[4] In 1869, he became the assistant to the Professor of Physiology at the University of Edinburgh, John Hughes Bennett, pursuing his own research into the nervous system and special senses.

McKendrick went on to be elected as a Fellow of the Royal Society of Edinburgh in 1873, having been proposed by Sir William Turner, serving as a councillor and eventually the Vice-President from 1894 until 1900.

[5] He took up a post at the University of Glasgow in 1873, first as an extramural lecturer (one of his students was the physician Sophia Jex-Blake) and then as Regius Professor of Physiology in 1876.

[6] John McKenrick was a popular lecturer, raising significant funds for modernising his department and leading it into concentrating on the study and teaching of physiology.

[12] In 1891 and 1895 was invited to deliver the Royal Institution Christmas Lecture on Life in Motion; or the Animal Machine and Sound, Hearing and Speech respectively.