Test Your Knowledge of the Circulatory System

10 Questions

The movement of molecules from high to low concentration

Bulk flow

The muscular heart

Small animals

Open and closed circulatory systems

Arthropods and most mollusks

The presence or absence of vessels

The heart

The composition of blood and the cardiac cycle

Understanding the limitations of diffusion and the necessity of bulk flow

Study Notes

Diffusion is the net movement of molecules from high to low concentration, which is slow and limited for delivering nutrients and eliminating waste from body cells.
Bulk flow is the movement of a fluid from high to low pressure, which is essential for rapid transport of nutrients and oxygen to body cells.
The motive force for bulk flow in animal circulatory systems is the muscular heart, which pumps blood to body cells via a network of interconnected vessels.
Small animals do not need circulatory systems as they rely on direct contact with the external environment to provide the motive force for bulk flow.
Big animals require circulatory systems, with two types: open and closed circulatory systems.
Arthropods and most mollusks have open circulatory systems, while cephalopods, annelids, and vertebrates have closed circulatory systems.
Closed circulatory systems use blood confined within vessels, while open circulatory systems use hemolymph that flows through open-ended vessels and sinuses.
The pressure gradient is generated by the heart in both types of circulatory systems.
The composition of blood and the cardiac cycle are important components of the mammalian cardiovascular system.
Understanding the limitations of diffusion and the necessity of bulk flow, and the physical laws that govern blood pressure and flow velocity in circulatory systems are crucial learning outcomes for subsequent lessons.