Characteristics of the Human Body as a Biological System

Biological systems include complex systems of different levels of organization: cells, tissues, organs, organ systems, and organisms. There are also
biological systems at the supra-organism level – populations, species, biocenoses, ecosystems, and the biosphere as a whole.

The human body is a holistic biological system consisting of interconnected and interdependent components – cells, tissues, organs, and organ systems.
No component of the human body can exist independently for long because it cannot perform all the functions of life simultaneously. The interconnections
between components and the emergence of differences during their interaction lead to mutual dependence, which prevents the components of the system
from existing outside of it.

Regulation of Physiological Processes

Physiological processes in the human body occur in a coordinated manner due to the existence of specific regulatory mechanisms. The main regulatory
systems of the body are the nervous and endocrine systems, which use mechanisms of neural and humoral regulation.

• Humoral Regulation: (from Latin "humor" - fluid) is carried out with the help of chemical substances that enter the blood from various organs and
  tissues of the body and are distributed throughout the organism.

• Neural Regulation: Physiological processes are regulated by the influence of the nervous system on cells, tissues, and organs. Neural influences
  are always directed at specific organs and tissues and spread hundreds and thousands of times faster than chemical substances.

Neural and humoral methods of regulation are closely interconnected. The activity of the nervous system is constantly influenced by chemical substances
carried by the bloodstream, while the formation and release of most chemical substances into the blood are under the constant control of the nervous system.

Regulation of physiological functions in the body cannot be carried out using only neural or only humoral regulation; it is a unified complex of neurohumoral
regulation of functions.

Additional Aspects

1. Cellular Level: Cells are the basic structural and functional units of the body. They combine to form tissues that perform specific functions.

2. Tissue Level: Tissues consist of cells of the same type and perform certain functions. Examples of tissues include epithelial, muscle, nervous,
   and connective tissues.

3. Organ Level: Organs are composed of different types of tissues and perform specific functions. Examples of organs include the heart, liver, lungs,
   and kidneys.

4. System Level: Organ systems consist of several organs that work together to perform specific functions. Examples of organ systems include
   the respiratory, digestive, nervous, and endocrine systems.

Interaction of Systems

The human body functions as a single entity due to complex interactions between different organ systems. These interactions ensure the maintenance of
 homeostasis, adaptation to environmental changes, and the performance of vital functions.