fibromuscular

Fibromuscular is an anatomical and histological term used to describe tissue that contains both fibrous connective tissue and smooth muscle. As an adjective, it indicates composition rather than naming a distinct tissue type; the relative amounts of fibrous and muscular components can vary by organ and function.

In many organs, the fibromuscular component forms a stroma or wall that provides structural support while also possessing contractile properties. The fibrous portion is primarily collagenous connective tissue, and the muscular portion consists of smooth muscle cells arranged to regulate tension and movement. This combination is common in reproductive and urinary tract structures, such as the fibromuscular stroma of the prostate, which contributes to tone and continence, and in other pelvic tissues where contractile support is needed.

In blood vessels, portions of the wall can be described as fibromuscular due to the presence of smooth muscle cells interwoven with connective tissue; however, more specific terms are typically used when pathology is present. Fibromuscular dysplasia is a distinct condition in which abnormal growth and organization of the vessel wall lead to stenosis, aneurysms, or dissection, most often affecting renal and carotid arteries.

The term derives from the Latin roots fibra (fiber) and muscularis (muscle) and is widely used in anatomical descriptions to convey a composite tissue character. See also fibromuscular dysplasia, stroma, and smooth muscle.