exchange surfaces Flashcards
(40 cards)
What does the insect tracheal system provide?
The insect tracheal system provides a large surface area due to many branched tubes (tracheae and tracheoles).
What does the fish tracheal system provide?
The fish tracheal system provides a large surface area due to many filaments/lamellae/plates.
Why do organisms develop gills?
Organisms develop gills in habitats where oxygen is in short supply, as otherwise the rate of diffusion is too slow to meet their needs.
What happens to the lungs just after expiration?
Just after expiration, the lungs are less inflated, the diaphragm is domed, and the rib cage is in a lowered position.
Why is expiration considered passive?
Expiration is considered passive as it does not use muscle contraction; the rib cage falls due to gravity and the lungs recoil because they contain elastic tissue.
How should a participant measure vital capacity?
A participant should breathe in as deeply as possible and then force as much air out as possible.
How does increased surface area affect oxygen absorption?
Increased surface area increases oxygen absorption, which is useful in areas where oxygen concentration is low.
What is the method to dissect a fish’s gaseous exchange system?
To dissect a fish’s gaseous exchange system, remove the operculum to observe the gills, possibly using a rod/pencil in the buccal cavity to display lamellae.
What is the method to dissect an insect’s gaseous exchange system?
To dissect an insect, cut open the exoskeleton to view the tracheoles and stain them with methylene blue.
How do insect tracheae differ from mammal trachea?
Insects have multiple tracheae, while mammals have one; insect tracheae are supported by chitin, while mammal tracheas have cartilage.
Why is glucose easily transported in the bloodstream?
Glucose is easily transported in the bloodstream as it is water-soluble.
Why do single-celled organisms not need a specialized exchange surface?
Single-celled organisms have a large surface area to volume ratio, allowing diffusion to meet their needs without a specialized exchange surface.
What happens if bronchioles reduce in diameter?
It becomes hard to exhale if bronchioles reduce in diameter due to increased resistance to airflow.
What features make the lungs effective for gaseous exchange?
Features include many alveoli for large surface area, thin barrier, good blood supply, ventilation, and elastic tissue.
What happens to the volume of air in a spirometer over time?
The volume of air in a spirometer drops over time as oxygen is used in respiration and carbon dioxide is absorbed by soda lime.
Why do large, active organisms need a specialized surface for gaseous exchange?
Large active organisms have a higher demand for oxygen and a smaller surface area to volume ratio, making diffusion too slow.
How does having many alveoli improve gaseous exchange?
Having many alveoli increases the surface area for diffusion of oxygen and carbon dioxide.
What role does surfactant play in the alveoli?
Surfactant reduces surface tension in the alveoli, preventing them from collapsing.
How does ventilation maintain a steep diffusion gradient?
Ventilation increases the partial pressure of oxygen in the air sac and decreases the partial pressure of carbon dioxide.
What occurs during inspiration?
During inspiration, the diaphragm contracts and flattens, and the intercostal muscles contract to move the ribs up and out.
What is the function of goblet cells?
Goblet cells release mucus, which traps dust.
What do ciliated cells do?
Ciliated cells have cilia that waft mucus to the top of the trachea for swallowing.
What is the role of smooth muscle in the bronchus?
Smooth muscle fibers in the bronchus allow it to be constricted.
Why are blood capillaries and alveoli close together?
They are close together to provide a short path for diffusion and maintain a steep concentration gradient.
