Fluids
Fluids (gases and liquids) are a common component of many physiological systems and having an understanding about some of their characteristics helps immensely with the understanding of some of these systems (the cardiovascular and respiratory systems in particular).
There are several definitions of what a fluid is, depending on the level of complexity you desire.
You can consider a fluid as:
You can consider a fluid as:
A substance that has no fixed shape, can flow, and offers little resistance to an external stress.
Both liquids and gases are fluids, and as such share many similar properties.
Flow
The ability to flow (fluidity) is the most important characteristic of fluids, hence their name.
Flow is the movement of a fluid, often through a tube or similar system.
Flow is the movement of a fluid, often through a tube or similar system.
We define flow as the volume of fluid passing a certain point in a specific period of time.
