Blood is a type of
- (a)Epithelial tissue
- (b)Muscular tissue
- (c)Nervous tissue
- (d)Connective tissue
Correct — D, connective tissue. Blood is classed as a connective tissue because it develops from mesoderm and is made of cells — red blood cells, white blood cells and platelets — suspended in an extensive fluid matrix called plasma. Cells scattered in an abundant extracellular matrix is the defining feature of connective tissue, and blood fits it as a fluid connective tissue that links and services the body's organs.
- (a)Epithelial tissue — Epithelial tissue is made of tightly packed cells with almost no intercellular matrix and covers or lines body surfaces; blood, with its abundant fluid matrix, is not epithelial.
- (b)Muscular tissue — Muscular tissue is built from contractile fibres that produce movement; blood cells do not contract.
- (c)Nervous tissue — Nervous tissue is made of neurons and glia that conduct electrical impulses; blood neither conducts impulses nor is built from neurons.
Animal tissues fall into four groups — epithelial, connective, muscular and nervous. Connective tissue is marked by relatively few cells embedded in a large amount of extracellular matrix. Blood has this pattern: its cells float in a liquid matrix (plasma), so it is a fluid connective tissue.
The liquid nature of blood is exactly what makes students hesitate, yet a fluid matrix is a hallmark of connective tissue. Comparing the four tissue types shows why blood cannot be epithelial (little matrix), muscular (contractile) or nervous (neurons).
- Blood is a fluid connective tissue with cells suspended in a liquid matrix (plasma).
- Its formed elements are red blood cells (erythrocytes), white blood cells (leucocytes) and platelets (thrombocytes).
- Connective tissue is defined by cells scattered in an abundant extracellular matrix.
- Bone and cartilage are solid connective tissues; lymph, like blood, is a fluid connective tissue.
- Being misled by blood being a liquid — a fluid matrix is exactly what marks it as a connective tissue.
- Confusing connective tissue (much matrix) with epithelial tissue (little matrix).
Asked by classifying blood among the four animal tissue types, or by asking which tissue has a fluid matrix.
No directly related past PYQ was found.
- practice — not a real PYQ
Which one of the following is a fluid connective tissue?
- (a)Cartilage
- (b)Blood
- (c)Bone
- (d)Tendon
Answer(b) Blood — cells suspended in a liquid matrix (plasma) make it a fluid connective tissue.
- practice — not a real PYQ
The liquid matrix in which blood cells are suspended is called
- (a)Serum
- (b)Plasma
- (c)Lymph
- (d)Haemoglobin
Answer(b) Plasma — the fluid extracellular matrix of blood.