Human Anatomy is the study of the structure of the human body and how the body parts are organized. Human Physiology is the study of the functions of body parts.
Anatomy is the study of structure and physiology is the study of functions. But actually these two fields of study is so interrelated and closely associated with each other that it is difficult to separate them.
For example let’s think about the heart. Anatomy studies the size,shape and coverings of it. Its position related to other organs and chest wall. What are the blood vessels that go into and comes out if it? How the wall of the heart is made? How many layers are there? How many chambers are there? How many blood vessels and nerves supply the heart? How many valves does the heart have? etc.
The physiology of the heart studies that what does it do? How does it contract? What regulates the heart? How does the heart is regulated? What happens in a cycle of its contraction and relaxation? What the valves do? How do they do that? etc.
In a word anatomy deals with how our body is made and physiology deals with what does it do and how does it do it?
Anatomy and physiology are related, because structure helps to function and functions shape the structure.