Endotherms 3

Question 1

What are the features of birds respiratory system?

Answer 1

This is more complex than mammals as birds have faveolar lungs and air sacs with small chambers that open from a common space, sac in abdomen, neck and wings
The entire system is ventilated during breathing making it a one way system
The gas exchange is parabronchi with no residual volume
There was a higher O2 concentration than in mammals, with a more efficient system which serves the birds need for a higher O2 requirement and high altitude environments

Question 2

What is the process of inhalation and exhalation in birds?

Answer 2

The birds inhale air through their trachea to fill their posterior air sacs
This air is then moved into the lungs where it is later moved into the anterior air sacs where it can be exhaled through the trachea
This allows a one way flow of air through the lungs preventing residual volume from muddying the inhaled air

Question 3

What are the features of respiratory pigments?

Answer 3

These are diverse across the animal world
Binding must be reversible
They vary in oxygen-binding component with hemocyanin which is a copper based pigment in arthropods/molluscs
And hemoglodin which is a red iron based pigment found in almost all vertebrates

Question 4

What are the adaptations of bar-headed geese?

Answer 4

They have an increased affinity Hb and increased capillary density in the heart

Question 5

How is CO2 transported?

Answer 5

7% in solution in plasma
23% bound to amino acid groups of haemoglobin
70% transported in the blood as bicarbonate
The binding serves the purpose of maintaining the pH of the blood

Question 6

What are the features of diving mammals?

Answer 6

They store large amounts of O2 with 5% of this being stored in the lungs (to reduce buoyancy) and 70% being stored in the blood
As a result these organisms frequently have large blood volumes and large spleens, they also store O2 in muscles

Question 7

Where does positive linkage of the muscles and respiratory system occur?

Answer 7

In galloping mammals flexing of the spine can compress the thoracic cavity
In birds and bats inspiration occurs during or at end of upstroke of wing
In bats linkage of respiration and flight are essential