1. Which of the following are components of all cardiovascular systems? Select the THREE answers that are correct.
a series of tubes
an organ for gas exchange
a circulating fluid
a cavity for nutrient and gas exchange
a pump
2. Why do larger animals have closed circulatory systems?
Closed circulatory systems feature a smaller network of blood vessels than open circulatory systems, which allows for more targeted delivery of oxygen and nutrients to cells
Closed circulatory systems do not have chambers in the heart, which lessens complexity in the system and increases efficiency in oxygen and nutrient delivery.
Closed circulatory systems are less complex than open circulatory systems such that oxygen and nutrients are delivered to cells more quickly.
Closed circulatory systems allow for mixing of blood with other bodily fluids, which increases the rate at which oxygen and nutrients are carried to cells.
• Closed circulatory systems deliver oxygen and nutrients to cells and carbon dioxide and waste from cells more efficiently than open circulatory systems.
