7/04 pt 2 Flashcards
(26 cards)
What is an animal?
Eukaryotic cell, multicellular, complex organs, heterotrophic by ingestion, embryonic development, most are motile, courtship and parent care, social behaviour
What are the different respiratory media compared?
Water and air
What are the differences between air and water as respiratory media?
- O2 content
- Diffusion rate
- Density of medium
- Viscosity of medium
How much more viscous is water compared to air?
50 times more viscous
What is the solubility of O2 in water described as?
Low solubility in water (polar)
What happens to dissolved O2 as water temperature increases?
Dissolved O2 decreases
What happens to dissolved O2 as solute concentration increases?
Dissolved O2 decreases
What is the principle that determines the concentration of gas?
Solubility
What does diffusion depend on?
- Partial pressure gradient
- Membrane properties
- Permeability
- Surface area/volume
- Thickness
What happens to surface area (SA) to volume (V) ratio as organisms increase in volume?
SA does not increase at the same rate
What is the consequence of larger body size on gas exchange?
Less SA for gas exchange, diffusion becomes ineffective and insufficient
What are the different gas exchange structures found in organisms?
- Lungs
- Internal gills
- Tracheae
- Body surface
What factors influence the diversity of gas exchange structures?
- Respiratory media used
- Habitat occupied
- Body size (SA/volume)
- Metabolic capacity and lifestyle
What are the basic forms in the design of gas exchange structures?
- Evagination
- Invagination
- Compartmentalisation
- Thin partitions
- Vascularisation
What are the two types of circulatory systems?
- Open circulatory system
- Closed circulatory system
What is an open circulatory system?
Hemolymph surrounding body tissue as the circulatory fluid
What is a closed circulatory system?
Interstitial fluid distinct from blood acting as the circulatory fluid
What is the tracheal system of insects?
Extensive network of thin-walled tubes of chitin
What are spiracles in the tracheal system?
Valve-like holes through which air enters
How does air enter the tracheal system?
Muscular movement of body draws air into the spiracles
What are the features of gills in aquatic organisms?
- Large outgrowths protected by operculum
- Supported by gill arches
- Plate-like extensions called gill filaments
- Filaments covered by lamellae
What is countercurrent gas exchange?
Blood flows in the opposite direction to external water flow within each lamella
What are the characteristics of mammalian lungs?
- Infoldings of the body surface
- Gas exchange occurs in thin-walled alveoli
- Two-way flow system
What is unique about avian lungs?
Unidirectional flow system with air sacs
