So the prerequisites for the MD are second year Physiology, Anatomy and Biochemistry.
The prerequisites for Physiology and Anatomy are the two first year Biology subjects, and the prerequisites for Biochemistry are the two first year Chemistry subjects. So you will need to complete these first year subjects in order to be able to take the prereqs.
Civil systems in first year, I'm pretty sure, requires you to do first year Maths (Calculus 2 and Linear Algebra) and ESD1 & ESD2. If you have done specialist maths you will not be required to undertake Calculus 1 before completing Calculus 2 or Linear Algebra.
So a rough sample plan could be
1ST YEAR 1ST SEMESTER: ESD1, Calculus 2, Chemistry 1, Biology of Cells and Organisms
1ST YEAR 2ND SEMESTER: ESD2, Linear Algebra, Chemistry 2, Genetics & The Evolution of Life
Then you have four semesters to fit the three prereqs in whenever you want. Also, alternatively you could do Chemistry 2 in summer if you didn't want such a full on semester (Chemistry 2 and ESD2 are fairly tough subjects). You could also chop and change and do some of the subjects in second year and then complete one of the prereqs in third year or something like that. There is quite a bit of flexibility. Remember though that you will be required to undertake at least 4 breadth subjects (and up to 6) in your degree. The sample plan I gave did not include any breadths, as I would be assuming you would take these in second and third year. Also remember you are allowed to undertake a maximum of 9 level 1 (i.e. first year) subjects throughout your degree