of
pulmonary bullae or blebs?

Answer 3

Median Sternotomy

Question 4

What are the most affected lung lobes regarding lung lobe torsion in large dogs with deep
and narrow chests?

Answer 4

left cranial lobe and right middle lobe

Question 5

What percentage of cats with primary lung lobe tumors do have metastasis to the digits?

Answer 5

17,9%

Question 6

Write down Fick’s law

Answer 6

Ficks law states that the rate of transfer of a gas through a sheet of tissue (1) is
* proportional to:
- surface area available for diffusion (1)
- diffusion coefficient of the gas (1)
- difference in gas partial pressure between sides (1)
* inversely proportional to:
- tissue thickness (distance gas must travel) (1)

Question 7

Hypoxemia is defined by an arterial oxygen saturation less than 90%. List five (5) causes
of hypoxemia.

Answer 7

1 - hypoventilation
2 - low fraction of inspired oxygen
3 - diffusion impairment (chronic emphysema, pulmonary interstitial fibrosis)
4 - ventilation-perfusion (V/Q) mismatch
5 - shunting

Question 8

What is the difference between cysts, bullae and blebs?

Answer 8

Cysts → thin-walled cavity within the lung parenchyma, covered by a respiratory epithelium.
Can be fluid filled.

Bullae → thin-walled large are spaces/cavity within the lung parenchyma, without epithelial
lining, but fibrous walls

Blebs → small accumulations of air between parenchyma and visceral pleura, without
epithelial lining, do have fibrous walls

Question 9

When planning to suture a lacerated lung lobe, which suture pattern and material would
you use?

Answer 9

→ a mattress pattern (interrupted Lembert mattress suture pattern or hemostatic mattress
suture in combination with a simple continuous suture)
→ 4-0 or 5-0 absorbable suture wire