What is the name of the minute involuntary muscle fiber attached to the base of the hair follicle?

The minute involuntary muscle fiber attached to the base of the hair follicle is known as the arrector pili muscle. This small muscle plays a critical role in the physical reactions the body has, such as piloerection, which is the process that causes hairs to stand erect when the muscle contracts. This response can occur in reaction to cold or emotional stimuli, creating "goosebumps."

Understanding the purpose and functioning of the arrector pili muscle is important as it reflects the body's sympathetic response to various environmental factors. The dermal papilla provides nourishment to the hair follicle, while the hair bulb is the part of the hair follicle where hair originates. The term "follicular muscle" is not commonly used in standard anatomical terminology. Recognizing these distinctions reinforces an understanding of hair follicle anatomy and function.