Transport in animals- Blood and tissue fluid Flashcards
State 5 reasons why most animals need specialised transport systems.
- The demands of most multicellular animals are high- so diffusion over long distances is not enough to supply the quantities needed
- The SA:Vol ratio gets smaller as the multicellular organisms get bigger
- Molecules such as hormones or enzymes may be made in one place but needed in another
- Food will be digested in one orgna system but needs to be transported in every cell to be used for respiration
- Waste products of metabolism need to be removed from the cells and transported to excretory systems
Describe how diffusion distance, SA, Volume and SA:Vol ratio vary with increasing organism size.
Diffusion distance increases as the organism gets bigger
SA gets relatively smaller as the size increases
SA:Vol ratio gets smaller as the size increases.
Describe how the level of activity of an organism is related to demand for oxygen and glucose.
As the level of activity increases the more need for oxygen and glucose- respiration
Explain how volume is related to demand and surface area is related to supply. Also explain why supply meeting demand requires adaptations as organisms increase in size.
- A larger volume means a larger volume of cells which means a higher metabolic demand.
- Surface area gives a surface for the exchange of nutrients and gases- larger SA means a faster supply
- When SA:Vol ratio is so small that the organism cannot meet its metabolic demands adaptations are required to develop a more efficient transport system.
Define mass of fluid
When substances are transported in a mass of fluid with a mechanism for moving the fluid around the body
Define circulatory system
The transport system of an animal
Define closed circulatory system
A circulatory system where the blood is enclosed in blood vessels and does not come into direct contact with the cells of the body beyond the blood vessels.
Define open circulatory system
A circulatory system with a heart but few blood vessels to contain the transport medium. The blood vessels open up to a pool of blood called the haemoceol
Define haemolymph
The transport medium of blood in insects
Define single circulatory system
A circulatory system where the blood flows through the heart and is pumped out to travel all around the body before returning to the heart.
Define double circulatory system
A circulatory system where the blood travels twice through the heart for each complete circulation of the body. The first circulation blood is pumped by the heart to the lungs. In the second circulation oxygenated blood is pumped by the heart to the brain and body to supply cells with Oxygen
Define pulmonary circulation
The flow of blood away from the heart through the lungs where oxygenation occurs and then returns to the heart again
Define systemic circulation
Flow of blood away from the heart to the brain,liver, kidney, stomach and other organs, the limbs, and the muscles of the body, and then the return of this blood to the heart.
State some examples of organisms with each type of circulatory system.
Fish- Closed and single circulatory system
Insect- Open circulatory system, (single probs)
Human- Closed and double circulatory system
Describe the general features of circulatory systems.
- They have a liquid transport medium that circulates around the system
- They have vessels that carry the transport medium
- They have a pumping mechanism to move the fluid around the system.
Draw a table to show the similarities and differences between, and advantages and disadvantages of, open and closed circulatory systems.
Open: 1. Supply and disposal of materials is very slow 2. Blood flow can't be regulated 3. Blood flows at a slow velocity Closed: 1. Supply and disposal of materials is faster 2. Blood flow can be regulated 3. Blood flows at a fast velocity
Draw a table to show the similarities and differences between, and advantages and disadvantages of, single and double circulatory systems.
Double:
1. Double circulatory systems are important because they ensure that we are giving our tissues and muscles blood full of oxygen, instead of a mixture of oxygenated and deoxygenated blood.
2. Requires more energy
3. The blood pressure can be high in the systemic circuit, while remaining low and safe in the pulmonary circuit
Single:
1. Can only maintain one pressure- always low so doesn’t damage capillaries.
2. Fish aren’t as active so their system is sufficient for their needs
Explain the differences between the pulmonary and systemic circulations.
- Pulmonary circulation refers to the circulation of blood in which deoxygenated blood is pumped from the heart to the lungs and oxygenated blood is returned to back to the heart. Pulmonary circulation only occurs between the heart and the lungs.
- Systemic circulation refers to the circulation of blood in which oxygenated blood is pumped from the heart to the body and deoxygenated blood is returned back to the heart. Systemic circulation occurs between the heart and the entire body