A fluid medium containing proteins and salts
Explanation
Blood is a specialized fluid connective tissue. Like all connective tissues, it consists of cells suspended in a matrix. However, the nature of the matrix in blood is distinct because it is fluid and does not contain fibres under normal circulating conditions.
Option Analysis
- A jelly-like substance containing fibres is incorrect: A jelly-like substance containing fibres typically describes the matrix of connective tissues such as areolar tissue or cartilage (which is semi-solid), not blood.
- A fluid medium containing proteins and salts is correct: The matrix of blood is called plasma. It is a fluid medium that constitutes about 55% of the blood volume. Plasma contains proteins (such as albumin, globulin, and fibrinogen), salts (electrolytes), hormones, and dissolved gases. It transports nutrients and waste products throughout the body.
- A rigid compound of calcium and phosphorus is incorrect: A rigid compound of calcium and phosphorus describes the matrix of bone tissue, which provides structural support to the body.
- A dense fibrous network is incorrect: A dense fibrous network characterizes dense connective tissues, such as tendons and ligaments, which require high tensile strength.
Key Takeaway: The matrix of human blood is plasma, a fluid medium containing proteins and salts, distinguishing it from other connective tissues that have solid or semi-solid matrices with fibres.