Sunt 2 tipuri de glande sudoripare:ecrine si apocrine.Glandele sudoripare apocrine se gasesc numai in axile(pop. - subsuoara), in zona organelor genitale, in jurul anusului si al mamelonului. Interesant e faptul ca ele apar la fat in luna 5 pe tot corpul dar pe urma regreseaza in afara de zonele enumerate mai sus. Glandele apocrine produc o sudoare mai vascoasa, alb-laptoasa, dar in cantitati mai reduse decat cea a glandelor ecrine. Aceasta sudoare are un miros specific, ce se datoreaza reactiei dintre transpiratie si bacteriile de la suprafata pielii. O data cu aceasta sudoare se elimina din organism nu doar apa, ci si saruri minerale si toxine rezultate din metabolismul celulelor. Secretia nu se face in mod continuu, ci intermitent, cu perioade lungi de repaus. Ea nu este influentata de temperatura mediului, ci de factori hormonali si nervosi. Glandele apocrine se dezvolta complet abia la pubertate, o data cu dezvoltarea glandelor sexuale si cu dezvoltarea caracterelor sexuale. Prin acest fapt se explica lipsa transpiratiei in axile si miros specific la copii pina la varsta pubertatii.
SpinulAlb
03-19-2007, 11:31 AM
Cand soarecele femela detecteaza feromonii unui mascul strain are loc avort spontan.
SpinulAlb
03-19-2007, 11:46 AM
Sounds odd, but it seems to be true. Researchers studying the immune systems of mice found that female mice would choose a mate whose MHC genes were the least similar to her own. MHC stands for major histocompatibility complex. These genes code for special protein markers that are attached to the surface of cells and help the body recognize whether a cell belongs to an organism or if it is an invader such as a bacteria or virus. If a cell or bacteria is identified as an invader, the body’s immune system mounts a defense to kill the intruder. Different MHC molecules are good at recognizing different invaders. By a choosing a mate whose MHC molecules are different, the female mouse is ensuring that her offspring will have a wide variety of MHC molecules that which can identify a large array of invaders and thus promote survival
Research done on human females shows that they too prefer men whose MHC genes are the least similar to their own (Richardson 1996). In an experiment, men were given an unscented T-shirt and were asked to wear it for two nights in a row. During this time they were not to use deodorants or scented soaps. Women were then presented with six shirts - three from men with similar MHC genes, and three from men with different MHC genes from their own. The results showed that the women preferred the scents of men whose MHC genes were different from their own. The scent of men with similar MHC genes often remind the women of a relative’s odor, such as a brother or father while the smells of MHC dissimilar men would often remind them of a past or current boyfriend. This suggests that body odor might have influenced past and current decisions on who to date.
It was also found that women who were taking birth control pills would often choose the T-shirts of men with similar MHC genes as smelling better. A possible explanation for this is that birth control pills trick the body into thinking its pregnant, and women on the pill often report that they prefer smells that remind them of home and relatives. Since natural preferences are reversed a woman might then be attracted to men she normally wouldn’t be - namely men with similar MHC genes