Yes, the capillaries in the brain are indeed the least permeable compared to those in the rest of the body. This is primarily due to the presence of tight junctions between endothelial cells, which form the blood-brain barrier. This barrier restricts the passage of substances, thereby protecting the brain from potentially harmful compounds while allowing essential nutrients to pass through.
rock type
clay
Capillaries.
Becuase the resistance is spread across thousands of capillaries.
Claystone is typically the least permeable fairview rock due to its dense and compact nature. It has very low porosity and minimal interconnected pore spaces, which hinder the flow of fluids through the rock.
Clay soil is the least permeable because it has smaller particles that are closely packed together, reducing the spaces for water to flow through. Silt and loam soils have larger particles and more pore spaces, making them more permeable than clay soil.
Clay is considered the least permeable type of soil, meaning water drains slowly through it due to its small particle size and high compaction. This can lead to waterlogging and poor drainage in clay soils.
In comparison with their cousin the horse, not in the least.
Last, but not least.
Giraffs
craniopharyrgioma
Brain cells...