8 Transport in Animals Flashcards
1
Q
Define”mass transport”
A
The bulk movement of substances in one direction
2
Q
Why is mass transport needed in multicellular organisms?
A
- small SA:V
- large metabolic demand
- waste products not removed efficiently without mass transport
3
Q
Describe “closed circulatory system”
A
- blood always remains inside blood vessels
- blood is pumped using the heart
- only certain substances leave and enter via diffusion
- the two types are single and double
4
Q
Describe “single closed circulatory system”
A
- blood passes through the heart once per circuit
- heart receives deoxygenated blood from body then pumped to gill
5
Q
Describe “double closed circulatory system”
A
- blood passes through the heart twice per circuit
- as a result the mammalian heart has 2 sides
- pulmonary circuit starts from deoxygenated blood to lungs then back to heart
- systemic circuit starts from oxygenated blood to body then back to heart
6
Q
Benefits of double circulatory system?
A
- maintains high blood pressure
- higher flow speed compared to single
- maintains higher concentration gradient
7
Q
Describe “open circulatory system”
A
- only a few vessels involved
- blood is pumped directly in to the body cavity (haemocel)
- blood is under low pressure
- blood comes in to direct contact with body cells
8
Q
Describe the circulatory system in insects
A
- gas exchange in insects take place at the tracheal system
- blood (haemolymph) is insects is used to transport nutrients and nitrogenous waste
