Question

Why do we consider blood as a connective tissue?

Answer 1

Connective tissues are one of the four basic types of animal tissues and are the specific tissues that arise from the embryonic mesoderm and have cells scattered throughout the body. They connect different body systems and hence are called connective tissues.

Complete Step by Step Answer:
Blood is considered as a type of connective tissue because of two main reasons:
- Like the other connective tissues, blood too, originates from the embryonic mesoderm.
- Blood connects the different body systems, plays a role in the gaseous exchange of the body, carries nutrients to all the parts of the body, and also drains the waste products. Blood has an extracellular matrix called plasma that has the red blood cells, white blood cells, and platelets floating in it. Connective tissue is one of the four basic types of animal tissue, that include epithelial tissue, muscle tissue, and nervous tissue. Generally, all connective tissues include three components: fibres, ground substance, and cells. Connective tissues are classified as connective tissue proper and special connective tissues.
Special connective tissues include adipose tissue, reticular connective tissue, cartilage, bone, and blood.
Lymph or tissue fluid which is also considered a connective tissue is formed from the blood itself and hence does not arise from mesoderm cells directly. They are formed when plasma fluids are siphoned off from the capillaries. So, essentially lymph comprises all the components of blood except the proteins which do not exit the capillaries.

Note: Some schools of thought do not consider both blood and lymph as connective tissues as they lack fibers which is a component of connective tissues, but others overrule this thought based on other similarities.