Question

Collagen fibres are secreted by
A) Mast cells
B) Macrophage
C) Histiocytes
D) Fibroblasts

Answer 1

Hint: Collagen fibres are a type of connective fibre in our body. They are in the form of long bundles and are made up of the protein−collagen. They are rigid and are not soluble. Collagen fibres provide elasticity and act as a connecting platform for all the cells. These collagen fibres are secreted by a cell found in the connective tissue.

Complete explanation
Option A Mast cells: Mast cells are immune cells and develop from myeloblast cells. These cells secrete chemicals known as histamine. These chemicals help the body in healing wounds, generating blood vessels. They do not secrete collagen fibres.
Option A is not correct.
Option B Macrophages: Macrophages are developed from monocytes. These are large white blood cells that play an important role in immunity. The main function of macrophages is to remove foreign substances by phagocytosis. Macrophages do not secrete collagen fibres.
Option B is not correct.
Option C Histiocytes: Histiocytes are macrophages found in the tissues. These immune cells serve the function of tissue repair and regulate inflammatory responses in our body. These cells do not secrete collagen fibres.
Option C is not correct.
Option D Fibroblasts: Fibroblasts are cells that secrete collagen fibres in the human body. These fibres provide a stable framework for the tissues. Fibroblasts take part in synthesis of the extracellular fluid. These cells also play an integral role in wound healing.
So, option D is correct.

Therefore, Option D is the correct answer.

Note:
Mast cells, macrophages, Histiocytes and fibroblasts play an important role in protecting our body from external injury. Of these, only fibroblasts are cells of the connective tissues that secrete collagen fibres to provide the body with properly structured tissues. These fibres provide strength to the tissues.