What we know:

     In order to understand the 'why', we must first understand what blood is and how it operates. Circulating blood comes from the circulatory system in our bodies. The circulatory, or cardiovascular system, supplies oxygen and nutrients to our bodies while removing waste through blood. The heart is the major organ in the system, and pumps blood that flows through the arteries, veins, and capillaries. This back-and-forth transport is what carries oxygen-rich blood across tissues and oxygen-poor blood back to the lungs. There are two main circulatory routes: pulmonary and systemic. Pulmonary circulation focuses on creating a closed circuit between the heart and the lungs. Systemic circulation moves oxygenated blood into tissues and deoxygenated blood away from tissues.      

Blood is more than a liquid

    What's most fascinating about blood is that even though most tissues are packed tightly together in solid forms, blood is considered a liquid tissue. It is a type of tissue known as connective tissue, in which its job is to maintain the structure of organs and provide internal support throughout the body. Within connective tissues are specific categories: loose, dense, and specialized connective tissues. Blood falls under this specialized connective tissue due to its role in the transportation of nutrients and oxygen throughout the body. Because blood is a liquid, it can also travel easily throughout the body, reaching even the tiniest parts like your fingertips and toes. 

To wrap up

    Blood is known as a circulating tissue because they are tied to all the cells within our bodies. Additionally, its liquid structure gives it a very loose form, which is indicative of the basic structure within connective tissues. It is because of the supportive nature of blood that make it impossible to live without. Every second, millions of blood cells die and are born, creating a nonstop cycle intended to keep us alive and healthy. For these reasons, blood earns its title as a unique kind of tissue. 

Thank you for reading.