they are a heterogeneous group of tissues that contain fibroblasts ( type example -- the subcutaneous mucochondroid of the cobitidae ) or hyaline cells ( type example -- the mucochondroid around the medulla oblongata and spinal cord of rasbora heteromorpha ) , embedded in a pale-staining matrix in which there are variable numbers of collagen fibres and blood vessels .
C0016030
fibroblasts
C0007634
cells