glomerulus

:  a small convoluted or intertwined mass (as of organisms, nerve fibers, or capillaries): asa:  a tuft of capillaries that is covered by epithelium, is situated at the point of origin of each vertebrate nephron, and normally passes a protein-free filtrate from the blood to the surrounding Bowman's capsule—see renal corpuscleb:  the convoluted secretory part of a sweat glandc:  a dense entanglement of nerve fibers situated in the olfactory bulb and containing the primary synapses of the olfactory pathway—called also olfactory glomerulus