Transport in animals Flashcards
What is the transport medium in open circulatory systems?
Haemolymph
What is the body cavity in open circulatory systems called?
Haemocoel
Why do animals require transport systems?
Rate of diffusion too low
High metabolic rates
Low SA:V ratios
Molecules (e.g. enzymes and hormones) need to be transported to specific tissues
What are internal transport systems for?
To transport nutrients and oxygen around the body
What are some examples of organisms with open circulatory systems?
Some invertebrates, such as arthropods (including insects) and molluscs
What are some examples of organisms with closed circulatory systems?
All vertebrates and many invertebrates (e.g annelid worms, cephalopods)
What is the transport medium in closed circulatory systems?
Blood
What are some examples of organisms that have single circulatory systems? (blood passes through heart once per circulation)
Fish, annelid worms
What are some organisms that have a double circulatory system? (Blood pumped to lungs and returns to heart carrying oxygen, then to body tissues before returning to heart
Birds and mammals
What is circulation to the lungs called?
Pulmonary circulation
What is circulation to the respiring tissues called?
Systemic circulation
What are the advantages of a closed double circulatory system?
Blood pressure is maintained
Oxygenated and deoxygenated blood does not mix
Lower volumes of transport fluid required
Blood supply to different tissues can be varied depending on demand
Delivery of oxygen and nutrients more efficient
What do elastic fibres provide in blood vessels?
Flexibility
What is the role of smooth muscle in blood vessels?
To adjust lumen size
What is the role of collagen in blood vessels?
Structural support
What are the main differences between veins and arteries?
Veins have a larger lumen and arteries have more elastic tissue. Veins have valves typically.
What is the typical diameter of an artery?
5000 micrometres
What is the typical diameter of a capillary?
10 micrometres