Transport Systems in Multicellular Animals Flashcards
How do most large multicellular animals transport substance around their body?
In their blood using their circulatory system
What does the circulatory system consist of?
Heart, blood and blood vessels
How many type of circulatory systems are there?
4
What are the 4 types of circulatory systems?
-Single
-Double
-Closed
-Open
What is a single circulatory system?
Where blood passes through the (usually 2 chambered) heart once per complete circuit of the body
What animal is an example which uses a single circulatory system?
Fish
What is a double circulatory system?
Where blood passes through the heart twice per complete circuit of the body
What is the double circulatory system compromised of?
-Pulmonary Circuit (lungs & back)
-Systematic Circuit (body & back)
Who have a double circulatory system?
Most mammals, birds, amphibians and reptiles
What is the first reason why a double circulatory system is more efficient?
No mixing of oxygenated and deoxygenated blood so more O2 reaches the body cells as the concentration gradient is steeper.
What is the second reason why a double circulatory system is more efficient?
Blood receives another (more forceful) ‘pump’ after it’s been to the lungs so blood in systematic circuit is under higher pressure so reaches body cells more quickly.
What is a closed circulatory system?
Where blood is enclosed blood vessels.
Who has a closed circulatory system?
All vertebrates and some molluscs
What is an open circulatory system?
Blood (haemolymph) flows freely and slowly through body cavity directly bathing in tissues
What does haemolymph do?
Carries nutrients, hormones and some O2 which has been brought in and CO2 which will be removed by tracheal system.
Where is an open circulatory system found?
In larger invertebrates (insects)
What is the first step in an open circulatory system in insects?
Haemolymph is pumped from back to front along a single artery.
What is the second step in an open circulatory system in insects?
Haemolymph leaves artery and enters the body cavity directly bathing the insects organs
What is the third step in an open circulatory system in insects?
Haemolymph returns to heart through valves called ostia.
What is the first disadvantage of single circulatory systems such as in fish?
Blood pressure drops as blood passes through gill capillaries
What is the second disadvantage of single circulatory systems such as in fish?
Blood flow slowly through as its under low pressure
What is the third disadvantage of single circulatory systems such as in fish?
Rate of delivery of oxygen/nutrients to respiring tissues is limited
What is the first advantage of a closed circulation system over and open system?
Blood travels at higher pressure and therefore flow is faster
What is the second advantage of a closed circulation system over and open system?
Oxygen/nutrients supplied and CO2/Urea removed quicker
