Porosity is the ratio of pore volume to its total volume. Sebaceous glands inside the pore of the skin produce sebum. They can differ enormously depending on the combination of electrode porosity, pore size and electrolyte. Ion channels are pore-forming membrane proteins that allow ions to pass through the channel pore. The capillary head depends on soil pore size. Alpha subunits form the actual conductance pore. Dialyzer membranes come with different pore sizes. Ionotropic receptors form an ion channel pore. The ions pass through the selectivity filter of the K channel pore. There is a clear proportionality between pore throat radii and hydraulic conductivity. Increased concentrations of acrylamide result in decreased pore size after polymerization. Water molecules traverse through the pore of the channel in single file. It is a transmembrane tube that forms most of the TOC pore itself. Groundwater is fresh water located in the subsurface pore space of soil and rocks. The eccrine gland opens out through the sweat pore.