Cardio-respiratory System Flashcards
How do animals keep their respiratory system moist?
Remain in moist areas
Have covered or fully internal structures
What did aerial gas exchange evolve from?
The lung fish
What is a positive pressure system?
Where air is forced into the lungs to expand them
What pressure system do most reptiles have?
Positive
What do turtles and tortoises do?
Change the volume of the whole thorax due to limitations by their shell
What pressure system do crocodiles use?
A negative pressure system
Describe the pressure system in the crocodile
Two cavities: thoracic and abdominal cavity separated by the hepatic septum
The hepatic septum pulls the abdominal cavity back drawing air into the lung due to a lower pressure
What pressure system do humans have?
A negative pressure system
Describe the pressure system in humans:
Diaphragm contracts pulling air in, thoracic cavity expands
Diaphragm and intercostal muscles relax allowing us to breath out
How are the lungs in an elephant able to withstand a lot of pressure when in an aquatic environment?
Dense connective tissue supports the lung in order to withstand pressure difference
What are bird lungs like?
They’re small and rigid with no alveoli, instead they have vascularised tubes called PARABRONCHI
Parabronchi connected to air sacs which penetrate everywhere
What is the process called that air passes in birds?
Cross current manner
Not counter current
