MCQ – 68647 Leave a Comment / Uncategorized / By amit18289 Question All of the following are derived from ectoderm except: A. Hair follicles B. Arrector pili C. Sebaceous glands D. Mammary gland Show Answer Correct Answer � B Explanation Ans. b. Arrector pili Arrector pili is a smooth muscle in the dermis, derived from lateral plate mesoderm. “The arrector pili is a mesodermally derived smooth muscle that lifts the hair to a nearly vertical position in a cold environment.” Share this: Share on X (Opens in new window) X Share on Facebook (Opens in new window) Facebook Like this:Like Loading…