Respiration and Circulation (Ch 39) Key Concepts. Flashcards
What are the dis/advantages of using only diffusion as a respiratory system?
Advantage: With a large enough surface area, diffusion is an extremely effective way to exchange gases and other substances over short distances between two compartments.
Disadvantage: generally ineffective over long distances
What are 4 features that all exchange surfaces must have?
1) Have a large surface area relative to the volume of the organism.
2) They are thin, for short diffusion pathway.
3) They have a moist surface where gases can dissolve first before they diffuse in or out.
4) They are able to maintain the diffusion gradient down which the gases can diffuse.
What are the dis/advantages off using gills for breathing?
Advantages: Gills have a large surface area and are extremely thin. The surfaces are only one to two cell layers thick, providing a diffusion distance of as little as 1-2 micrometers.
Disadvantage: Gills often rely on the natural motions of the water to move water past the gills.
Describe how countercurrent exchange work on gills.
Countercurrent exchange extract nearly all the O2 in the water that passes through them, where all the fluids such as O2, CO2, or heat exchange properties efficiently.
What are the dis/advantages of tracheal system for breathing?
Advantage: Animals that uses the tracheal system are able to increase their uptake of O2 and achieve higher rates of metabolism.
Disadvantage: Does not work under water. Water has higher viscosity and higher density than air.
What are the dis/advantages of lungs for breathing?
Advantage: Lungs have an enormous surface area and a short diffusion distance for gas exchange.
Disadvantage: Lungs of mammals supply O2 quickly enough to support high metabolic rates.
How does negative pressure breathing work?
Mammals and reptiles expand their thoracic cavity to draw air inside their lung on inhalation. The expansion of the lungs causes the air pressure inside the lungs to become lower than the air pressure outside the lungs. The resulting negative pressure draws air into the lungs.
How is our breathing monitored by the autonomic nervous system?
Involuntary breathing depends on chemoreceptors located within the brainstorm and in sensory structures called carotid and aortic bodies.
What is the most important factor regarding the control of breathing?
The amount of CO2 in the blood.
How is oxygen carried throughout your body? How is CO2 carried?
By the hemoglobin and circulatory system; as a bicarbonate
