When you listen to a heartbeat you hear a LUB-DUB sound. What is the LUB sound?

• Closing of the AV valves

• Sound of blood rushing into Atria

• Sound of blood rushing into Ventricles

• Closing of Semilunar valves

CO2 is converted into carbonic acid in the cytoplasm of red blood cells by the enzyme...

• haemocyanin

• carbonic anhydrase

• oxyhaemoglobin

• oxyanhydrase

Which of the following is not a way to increase the efficiency of a respiratory system?

• increase the surface area available for diffusion of gases

• decrease the distance over which the gases must diffuse

• dry the system so gases don't have to diffuse through water

• all of these will increase efficiency

The majority of carbon dioxide is transported in the blood...

• Dissolved in the plasma

• Combined with haemoglobin to form carbaminohaemoglobin

• Bound to oxygen molecules

• Converted into H2CO3- ions

In a countercurrent exchange system the fluids flow the same way.

• True

• False

which of these is a passive process?

• Inspiration

• Expiration

• Forced expiration

• Forced inspiration

Match the definition- The volume of air breathed in and out in normal resting conditions.

• Tidal volume

• Vital capacity

• Residual volume

• Peak flow

Where does most gas exchange occur in insects?

• Spiracles

• Trachea

• Lungs

• Tracheoles

A circulatory system where blood travels through the heart once in a circuit

• Single

• Double

• Open

• Closed

What are the blood cells that transport oxygen?

• Fibrinogen

• Leukocytes

• Erythrocytes

• Phagocytes