Hi, make it a piece of cake for yourself by asking the six wise men: How, Why, Where, When, Which & What [particyularly the first two].
In nature there is a reason for everything having evolved the way it has and does - if you prefer to believe in god, so be it - just convince yourself that if he/she had existed, he/she would have been supremely logical and intelligent.
Try and learn your anatomy and physiology by interlinking various parts of the body and working out why things are as they are.
JUST A FEW ILLUSTRATIVE e.g.-s:
HEART: Why are the individual myocytes therein connected to form syncytia? ANS: the whole of the ventricles have to beat nearly simultaneously to allow them to pump out blood in a co-ordinated way - therefore, the cardiomyocytes must contract simultaneously, and passage of the electrolytes that bring about depolarization [mainly Na+] between myocytes allows this to happen. When things go wrong, as in ventricular fibrillation [one cause of cardiac arrest, the other being asystole], the myocytes contract independently in an uncoordinated way and there is no cardiac output.
a] Why are there millions of minute alveoli for gas exchange? ANS. Having numerous, tiny alveoili increases the surface area of the lungs tremendously so speeds up diffusion of oxygen into the blood.
b] Why is the diameter of the capillary around the alveoli about the same as the diameter of a red blood cell [7 microns]? ANS: Erythrocytes barely move through the capillary i.e. slowly, so there is time for diffusion of oxygen.
Why are there additional oblique smooth muscle cells on top of the longitudinal and circular muscle cells of other parts of the GI tract? ANS: one of the functions of the stomach is to churn "food" into smaller pieces and to mix it with the digestive enzymes - this can only be done by muscle fibres in all meridians not just 2-D.
Why are the endopeptidases secreted earlier [higher up] the GI tract, and the exopeptidases only in the distal [lower] part? ANS: if you break up a protein molecule into shorter chains first [using endopeptidases which break peptide bonds near the midpoints of the polypeptide] first, then you have more "ends" [on many shorter peptides] for the exopeptidases to act on thus enhancing efficiency! Is that not ingenious? DO NOT underestimate the genius of nature!
Why do hepatocytes, plasma cells and striated muscle cells have rich RER? Ok what does RER do? ANS: Yes oc cos all these cells need to synthesize proteins, yeah? [hepatocytes: albumin + blood clotting factors II, VII, IX and X][plasma cells: antibodies = immunoglobulins [gammaglobulins][myocytes: myosin + actin].
The list goes on and on ---- look at anatomy and physiology in this light and you will sail through it with ease!
Best of luck!