Avian respiratory and physiology

Question 1

Where does the respiratory system begin?

Answer 1

Nares–located at the flesh portion of the beak

Exact location varies with species

Question 2

T/F: The nares are a good location for sampling

Answer 2

TRUE

(Nasal flushes)

Question 3

What is the area being swabbed? What’s its purpose?

Answer 3

Choana

Connects oral cavity with respiratory system

(Palatine fissure)

Question 4

T/F: Birds do not have a soft palate

Answer 4

TRUE

Question 5

What is the best location for sampling the respiratory system?

Answer 5

Choana

Question 6

Where is the opening of the trachea? Where is the epiglottis?

Answer 6

Trachea opens at the base of the tongue

Birds do not have an epiglottis!

Question 7

T/F: Birds have complete tracheal rings

Answer 7

TRUE

Question 8

Label the picture:

Answer 8

Question 9

T/F: The crop lies to the left of the trachea

Answer 9

FALSE–it is on the right!

Question 10

Is the trachea a good location to take a sample?

Answer 10

Yes!

Question 11

What (where) should you always check if a bird presents with a vocalization problem?

Answer 11

Trachea! Tracheal endoscopy–bifurcation of the trachea is an easy location for foreign bodies to get lodged

Question 12

What is the syrinx? What does it do?

Answer 12

Voicebox of the bird

Membranes move as air moves through–pitch changes depending on location of membrane movement

Question 13

What do air capillaries arise from?

Answer 13

Parabronchi

Question 14

Label the bronchi:

Answer 14

Question 15

T/F: Avian lungs are very rigid with very little elasticity. They are tightly adhered to the ribs.

Answer 15

TRUE

Question 16

What kind of pattern will the parabronchi resemble on a radiograph?

Answer 16

Reticular pattern (honeycomb-like)

Question 17

Label the air sacs:

Answer 17

Question 18

T/F: Air sac membranes are an opaque white color

Answer 18

FALSE–they are transparent

Question 19

What make up the anterior air sacs? Posterior?

Answer 19

• Anterior
  
  • Cervical air sacs
  • Interclavicular air sacs
  • Anterior thoracic air sacs
• Posterior
  
  • Caudal thoracic air sacs
  • Abdominal air sacs

Question 20

How much do avian lungs expand? What about the diaphragm?

Answer 20

They don’t!

And birds don’t have a diaphragm, dummy

Question 21

What is the direction of air flow through the lungs?

Answer 21

Unidirectional

This is the key to the avian respiratory system!

Question 22

What provides the mechanical force for inspiratory and expiratory movements?

Answer 22

Movement of sternum and ribs

NOT a diaphragm like in gross humans

Question 23

Explain airflow through the lungs during inspiration and expiration

Answer 23

• Inspiration
  
  • Most air goes to posterior air sacs but some passes through the lungs
  • Posterior and anterior air sacs expand
  • Gas exchange occurs as air passes through lungs
• Expiration
  
  • Posterior and anterior air sacs contract
  • Gas exchange occurs as air passes through lungs
• There is no mixing of “old” and fresh air
• There is no functional residual volume, air must be constantly flowing

Question 24

T/F: Like mammals under anesthesia, if birds stop breathing you have some ‘breathing room’ (LOL) before having to breathe for them

Answer 24

FALSE–DO NOT WAIT, YOU MUST DELIVER OXYGEN IMMEDIATELY

Birds must have a CONSTANT supply of air

Question 25

What are the 7 components of the typical bird anesthesia set up?

Answer 25

1. Isoflurane
2. Vaporizer
3. Oxygen tank
4. Regulator
5. Inlet and outlet hoses
6. Masks
7. “Vapor wand”

Question 26

What percentage does Cruz recommend starting at during mask anesthesia?

What should you always be sure to avoid?

Answer 26

Full dose (5% isoflurane), then reduce progressively as the bird becomes anesthetized

Be sure not to block the nares during induction

Question 27

What are some pre-anesthetic considerations?

Answer 27

Same as for mammals:

Fasting (might be very short for small birds), hydration status, CBC & chemistry, analgesics

Question 28

What is important to remember about avian tracheal rings and trach tubes?

Answer 28

Avian complete tracheal rings do not distend!

Do not used a cuff tube (or if you have nothing else, just DO NOT inflate the cuff)

Question 29

How should the tracheal tube be fitted and secured?

Answer 29

• Slight snug fit to prevent aspiration of saliva or secretions but not too tight
• If too tight–>pressure necrosis
• Don’t need to go too far in
  
  • (That’s definitely NOT what she said)
• Be aware of vagal stimulation!
• Tape tube to lower mandible

Question 30

T/F: Even a catheter can be used as a tracheal tube for teeny tiny birdies

Answer 30

TRUE

Question 31

Does isoflurane change between species?

Answer 31

Nope! Regardless of the species, isoflurane is usually kept between 2-3%

Question 32

Why isn’t sevoflurane usually used in avian anesthesia?

Answer 32

Much more expensive than isoflurane and birds will wake up immediately (not practical)

Question 33

What monitoring equipment should be used during anesthesia?

Answer 33

Heat source

Pulse ox

Temperature probe

Esophageal stethoscope

Doppler

Question 34

T/F: If an anesthetized bird is breathing there is no need to provide PPV, but as soon as it stops it must be provided immediately

Answer 34

FALSE

Even if the bird is breathing normally on its own during anesthesia, provide (gentle) positive pressure ventilation 2-4 times per minute

Question 35

What should be done during recovery after anesthesia?

Answer 35

Stop the isoflurane and continue with oxygen only for a few minutes

Hold the bird upright

Remove trach tube once bird has fairly recovered

Question 36

T/F: Butorphanol prolongs avian recovery following anesthesia

Answer 36

TRUE

Question 37

What are 3 reasons for air sac canulation?

Answer 37

Emergency (severe dyspnea)

Programed surgery on oral cavity or enucleation

Diagnostic procedure