Where are hair follicles, sebaceous glands, and ceruminous glands located?

The presence of hair follicles, sebaceous glands, and ceruminous glands is characteristic of the lateral one-third of the external auditory canal. This specific part of the ear is lined with skin that contains these structures, which play distinct roles in ear health and maintenance.

Hair follicles can help trap debris and prevent it from entering deeper into the ear canal. Sebaceous glands produce sebum, an oily substance that helps lubricate the skin and can provide a barrier against microbial invasion. Ceruminous glands specifically produce cerumen, or earwax, which serves to trap dust and other foreign particles, keeping the ear canal clean and providing antimicrobial properties.

The inner ear does not contain these structures, as it is involved primarily in hearing and balance functions and is lined with sensory cells rather than skin with glands. The medial one-third of the external auditory canal does not contain these glands either, as it transitions into the area where tissues change and undergo different functional adaptations. The outer ear encompasses more than just the lateral one-third of the external auditory canal and is not a precise location for the specified glands and follicles. Thus, identifying the lateral one-third of the external auditory canal as the correct location for these anatomical features is accurate.