Mitochondrial DNA (mtDNA) is a type of DNA that is carried by both men and women but is only inherited from their mother. Mothers, in turn, inherit their DNA from their mothers ... and so on back in time along one's maternal line.

All persons connected by pink lines have common mtDNA

Note above that there is no contribution from your paternal line, or from any other female ancestor other than ones in your direct maternal line (as shown below).