Quick Facts
The fibrous sheath is the outermost layer of the hair follicle.
Structure/Morphology
The connective tissue sheath of the hair follicle surrounds all structures within the hair follicle, it is the outermost layer. It is composed of fibrous tissue and is continuous with the dermis of the skin. The connective tissue sheath is separated from the external root sheath by the glassy membrane (a form of thickened basement membrane) (Standring, 2016; Young, 2006).
Function
This layer is associated with the arrector pili muscle, as it gives the smooth muscle a surface to attach too. The arrector pili muscle attaches at the site of the bulge in the external root sheath.
References
Standring, S. (2016) Gray's Anatomy: The Anatomical Basis of Clinical Practice. Gray's Anatomy Series: Elsevier Limited.
Young, B. (2006) Wheater's Functional Histology: A Text and Colour Atlas. Student consult: Churchill Livingstone/Elsevier.