Lecture 21 Flashcards
Define Gas Exchange
The intake of oxygen and the release of carbon dioxide.
In terms of concentration gradients, how do gases diffuse?
They diffuse DOWN their concentration gradient, meaning that they go from high concentration to low concentration.
Define Partial Pressure
The part oof the atmospheric pressure caused by one gas.
Compared to one another, does water hold more oxygen or air?
Air
Define Respiratory Surfaces
The sites where gas exchange take place.
Movement of gases occurs by _____.
Diffusion
When is diffusion fastest (in terms of thickness)?
Over a thin, wised surface.
What are the different types of exchange surfaces?
Epidermis-Trachea-Gills-Lungs. LET-G
What are the modes of ventilation?
Bucal Pump-Tidal Respiration-Flow Through Respiration.
What condition must be present in the exchange surfaces for gasses to dissolve?
Surfaces must be moist.
What does the earthworm lack?
A respiratory system.
Define Trachea
System of tubes and sacs that distribute air throughout the body.
What group is the trachea unique to?
Arthropoda.
What do tracheal systems not need?
They don’t need to be linked with the circulatory system.
In organisms with a trachea, how does the air enter?
It enters from a hole that is present on the side of their body.
What are some characteristics of gills?
LARGE, highly vascularized area where the water moves over.
What is the function of the Operculum?
It allows for water to flow over the gills.
Define Ventilation
The movement of the respiratory medium over the respiratory surface.
What mode of exchange is used by the gills to extract oxygen?
Countercurrent Exchange
How is oxygen delivered to the fish with gills?
The fish sucks in water, letting the water flow over the gills; the oxygen from the water diffuses over the blood vessels.
What type of structure are the lungs?
An internal respiratory structure.
What happens in the arteries next to the alveoli?
They gain oxygen; additionally, they are covered in capillaries.
What happens in the bucal pump mode of ventilation?
The air is forced over the gills and the lungs via positive pressure.
What are the two main steps in bucal ventilation?
Inspiration and Expiration.
