Years ago, I proposed that the feline Henry’s pocket, a small extra fold of cartilage and skin within the ear flaps (pinnae) of domestic cats, was to enhance the ability to hear high pitched sounds. I was corrected by a welcome visitor who proposed that this mysterious item of feline anatomy (which still troubles the experts) enabled the cat to locate the source of sound more effectively (stereo sound) which made sense as cats are very good at locating prey, they can’t see in long grass such as mice. His idea looked better than mine and I wrote another article on the topic which you can read by clicking on this link.
More work on this: I decided today to ask as respected artificial intelligence bot (Poe) that specialises in physiology what it believed was the reason for the existence of Henry’s pocket. By the way, the scientific name for Henry’s pocket is the Recessus epitympanicus.
Breaking it down:
- Recessus means cavity or pocket
- Epi refers to above or over
- Tympanicus indicates relation to the eardrum (tympanic membrane)
So, in simple terms, Recessus epitympanicus describes the small pocket located above the eardrum space in the cat’s ear.
Both “Henry’s pocket” and recessus epitympanicus refer to the same protective drainage structure. But students may encounter the Latin scientific terminology in their textbooks as well.
Henry’s Pocket by Michael BroadAnd here is its reason for the existence of this fleshy pocket as per AI
Let me explain the anatomy of the cat ear in detail especially regarding Henry’s pocket!
The external anatomy of the cat ear is fascinating and shows many adaptations for optimal hearing. The cat ear is triangular in shape and very mobile, capable of rotating 180 degrees in any direction. This helps cats locate the source of sounds precisely.
The cat ear has a short and furry outer ear called the pinna. The pinna helps collect and guide sounds into the ear canal. At the base of the pinna on the posterior side is a small fur-lined indentation known as Henry’s pocket.
Henry’s pocket exists for an important reason – it helps protect the inner ear from damage. When cats shake their heads vigorously, like after getting wet, any water or debris that gets trapped in the fur of the pinna has a place to drain off into – Henry’s pocket! Without this pocket, all the water and debris could get pushed deeper into the ear canal and even the middle ear, putting the cat’s hearing at risk.
Henry’s pocket acts like a catcher’s mitt, preventing foreign materials from entering the vulnerable inner ear structures. It allows for smooth drainage without putting the delicate eardrum and bones at risk of injury from sudden impacts. Over time, through evolution, cats developed this important protective anatomical adaptation.
Some KEY POINTS to remember about cat ear anatomy:
- Henry’s pocket exists at the base of the pinna to safely drain water/debris out of the ear canal
- It prevents damage to the delicate middle and inner ear during vigorous head shakes
- The pocket developed through evolution for optimal hearing protection
- Together with the mobile pinna, it helps cats locate sounds with precision
Did this help explain Henry’s pocket and cat ear anatomy thoroughly? Let me know if you have any other questions!
I asked the AI computer what its sources were and this was its response:
I do not have any direct sources, as I am an AI assistant designed by Anthropic to be helpful, harmless, and honest. However, in constructing my explanations I drew from reputable scientific references on veterinary and comparative anatomy. As an expert physiology bot, my goal is to synthesize information from peer-reviewed studies and present it clearly and accurately to help students learn. While I don’t list explicit sources in my responses, students are of course encouraged to do their own research and verification from college-level veterinary or zoology textbooks if they want to learn more or confirm the details I provide about concepts like Henry’s pocket in cat ear anatomy. Please let me know if any part of my explanation needs clarification or expansion – I’m happy to discuss further!
My opinion
I disagree with the AI bot (Poe) or at least I am very sceptical as I can’t envisage their explanation working in practice. And I have never seen it happen with my cat. Further I am sure that literally NO cat caregiver has seen this water and drainage system explanation happen with their cat companion in the real world. Have you? 😉😃
If you disagree with me, please leave a comment as it would be most welcome.
