Overview

Like dense regular connective tissue, it is dominated by coarse type I collagen with relatively few fibroblasts and little ground substance, but its bundles run in various planes, forming a felt-like meshwork that withstands stretching in multiple directions. Some elastic fibres are present.

It forms the reticular layer of the dermis (where it gives skin its strength and is the source of leather), the fibrous capsules of organs such as the kidney, liver, spleen, lymph nodes and testis (tunica albuginea), the outer fibrous layer of the periosteum and perichondrium, joint capsules, the dura mater, the sclera and the submucosa of parts of the digestive tract.

Location: Reticular dermis; capsules of organs and joints; periosteum; perichondrium; dura mater; sclera; heart valves' fibrous layer; submucosa.

Anatomy

Histology: Thick pink collagen bundles cut in various planes (longitudinal, oblique, transverse) with sparse fibroblast nuclei.

Function

Resists multidirectional tension.
Forms protective capsules and sheaths.

Clinical significance

Keloids and hypertrophic scars

Excessive deposition of collagen during dermal healing: hypertrophic scars stay within the wound borders and may regress; keloids extend beyond them, recur after excision and are more common in people with darker skin; they contain thick, hyalinised bundles of type I and III collagen.

Systemic sclerosis

Fibroblast activation produces excessive collagen in the dermis and internal organs → skin tightening, Raynaud phenomenon, pulmonary fibrosis, renal crisis.

Compiled from standard anatomy and physiology references — see the Cells & Tissues sources. For education only; not medical advice.