This book is primarily aimed at students of biological sciences, who, before engaging deeply in the field of Physiology of mammals (specifically humans and pets), should first become acquainted with the basic principles of their physiological functions, which, notably, are common.

This book serves as a starting point for further in-depth study of Physiology (detailed mechanisms, theories, as well as some qualitative and quantitative differences regarding the functioning of various mammals).

In conclusion, this work provides a concise presentation, a general overview, and a review of core topics in Physiology, without details, references to specific mechanisms, etc. It offers a general picture of the physiological functioning of the most essential systems of the organism, such as the nervous system, muscular system, circulatory system, urinary system, respiratory system, digestive system, and endocrine system.