Lower Body vs. Upper body Exercises

I recommend total body workouts, rather than splitting up your workouts into upper or lower days. Unless of course you are a body builder or competitor or along those lines. Your training would be completely different.
But for the rest of us who are trying to lose weight, firm up or build a little muscle, total body workouts are the way to go.
However, did you know that many lower body exercises also work the upper body?
For instance, deadlifts work your upper and lower back as well as your shoulders to a large degree - not just the hamstrings and glutes.
Back Squats work your abs and back, not just the legs.
Front squats also work your abs and shoulders, and goblet squats work your biceps, shoulders and upper back.
Walking lunges (or any kind of lunges) are also great for the traps and shoulders if you are lifting heavy enough. Lunges with a 25 lb weight in each hand works your lower body as well as the upper body much differently than holding 2 8 lbers!

Focusing on the compound movements above as well as hip bridging/thrusting, and push ups and pull ups is a great way to get into tip top shape.

There really isn't a need for bicep curls, side raises, tricep kick backs and the like. Of course if it is part of your routine and you like it, and it works for you, do it! But I would not do those exercises in place of the compound lower body movements, and pull ups and push ups. These exercises will vastly change your body to a greater degree.

Happy lifting!