tracheal system of insects

(5 facts)

1.Direct and efficient system

2.Air enters and leaves the tracheal system through valvelike openings (spiracles)

3.Tracheal channels narrow to fluid-filled tracheoles 1 mm in diameter embedded in tissues

4.Some insects ventilate the tracheal system with body movements

5.Independent of the hemolymph (circulatory fluid) that has no direct role in respiration 

How does countercurrent flow increase the efficiency of fish gills?

  Blood flow is opposite the flow of water to provide the maximum extraction of oxygen

Parabronchi

-          air sacs:

-          positive pressure breathers:

(Amphibians)

1. Draw air into their mouth thru external nares

2. Close the nostrils and raise the floor of the mouth which drives air into the lungs

-          negative pressure ventilation:

ventilate lungs by sucking air in by expanding the thoracic cavity;

Increase in volume causes air pressure in thoracic cavity to fall

below atmospheric pressure;

Air rushes into passages passively

-          diaphragm:

1.occurring only in mammals

2. a dome shaped, muscular partition which separates the thoracic and abdominal cavities; 

3.moves down during inspiration 

4. moves up during expiration

Why are the respiratory systems of birds so efficient?

b/c of air sacs, recieve oxygen while inspirating AND expirating

Which respiratory pigment is the most common in the animal kingdom?

inspiration

(4 facts)

ribcage moves up and out and the diaphragm moves down 

expiration

(4 facts)

ribcage moves down and inward and the diaphragm up