Lecture 19: Bird Lungs

Question 1

Respiration occurs via _______________________.

Answer 1

Facilitated Diffusion

Question 2

Describe Insect respiration physiology:

Answer 2

• Don’t have circulatory systems

- Take air all the way to their cells via many tracheal systems so no cell is too far away

Question 3

Describe Fish respiration physiology:

Answer 3

• Gas exchange occurs across gills (evaginations)
• Ventilation is provided by gill movement
• Very effective counter-current exchange between water and blood
• Large surface for gas exchange
• Have to move huge amounts of water to get all of the O2 needed as O2 content is low

Question 4

Describe Amphibian respiration physiology:

Answer 4

• lungs are inverted bags with smaller SA

- Use positive pressure ventillation

Question 5

Describe 4 stroke ventilation in amphibians:

Answer 5

Inspo:
1. Nostrils open and buccal cavity expands
2. Nostrils close and the glotis opens, buccal cavity contracts and lungs expand
Expo:
3. Buccal cavity expands and lungs contract
4. Nostrils open and glotis closes, buccal cavity contracts

Question 6

Describe reptile respiratory physiology:

Answer 6

• Use negative pressure ventilation
• don’t have diaphragm
• rib movement provides the pressure change for air flow
• Have some folding in the lung

Question 7

How do crocodiles breath?

Answer 7

Have a diaphragmaticus which pulls of the liver and makes negative pressure in the thorax

Question 8

What is anatomical dead space?

Answer 8

The part of the airway that conducts air from the mouth to the bronchioles

Question 9

What is alveolar dead space?

Answer 9

Alveoli with no blood flowing through their surrounding capillaries

Question 10

Birds have ______________________ lungs and use ___________ for ventiliation but don’t have a ____________.

Answer 10

Calcified parabronchial lung
Negative pressure
Diaphragm

Question 11

What provides air movement in the bird lung?

Answer 11

Air sacs

Question 12

Describe the movement of air in the lungs of a bird:

Answer 12

1st inhalation: air enters the posterior air sacs
1st exhalation: air is pushed into the lungs
2nd inhalation: air enters the anterior sacs from the lung
2nd exhalation: air leaves the anterior sacs

Question 13

Why can birds breathe easier at lower pressures?

Answer 13

• Thin blood gas barrier

- Cross current

Question 14

How do birds condition their air?

Answer 14

Nasal turbinates cool expired air and recuperate some of the water that they add on during inspiration