Ventilation Flashcards
How is surface area to volume ratio calculated?
Surface area/Volume
Which muscles are involved in human ventilation?
External and internal intercostal muscles; diaphragm
Describe what happens when a human inhales?
External intercostal muscles contract, moves ribs up
Diaphragm contracts, flattens
Pressure in thoracic cavity decreases
Volume of lungs increases
Movement of air into the lungs
What is vital capacity?
Maximum volume that can be exhaled after a maximum inhalation (dm3)
What does a spirometer measure?
The volume and function of the lungs
Describe the function of cartilage in the trachea?
Supported by C-shaped cartilage to keep it open, so that air can flow in and out the lungs
What is a concentration gradient?
The difference between the concentration of a substance in two different areas; the larger the concentration gradient, the faster the substance diffuses towards the lower concentration
How do insects such as crickets exchange gases?
Air moves into the tracheae, which divides until they reach the cells as tracheoles
Diffusion occurs between body cells and the tracheoles, exchanging gases via the tracheal fluid
How do fish ventilate the gills?
Increase and decrease in the volume of the buccal cavity and opening and closing of the operculum
Describe the countercurrent system in fish
Blood in capillaries flows in the opposite direction to the water flowing over them
This maximises the gas exchange compared with the parallel system
What are the adaptations of root hair cells to maximise water absorption?
Root hair protrusion greatly increases surface area
List 3 features of gas exchange surfaces
Increased surface area
Thin for short diffusion pathway
Good concentration gradient due to rich blood supply and ventilation
What is the function of the elastic tissue in the bronchi and bronchioles?
Allows the lungs to recoil back into shape after expanding
