Ch 103 - Lungs Flashcards
How many sternebrae does a dog have?
9
List the muscle that cover the thoracic wall from internal to external
- Serratus dorsalis and ventralis
- Scalenus
- External abdominal oblique
- Latissimus dorsi
- pectoralis
- Cutaneous trunci
List the lung lobes
Left:
- Left cranial (subdivided into cranial and caudal)
- Left caudal
Right:
- Cranial
- Middle
- Caudal
- Accessory
Where are the pulmonary arteries and vein located in relation to the associated bronchus?
- Artery: craniodorsal
- Vein - Caudoventral
What muscles can be engaged to aid inspiration and expiration?
Inspiration:
- external intercostal
- sternocleidomastoid
- scalenus
- serratus ventralis
Expiration:
- Internal intercostals
- Abdominal rectus
What can alter lung complicance?
- Fibrosis
- Oedema
What cells produce surfactant?
What is its function?
- Alveolar type II cells
- Indirectly increases lung compliance by reducing surface tension
- Prevents collapse of small alveoli
What structures contribute to inspiratory resistance and expiratory resistance?
Inspiratory:
- Nares 79%
- Small airways 15%
- Larynx 6%
Expiratory:
- Nasal 74%
- Laryngeal 3%
- Small airways 23%
What controls ventilation?
- Chemoreceptors in respiratory centre in medulla
- Peripheral chemoreceptors in carotid and aortic bodies
- Stretch receptors in the airway and lung parenchyma stop inspiration
What is hypoxic ventilation drive?
An increase in ventilation if PaO2 is below 60mmHg
What is Ficks law?
The rate of transfer of a gas through a sheet of tissue is proportional to the surface area available for diffusion, diffusion coefficient of the gas, difference in gas partial pressures and inversely proportional to the tissue thickness
How does the diffusion coefficient compare between CO2 and O2
CO2 is 20x greater
What can cause the oxygen dissociated curve to shift to the right?
- Increased temp, PCO2, 2,3-DPG
- Decreased pH
What can cause a high V/Q and a low V/Q
- High V/Q - PTE
- Low V/Q - atelectasis, pneumonia, severe pulm oedema
What are common post-op problems to monitor for after a thoracotomy?
- Hypotension
- Hypothermia
- Hypoventilation
- Electrolyte imbalance
- Shock