Slide 8/28
How does fluid escape out of blood vessels?

• The smallest blood vessels are known as capillaries.
• Blood contain substances that "hang on" to fluid. This ability is known as "oncotic pressure"
• The pressure within the heart during filling is reflected back to the capillaries (capillary pressure)
• Blood will stay within capillaries as long as the capillary pressure is lower than the oncotic pressure