What type of transport allows nutrients to leave capillaries and enter tissue fluid?

The movement of nutrients from capillaries into tissue fluid occurs primarily through simple diffusion. This process allows molecules to move from an area of higher concentration (inside the capillaries) to an area of lower concentration (in the tissue fluid) without the need for additional energy or assistance from transport mechanisms like protein channels. The concept of concentration gradients plays a crucial role in this process, as nutrients will naturally flow towards areas where they are less concentrated, helping to ensure that the tissues receive the necessary substances for their metabolic needs.

In contrast, facilitated diffusion requires specific transport proteins to help molecules that cannot easily pass through cell membranes. Active transport involves the use of energy to move substances against their concentration gradient and is not typically how nutrients pass from capillaries to tissue fluid. Bulk flow generally refers to the movement of fluids and solutes due to pressure differences and is not the primary mechanism for nutrient transfer at the capillary level. Thus, simple diffusion is the most direct and efficient process for nutrients exiting the bloodstream into surrounding tissues.