When a patient is on a kidney hemodialysis machine, dissolved substances move from the patient's blood to the fluid in the machine primarily by:

Question

Quizplus · Accepted Answer

The movement of dissolved substances from the patient's blood to the fluid in the machine occurs primarily by diffusion, as there is a concentration gradient that drives the movement of solutes across a semipermeable membrane. Osmosis refers to the movement of water across a semipermeable membrane, which may occur during hemodialysis but is not the primary mechanism for the removal of solutes. Active transport involves the movement of molecules against a concentration gradient, which is not typically involved in hemodialysis. Pressure on the blood exerted by the machine and filtration are also not the primary mechanisms for the removal of solutes during hemodialysis.

When a Patient Is on a Kidney Hemodialysis Machine, Dissolved