Final answer:
Osmotic pressure is the force that causes NaCl, K, water, bicarbonate, glucose, and amino acids to be reabsorbed into the bloodstream. It is determined by the difference in solute concentration between the blood and tissue fluid.
Step-by-step explanation:
The force that causes NaCl, K, water, bicarbonate, glucose, and amino acids to be reabsorbed into the bloodstream is the osmotic pressure. Osmotic pressure is determined by the difference in solute concentration between the blood and tissue fluid. When the blood has a higher colloidal concentration and lower water concentration than the tissue fluid, it creates a higher blood colloidal osmotic pressure (BCOP) which draws water and dissolved molecules back into the capillary.