Connective Tissue Fibres | Collagen | Elastin | Human Histology | Collagen Biochemistry

Introduction to Connective Tissue Fibres00:00:00

Connective tissue supports and binds structures using an extracellular matrix consisting of ground substance and three primary protein fibers: collagen, reticulin, and elastin.

Collagen Types and Functions00:01:16

Collagen is the most abundant protein in the body. Type I is found in bone and tendons, Type II in cartilage and the eye, Type III (reticular fibers) in lymphoid organs, and Type IV in the basement membrane.

Collagen Synthesis and Structure00:03:41

Collagen is formed by three alpha chains in a triple helix. Synthesis involves transcription, translation, and post-translational modifications like hydroxylation—which requires vitamin C—and glycosylation within the endoplasmic reticulum.

Formation of Collagen Fibrils00:07:26

Procollagen is secreted and cleaved into insoluble tropocollagen, which spontaneously assembles into staggered fibrils. Lysyl oxidase provides essential cross-linking for stability.

Elastin Properties and Comparison00:08:47

Elastin provides elasticity to tissues like the lungs and skin. Unlike collagen, it lacks a triple helix structure and uses desmosine cross-links. Fibrillin defects, which form a scaffold for elastin, are associated with Marfan's syndrome.