Hello! There are different areas along the intestines that are specified to absorb certain nutrients (division of labour) and there are also different enzymes for proteins, fats, carbohydrates etc. It’s a bit like lock and key, so they are not digested and absorbed all at once 🙂
Firstly these are broken down in our stomach in small intestine by enzymes which allows them to be absorbed. Protein which is split into amino acids and sugars go to the liver with many of the vitamins where they are processed and some are stored. The fat as it doesn’t dissolve is carried in the lymphatic circulation and appears in the blood near our hearts before finding its way to the liver where it is processed and sorted more or is stored in our fat cells
The body is very smart in prioritising energy for processes that it knows are important for survival. So energy is first used to support basic activity of vital organs and maintain the bodies general operating systems. If we put the body under stress, like exercise, then the body has to decide what tissues/organs need energy quickly and will prioritise this delivery system. So bloodflow increases to functional organs/tissues and slows to inactive tissues/organs.