Among the given structures of cells, axon is not present in connective tissues. The axon is the part of a neuron that sends the signal. Axons are long, thin and tendril-like and carry an electrical signal from the cell body (soma) to the synapse. The cells of a connective tissue include fibroblasts, adipocytes, macrophages, mast cells and leucocytes. Three types of fibresare found in a connective tissue: collagen, elastic fibres, and reticular fibres.