Levels of Structural

The Ultimate Guide to Levels of Structural Organization

Before you read levels of structural organization, you should know the underlying structure architecture of the human body. In simple words, how the smallest parts of the body assembled into larger structures. The organization of the body discussed here in terms of six distinct levels of complexity. It starts from the smallest chemical building blocks to the unique human organisms. 

Scientists usually prefer to consider the smallest building blocks of matter, like atoms and molecules, to study the chemical level of the organization. All the matter in the universe is composed of one or more unique pure substances called elements. The smallest unit of these elements is an atom. 

Levels of Structural Organization

The following are the primary levels of structural organizations in the human body. 

Chemical Level 

It includes atoms, which combine to form molecules and molecules combine to form organelles. It is the simplest level in the structural organization. Chemicals are often known as nucleotide bases, which are the foundations of genetic code. 

Cellular Level

Cells compose the cellular level. Each cell performs unique tasks in the human body. However, individual cells also have some standard functions that vary in size and shape. Humans developed from a single fertilized egg cell into complex organisms containing trillions of cells. 

Tissue Level

Tissues are a group of cells that have standard functions. There are four main types of tissues in humans, including epithelium, connective, muscle, and nervous tissue. Each tissue performs a different role in the human body. 

Organ Level

The organ level is composed of two different types of tissues that perform specific functions in our body. For example, it includes the brain, liver, and stomach. At the organ level, complex tasks begin to emerge. 

Organ System Level

Organ systems work together to accomplish a common purpose. There are various organ systems in the human body. For example, the heart and blood vessels work together and circulate blood throughout the body, included with oxygen and nutrients. 

Organismal Level

It is the highest level of structural organization. In other words, it is the sum of all fundamental levels working together. Organisms can be unicellular or multicellular. In simple terms, human beings as a whole are organisms. Additionally, scientifically they are divided into five kingdoms.