(17) Avian Respiratory Anatomy/Physiology Flashcards
(Unique Aspects of the Avian Respiratory System)
- Tracheal rings are complete or incomplete?
- Some birds have how many tracheas? example?
- Trachea is how much bigger than a comparably sized mammal?
- Anatomic dead space is how much bigger than that of comparably sized mammal?
- Is airflow at gas exchange level unidirectional or bidirectional? do they have alveoli?
- System can support sustained migratory flight at altitudes greater than what?
- complete
- two (penguins)
- 2.7x longer and 1.3x wider
- 4.5 larger
- unidirectional; no
- 20,000 feet
(Important Anatomic Aspects)
- Are lungs rigid or soft? Do they expand and contract?
- Do they have a diaphragm?
- What is air moved by (which function as what)?
- What do diverticula of the airsacs enter?
- What do both inspiration and expiration require?
- rigid, not really
- no
- Airsacs which function as bellows (there are 7 of them)
- many long bones
- muscle activity
Look at these differenes - and learn thm
(Comparative Physiology)
- What percentage of blood in avian lung is in contact with gas exchange? what in mammals?
- Is gas-blood barrier thicker or thinner?
- avian lungs have what types of receptors and what do they regulate?
- Efficiency of their system accomadates metabolic demands of what?
- 50-80% (vs 20% in mammals)
- thinner (about 50%)
- CO2, regulate intra-tidal regulation of respiration (mammals have mechano receptors in lungs instead)
- flight
What structure is used for vocalizations in birds? where is it located?
What happens to airflow when it reaches the level of the primary bronchi?
Why would a bird want its trachea to coil around a bunch?
- the syrinx (like the mammalian voice box); in the thoracic inlet, right at the point of bifurcation into the two bronchi
- it becomes turbulent
- to create a resonant chamber for vocalizations - for sex
How is the lung arranged relative to the rib?
So do birds have a pleural cavity like mammals do then?
- it’s up in it - right up on it - to the point that its shape contours to the ribs shape
- no
How many air sacs are there?
What are their names?
Which one doesn’t come in a pair?
What do they do?
- 7
- abdominal sac, caudal thoracic sac, cranical thoracic sac, interclavicular sac
- interclavicular sac
- they are thin membraned things that move air in and out of lungs like a bellows
AIR SACS ARE HUGE (relative to size of bird)
- Do the air sacs contain muscles?
How do they move?
- no
- thoracic muscles… muscles that are surrounding them but not a part of them
What is the order of Airway Branching?
(just a note…. the primary bronchi doesn’t branch off and then end - these things branch off it but it keeps going until it reaches the caudal air sac)
Anyway - what’s the order?
- There is active flow of air through the lung down to the level of the what? How does it move after that? Why does it stop here?
- Primary Bronchi
- Secondary Bronchi (median)
- Parabronchi (dorsal and ventral)
- Atri
- Infundibuli
- Air capillaris (site of gas exchange)
- the parabronchi; convection and diffusion; Airflow needs to be slow for oxygen going into blood to occur most efficiently
Give this figure a gander…. plus
- What do bronchi connect? what do they complete?
- dorsal and ventral secondary bronchi
- complete respiratory loop
- What two groups are the air sacs divided into?
- Is air flow separate between these two units? so will air ever meet between them? really?
- caudal group (caudal thoracic and abdominal)
- anterior (anterior and clavicular)
- yes, no, yes
(Airflow)
- When a bolus of air is inhaled where does it go (in first pass through)? Does it go into the lung? Is there any gas exchange on inhalation?
- When the bird exhales what happens?
- When the bird inhales the second time this cycle - what happens to the air now in the lung?
- When the bird exhales the second time what happens?
- What does this mean as far as interaction of air?
- the caudal air sacs; no; no
- The air that is in the caudal air sacs moves forward and doue to aerodynamic baffles that exist in the airway (like one way valves) - instead of going out bronchi goes into the secondary bronchi and into the lung
- air is forced out into the anterior group of air sacs
- The air goes through the body and out the trachea and into atmosphere
- there is no interaction of new air and old air in the lung - so you always have fresh o2 going through
This graph is just showing that O2 is the main thing providing tension in the lungs… also notice that this is more the case in the caudal air sacs
(Gas Exchange Unit)
- the whole unit consists of what?
- where is it?
- What is it shaped like?
- How are the blood flow and the flow of air situated?
- How does the blood flow out (what do the vessels look like)
- the secondary parabronchus –> atria –> infundibulum (air capillaries not visible)
- the lung
- hexagonal
- they cross each other (a 90 degree angle)
- they are branched in the bronchi but then join into one as they leave the bronchi (pooling all of the oxygen)
Look at this image - it is a good one (is on ipad)
Look at and understand the lesser than greater thans
What is the big point here?
in the mammalian lung - the oxygn tension, if it goes into the systemic blood is less than the expired O2, this is not the case with birds
another way of looking at the same concept (also on your ipad)
