The stapes, also known as the stirrup, is the innermost ear ossicle and the only bone in the human body that remains the same size from birth until death.
Understanding the Stapes
The stapes is one of three tiny bones located in the middle ear. These bones – the malleus (hammer), incus (anvil), and stapes (stirrup) – transmit sound vibrations from the eardrum to the inner ear. While the other bones in the body grow and change throughout a person's life, the stapes maintains its original size. This is due to its unique structure and function within the delicate auditory system.
References: One source explicitly states: "The only part of the human body which does not grow in size from birth to death is the innermost ear ossicle or the 'Stapes'." (Source: Reference provided – date: 06-May-2022).
Other Body Parts and Growth
It's important to note that many sources discuss the relative growth of different body parts. While the stapes remains the same size, other parts may appear to remain the same size proportionally to the overall body's growth. For example, some sources mention eyes as reaching full size early in life. However, these body parts still undergo cellular processes like renewal and regeneration.
- Eyes: While eye size remains relatively constant after infancy, the cells within the eye are continually replaced and renewed. (Source: https://birthworks.org/do-human-eyes-remain-the-same-size-from-birth-to-death-by-cathy-daub-cce-cd-bwi/)
- Teeth: Although teeth do not increase in size after eruption, they undergo significant wear and tear throughout life.
The key distinction is that the stapes' structural integrity and size remain unchanged from birth to death, unlike these other parts which undergo cellular changes and/or physical wear.
