BACKGROUND: The evidence of hairs grouped into well-defined follicular units has given a
new vision of hair anatomy and pathology. The sebaceous glands and the arrector pili
muscle, as part of the pilosebaceous unit, should be viewed as important parts of this
organized follicular unit structure. OBJECTIVE: This study was performed to define the
morphology and the relationships between the sebaceous glands, muscles, and follicles
within the context of the follicular unit structure. METHODS: This study analyzes horizontal …