Blood flow is directly affected by pressure gradients; it flows from areas of high pressure to areas of low pressure.
Blood Flow and Pressure Gradients
Blood doesn't just randomly move around the body; it follows specific paths dictated by pressure. According to the SEER Training Modules, blood flow is analogous to other fluids in that it moves along a pressure gradient:
- High to Low: Blood always flows from a region of higher pressure to a region of lower pressure.
- Direction: The direction of blood flow is determined by the decreasing pressure gradient, which in the systemic circulation is from arteries to capillaries, and then to veins.
Think of it like water flowing downhill. Gravity (in this case, pressure) is the driving force.
Pressure and Resistance
While the reference provided doesn't go into detail about resistance, it's crucial to understand that pressure is only one component affecting blood flow. Resistance within the blood vessels also plays a significant role. Blood flow can be calculated using the following simplified relationship, akin to Ohm's Law in electricity:
Blood Flow = Pressure Gradient / ResistanceSummary
| Factor | Effect on Blood Flow |
|---|---|
| Pressure | Directly proportional |
| Resistance | Inversely proportional |
In essence, the greater the pressure difference between two points, the greater the blood flow. However, higher resistance within the blood vessels reduces the overall flow. The body finely tunes both pressure and resistance to ensure adequate blood delivery to all tissues.
