pressure filtration

• pressure filtration causes plasma to pass through capillary walls into the tissue fluid surrounding the cells
• tissue fluid supplies cells with glucose, oxygen, and other substances
• carbon dioxide and metabolic waste diffuse out of the cells and into the tissue fluid to be excreted. much of the tissue fluid returns to the blood
• lymphatic vessels absorb excess tissue fluid and return it as lymph to the circularatory system
• Tissue fluid and blood plasma are similar in composition, with the exception of plasma proteins, which are too large to be filtered through capillary walls. Blood plasma contains plasma proteins and tissue fluid does not.