This article presents information about the different body fluids that a woman's body produces during sexual activities, or that play a part in these activities.
"Vaginal secretions contain many things, including sweat, sebum, and secretions from Bartholin's and Skene's glands at the vulva, endometrial, and oviductal fluids (which change with the menstrual cycle), cervical mucus, exfoliated cells, and secretions of the vaginal walls themselves, which increase with sexual arousal. All women's vaginal secretions include pyridine, squalene, urea, acetic acid, lactic acid, complex alcohols (including cholestrol), glycols (including propylene glycol) ketones, and aldehydes.
"But a more detailed chemistry of the acids in vaginal secretions separates women into two groups. All women produce acetic acid, but one third of them produce short-chain aliphatic acids as well. The short-chain aliphatic acids, which include acetic, propionic, isovaleric, isobutyric, propanoic, and butanoic acids, are a pungent class of chemicals which other primate species produce as sexual-olfactory signals. Although no one has yet proven the acids' role in the mating behavior of humans, some researchers have referred to them [as] "copulins" and "human pheromones.
"Like the volatile acids produced on the skin, the vagina's aliphatic acids come from the metabolic processes of resident bacteria, including Lactobacilli, Streptococci, and Staphylococci. For all women, the acid content varies with the menstrual cycle, rising from day one after menstruation and peaking mid-cycle, just before ovulation. The amounts vary more dramatically in the acid producers, however, and one study, whose authors describe their subjects as "young, healthy, and members of the socioeconomic class that attends a privately endowed university," determined that people can reliably smell changes in an acid-producing woman's vaginal secretions over the course of her cycle, but not in the secretions of non-acid producers. "
The following illustrations show us where the vulvar, vaginal, cervical, and uterine fluids originate.
"Sebum, skin oil, functions to reduce moisture loss through our skin, protect it from infection, and lubricate it in contact areas. It also makes hair shiny and waterproof and helps generate scents. Sebaceous glands occur all over the skin, except for the palms and soles, and are largest and most numerous on the back, forehead, face, ears, genitals, and anal region. Most connect to hair follicles, but some, such as the Meibomian glands (in the eyelids), Tyson's glands (in the foreskin), and the sebaceous glands around the nipples and along the edge of the upper lip, empty directly onto the surface of the skin. On some people, you can see the ones along the lip as pale yellow specks, or "Fordyce's spots."
"Sebum consists of 57.5% glycerides and free fatty acids, 26% wax esters, 12% squalene, 3% cholesterol esters, and 1.5% cholesterol, but despite its fatty waxy content, sebum production does not correlate with dietary fat intake. However, it does correlate with levels of testosterone and other androgens. Men produce more sebum than women and prepubertal boys, and uncastrated men produce more than eunuchs. Male sebum production increases fivefold during puberty, causing acne. But interestingly, newborns secrete sebum at adult levels for a short time after birth, and women secrete greater amounts during pregnancy and lactation."
"Body surface odors come from microbial breakdown of sweat, sebum, and scaled-off skin cells. Different bacterial digest these materials into different sets of chemicals. Meanwhile, the mixture of bacteria species varies over different body regions. As a result, the odor-determining chemical mixtures produced on the skin of different parts of the body also vary.
"Especially strong scents will come from any areas where these desquamated epithelial cells can build up, such as on scalps, under toes-nails, in navels, and under foreskins. In these places, the bacteria have a feast, generating hefty quantities of local odorants.
"Substances such as smegma and toe cheese, then, are a mixture of skin secretions and dead cells, along with the bacteria that lives off of them and the cheesy, cabbage-y, and fishy-selling waste products they produce as a result."
"The adult body contains from two to four million sweat glands, at densities of around one to two hundred per square centimeter of skin. Together, they typically put out from one to three quarts of perspiration per day, although a day of exertion and thirst-quenching in the heat can make a body sweat out fifteen quarts or more.
"Most of our sweat glands are eccrine glands, the salt-retaining cooling sweat glands, most prevalent on the back, chest, forehead, palms, and soles. But we have another, older type of sweat gland, apocrine, which helps produce scents used for personal identification and mating. These scent glands concentrate most highly in the underarms, but also surround the nipples, genitals, and anus, and as many have noticed, they respond to stress. Apocrine sweat contains an odor resembling musk, a substance secreted as a scent by deer and other animals and used in perfume. This has led some observers to remark that our toilet ritual has us wash away our own sweat and substitute the sweat of deer. An experiment conducted at International Flavors and Fragrances in New York showed that women who sniff musk develop shorter menstrual cycles, ovulate more often, and conceive more easily.
"Apocrine sweat has no odor when it arrives on the skin surface, but it is immediately broken down by bacteria, including Staphylococcus epidermis (the most prevalent), S. saprophyticus (more prevalent in winter), S. aureus (more prevalent in summer), Escherichia coli, and various species of Corynebacteria, Brevibacteria, Propionibacteria (more prevalent in men), Enterobacter, Klebsiella, and Proteus. These flora generate compounds such as androstenone ("stale urine" smell), androstenol (nice "musky" odor), and isovaleric acid (sweaty or "goatlike" smell)."
Quoted text from the book The RE/Search Guide to Body Fluids by Paul Spinrad. Copyright 1994 by RE/Search Publications. ISBN 0-940642-28-X
Apocrine: Oil producing glands that populate the hair covered areas of the body; they become active during puberty. They are located at the base of hair follicles. Responsible for the strong odors associated with sweating.