# Normal, mouth, and vaginal skin **URL:** \ **Category:** Factual Questions\ **Created:** [January 27, 2005, 5:39pm UTC](https://boards.straightdope.com/t/normal-mouth-and-vaginal-skin/286950 "2005-01-27T17:39:31Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![marshmallow](https://avatars.discourse-cdn.com/v4/letter/m/df705f/32.png) [@marshmallow](https://boards.straightdope.com/u/marshmallow)\ **Post date:** [January 27, 2005, 5:39pm UTC](https://boards.straightdope.com/t/normal-mouth-and-vaginal-skin/286950/1 "2005-01-27T17:39:31Z")
So in my biology classes we’re starting to talk about tissues. As I was reading about the different sorts of skin I stumbled upon this page that summarized every type. Here’s what it says: > [@](#): > > **Stratified Squamous Epithelium** > > _Main Locations_: Skin; mouth lining; vaginal lining > > _Functions_: Protection only; little or no absorption or transit of materials; outer layer continously sloughed off and replaced from below. > > _Description and Comments_: Several layers of cells, with only the lowest one columnar and metabolically active; division of lower cells causes older ones to be pushed upward toward surface, becoming flatter as they move. OK, from my own limited experience I can understand how mouth/vaginal lining are probably the same. But normal skin? I’ll guess I’ll just come out and say it – why is vaginal/mouth lining pinkish or light red and normal skin is, well, whatever demographic the owner belongs. The only things I can think of: 1. Some sort of pigment. 2. Oxygenated blood vessels very close to the surface. ---
**Author:** ![Nametag](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/nametag/32/406_2.png) [@Nametag](https://boards.straightdope.com/u/Nametag)\ **Post date:** [January 27, 2005, 7:11pm UTC](https://boards.straightdope.com/t/normal-mouth-and-vaginal-skin/286950/2 "2005-01-27T19:11:08Z")
Normal skin has a _stratum corneum_, a layer of keratinous tissue that protects it against damage. The internal epithelia that you mention have no such covering. The lips and other marginal areas have very thin skin. ---
**Author:** ![marshmallow](https://avatars.discourse-cdn.com/v4/letter/m/df705f/32.png) [@marshmallow](https://boards.straightdope.com/u/marshmallow)\ **Post date:** [January 27, 2005, 7:23pm UTC](https://boards.straightdope.com/t/normal-mouth-and-vaginal-skin/286950/3 "2005-01-27T19:23:11Z")
Maybe I shouldn’t say anything before reading my textbook further, but does that mean there are actual differences between mouth/vaginal and normal skin cells or do the former skins simply not form that layer until before/after they die? The skin of the vagina/mouth does slough off, right? ---
**Author:** ![chaoticbear](https://avatars.discourse-cdn.com/v4/letter/c/f07891/32.png) [@chaoticbear](https://boards.straightdope.com/u/chaoticbear)\ **Post date:** [January 27, 2005, 7:56pm UTC](https://boards.straightdope.com/t/normal-mouth-and-vaginal-skin/286950/4 "2005-01-27T19:56:27Z")
Yes, it does slough off. And, AFAIK, the skin doesn’t form that keratinized layer until the cells get closer to the top. **Nametag** used the term “stratum corneum”, so I’d listen to what he says. Damn latin words. ---
**Author:** ![marshmallow](https://avatars.discourse-cdn.com/v4/letter/m/df705f/32.png) [@marshmallow](https://boards.straightdope.com/u/marshmallow)\ **Post date:** [January 27, 2005, 8:50pm UTC](https://boards.straightdope.com/t/normal-mouth-and-vaginal-skin/286950/5 "2005-01-27T20:50:19Z")
I have to admit I wouldn’t be nearly as interested in this if it didn’t meantion vaginal lining. So the vaginal/mouth and ‘normal’ skin is identical except for the keratin which makes the skin on most of our body a harder layer. What causes the lack of this in the vagina and mouth? ---
**Author:** ![MC\_E](https://avatars.discourse-cdn.com/v4/letter/m/c77e96/32.png) [@MC\_E](https://boards.straightdope.com/u/MC_E)\ **Post date:** [January 27, 2005, 9:37pm UTC](https://boards.straightdope.com/t/normal-mouth-and-vaginal-skin/286950/6 "2005-01-27T21:37:43Z")
> [@mstay](#): > > … What causes the lack of this in the vagina and mouth? Semen? 😃 What about mucous production? I would think there must also be signifigant differences for that to occur. ---
**Author:** ![yoyodyne](https://avatars.discourse-cdn.com/v4/letter/y/a9a28c/32.png) [@yoyodyne](https://boards.straightdope.com/u/yoyodyne)\ **Post date:** [January 27, 2005, 10:32pm UTC](https://boards.straightdope.com/t/normal-mouth-and-vaginal-skin/286950/7 "2005-01-27T22:32:37Z")
> [@MC$E](#): > > Semen? 😃 No, thank you. ---
**Author:** ![chaoticbear](https://avatars.discourse-cdn.com/v4/letter/c/f07891/32.png) [@chaoticbear](https://boards.straightdope.com/u/chaoticbear)\ **Post date:** [January 27, 2005, 10:36pm UTC](https://boards.straightdope.com/t/normal-mouth-and-vaginal-skin/286950/8 "2005-01-27T22:36:37Z")
Well, squamous cells don’t produce secretions, AFAIK. I believe that all of those are done with cuboidal cells. (Shut up about goblet cells in columnar.) I think a lot of it would have to do with elasticity that’s necessary, and for less friction.