Respiratory System Flashcards
Where does gas exchange occur in fish?
The gills
How does gas exchange occur in the gills of fish?
Water flows over the gill filaments, and oxygen diffuses from the water into the blood, while carbon dioxide diffuses from the blood into the water.
What is countercurrent flow, and why is it important in fish respiration?
Countercurrent flow refers to water and blood flowing in opposite directions across the gills, maximizing oxygen uptake by maintaining a concentration gradient along the entire length of the gill.
Where does gas exchange occur in amphibians
The skin and lungs, and as larvae gills
Why is the skin important for respiration in amphibians like frogs?
Amphibians can perform cutaneous respiration, where oxygen diffuses through their moist skin directly into the blood, making skin an essential respiratory organ.
Where does gas exchange occur in mammals?
Alveoli
What role do alveoli play in mammalian respiration?
Alveoli are small air sacs that provide a large surface area for gas exchange, allowing oxygen to diffuse into the blood and carbon dioxide to diffuse out.
What structure do insects use for gas exchange?
Tracheal system, consisting of a network of tubes (tracheae) that deliver oxygen directly to tissues.
How does gas exchange occur in the tracheal system of insects?
Oxygen diffuses from the external environment through spiracles into the tracheae, which deliver it directly to cells, while carbon dioxide is expelled through the same system.
Why is the tracheal system efficient for small, active insects?
It bypasses the need for a circulatory system to transport gases, allowing for direct oxygen delivery to tissues, which is efficient for their high activity levels.
How do earthworms, which lack specialized respiratory organs, perform gas exchange?
Earthworms rely on cutaneous respiration, where oxygen diffuses through their moist skin directly into their circulatory system.
What are the 5 requirements for gas exchange.
- Moist Surface
- Highly vascularised
- Thin surfaces
- concentration gradient
- SA : V
