Biology · Structural Organisation in Animals · NEET
Both words are correct together. Blood is a fluid (liquid) connective tissue. "Fluid" describes the state of its matrix (plasma is liquid). "Connective tissue" describes its tissue class. NCERT calls it a special/specialised connective tissue with a fluid matrix. So if the exam asks the tissue type, answer connective tissue; if it asks the sub-type, answer fluid/specialised connective tissue.
This is the most common confusion. Connective tissues are NOT named because they physically glue organs together. They are grouped by structure: living cells scattered in a large non-living extracellular matrix that all cells share. Blood matches this exactly (cells in plasma). Function is a bonus, not the rule. In fact blood does "connect" the body functionally by transporting oxygen, food, hormones and wastes between organs.
The matrix of blood is plasma, a pale-yellow fluid that is about 90 to 92 percent water. The rest is plasma proteins (albumin, globulins, fibrinogen), glucose, ions, hormones and dissolved gases. Because this matrix is liquid instead of solid or jelly-like, blood is called a fluid connective tissue. Remember: bone matrix is hard, cartilage matrix is pliable, blood matrix is fluid.
Blood has no permanent fibres floating in it, unlike areolar tissue or tendons that have collagen and elastin fibres. But it CAN form fibres when needed: during clotting, the soluble protein fibrinogen changes into insoluble fibrin threads. So blood carries the fibre-making material dissolved in plasma rather than as ready-made fibres.
Blood, like almost all connective tissues, develops from the mesoderm (the middle germ layer). This shared origin is one reason it is classed with bone, cartilage and areolar tissue rather than with epithelium (mostly ectoderm/endoderm) or neural tissue (ectoderm). NEET sometimes tests tissue origin, so link connective tissue with mesoderm.
The formed elements are RBCs (erythrocytes), WBCs (leucocytes) and platelets (thrombocytes). They are the cellular part embedded in the plasma matrix. Note that mature mammalian RBCs have no nucleus and platelets are cell fragments, but for tissue classification they still count as the formed elements suspended in matrix, satisfying the connective-tissue definition.
Which of the following is not a connective tissue?
Match List I and List II. A. Mast cells, B. Inner surface of bronchiole, C. Blood, D. Tubular parts of nephron; I. Ciliated epithelium, II. Areolar connective tissue, III. Cuboidal epithelium, IV. Specialised connective tissue.
Try the real previous-year questions from this chapter — each with the answer and a full solution.
Because it has living cells (RBCs, WBCs, platelets) embedded in a large fluid extracellular matrix called plasma, which is the defining feature of every connective tissue.
Blood is a fluid (liquid) connective tissue, grouped under specialised connective tissue along with cartilage and bone in NCERT.
Yes. Lymph is also a fluid connective tissue. It is similar to plasma but has fewer proteins, no RBCs and no platelets, and it contains lymphocytes.
Blood develops from the mesoderm, the same middle germ layer that forms other connective tissues like bone, cartilage and areolar tissue.
Blood has no free-floating fibres normally, but during clotting the dissolved protein fibrinogen turns into fibrin fibres, so the fibre-forming material is present in the plasma.
