MICROANATOMY

Detailed explanation-1: -The walls of the capillaries are permeable to oxygen and carbon dioxide.

Detailed explanation-2: -The glomerular capillary is relatively impermeable to most serum proteins. This impermeability that leads to virtual exclusion of proteins like albumen from the glomerular filtrate but permits complete permeation by inulin is thought to be related in part to the molecular dimensions of the protein.

Detailed explanation-3: -Specialized capillaries in endocrine organs have pores, fenestrae, in the plasma membrane. Fenestrae allow rapid exchange of solute and molecules such as hormones. Transcellular gaps provide a route for inflammatory cells, which, however, also may exit through paracellular junctions.