Skene’s glands

Skene’s glands, also known as the paraurethral glands, are small glands located on either side of the urethral opening in females. They are positioned near the anterior wall of the vagina, just inside the vaginal opening, surrounding the lower end of the urethra. These glands are embedded in the tissue of the vaginal wall and are sometimes referred to as the female equivalent of the male prostate due to their similar function and structure. Skene’s glands open into the urethra and the area near the urethral meatus, contributing to the fluids in this region. They are not visible externally but are vital to the female genital system.

Structure and Anatomy

Skene’s glands, also known as the paraurethral glands, are small but significant structures within the female reproductive system. Below is a detailed explanation of their anatomy.

Location and Position

Skene’s glands are located near the anterior wall of the vagina, surrounding the lower portion of the urethra. These glands are situated on either side of the urethral meatus (the external opening of the urethra), embedded in the soft tissue of the vaginal wall.

• Proximity to the Urethra: Skene’s glands are positioned very close to the urethra and are sometimes described as the female equivalent of the prostate gland. They are located in the periurethral zone, directly adjacent to the urethra’s distal portion.
• Openings: Each Skene’s gland has a small duct that opens into the urethral canal and may also open into the vestibule near the urethral meatus. These ducts are microscopic, and the openings are not visible to the naked eye.

Size and Structure

Skene’s glands are relatively small, typically measuring just a few millimeters in size. Their size and structure can vary slightly among individuals, but they remain consistent in their general form and function.

• Glandular Tissue: The glands are composed of tubuloalveolar glands, which are exocrine in nature, meaning they release their secretions into ducts rather than directly into the bloodstream. The cells lining the glands are primarily cuboidal to columnar epithelial cells that produce the glandular fluid.
• Duct Structure: The ducts of Skene’s glands are narrow, tube-like structures that lead from the gland to the urethra or nearby vestibule. These ducts allow the secretions produced by the glands to enter the urethral canal or the area around the urethral opening.

Blood Supply

The blood supply to Skene’s glands is provided by branches of the internal pudendal artery, which is the main artery supplying blood to the external genitalia and perineal structures.

Vascularization: The rich blood supply ensures that the glands receive the necessary oxygen and nutrients to produce their secretions. Blood flow is also essential for the gland’s function, especially during periods of increased activity such as sexual arousal.

Nerve Supply

Skene’s glands are innervated by branches of the pudendal nerve, which is the primary nerve for the external genitalia.

• Sensory Nerves: The nerve supply to Skene’s glands plays an essential role in the regulation of their function. Although the glands themselves are not typically highly sensitive, the surrounding tissue has rich sensory innervation, contributing to the overall sensation in the area during sexual arousal.
• Autonomic Nervous System: The glands are also innervated by the autonomic nervous system, which controls the secretion of fluids from these glands. Parasympathetic stimulation is responsible for triggering the secretion of fluid from Skene’s glands during sexual arousal.

Lymphatic Drainage

Lymphatic drainage from Skene’s glands is directed primarily to the superficial and deep inguinal lymph nodes. These lymph nodes are located in the groin region and help filter lymphatic fluid from the surrounding areas.

Role in Immune Defense: Proper lymphatic drainage is crucial for maintaining the health of Skene’s glands and preventing infections by allowing immune cells to clear pathogens or harmful particles from the region.

Histological Structure

The histological makeup of Skene’s glands is similar to other exocrine glands in the body.

Epithelial Lining: The ducts and glands are lined by cuboidal to columnar epithelial cells. These cells are responsible for secreting fluid into the urethra or vestibule. The glandular epithelium is involved in producing secretions that are released during sexual arousal or other physiological activities.

Secretory Cells: Skene’s glands have secretory cells that are designed to produce fluid. These cells contain organelles such as the endoplasmic reticulum and Golgi apparatus, which are involved in the synthesis and transport of the glandular fluid.

Embryological Development

Skene’s glands develop from the same embryological tissues that form the urogenital sinus, the same structure from which the urethra and parts of the external genitalia develop.

Homology with Male Prostate: Skene’s glands are considered homologous to the male prostate gland, meaning they arise from the same embryological origins and serve a similar function. Just as the prostate gland produces secretions that are involved in the reproductive process, Skene’s glands produce fluids that contribute to the overall functioning of the female reproductive system.

Relationship to Surrounding Structures

Skene’s glands are closely associated with several nearby anatomical structures:

• Urethra: The glands are located along the length of the urethra, contributing secretions directly into the urethral canal. Their proximity to the urethra makes them an integral part of the periurethral anatomy.
• Vestibule: Skene’s glands are situated near the vestibule of the vulva, the area that contains the openings of the urethra and vagina. Some ducts from Skene’s glands open directly into the vestibule, contributing to the fluids present in this area.
• Anterior Vaginal Wall: The glands are also located near the anterior wall of the vagina, adding to their importance in the structural integrity of the anterior part of the vaginal canal.

Histological Variability

The size and activity of Skene’s glands can vary significantly depending on the individual and hormonal influences.

Hormonal Influence: Estrogen plays a role in the activity and secretion from Skene’s glands. Hormonal changes that occur during puberty, the menstrual cycle, pregnancy, and menopause can affect the size and function of these glands.

Comparison with Other Glands

Skene’s glands are part of a broader network of glands within the female genitalia, each serving different roles in secretion and lubrication.

Comparison with Bartholin’s Glands: While Skene’s glands are responsible for secreting fluid into the urethra or near the urethral opening, Bartholin’s glands are larger and located near the vaginal opening, where they provide lubrication to the vulva during sexual arousal. Both sets of glands play distinct but complementary roles in female genital function.

Function

Skene’s glands, also known as the paraurethral glands, play important roles in female genital function, including lubrication, secretion, and contributing to the female sexual response. Below is a detailed breakdown of their functions.

Secretion of Lubricating Fluid

One of the primary functions of Skene’s glands is to secrete a fluid that helps lubricate the urethral opening and the surrounding vaginal area.

• Production of Mucus: Skene’s glands produce a clear, mucus-like fluid that is released through ducts that open into the urethra or near the urethral meatus. This fluid helps maintain moisture in the vaginal vestibule and around the urethral opening, ensuring these areas remain lubricated, especially during sexual arousal or urination.
• Reduction of Friction: The secretion from Skene’s glands reduces friction around the urethral opening, preventing irritation of the sensitive tissues during physical activities such as sexual intercourse or urination. This lubrication is essential for the comfort and health of the genital area, minimizing the risk of irritation or infection.

Contribution to Female Ejaculation

Skene’s glands are thought to play a significant role in the phenomenon of female ejaculation, though this is a subject of ongoing research and debate.

• Ejaculate Fluid Production: In some women, Skene’s glands produce fluid that is expelled during orgasm, contributing to female ejaculation. This fluid is believed to be similar in composition to prostatic fluid, which is produced by the prostate gland in males. Like the male prostate, Skene’s glands produce fluid rich in enzymes, including prostatic-specific antigen (PSA) and prostatic acid phosphatase (PAP), both of which are present in female ejaculate.
• Discharge During Orgasm: The glands are thought to release this fluid during sexual climax as part of the female sexual response. The amount of fluid expelled varies greatly between individuals, and not all women experience noticeable female ejaculation. However, for those who do, Skene’s glands are believed to be the primary source of the ejaculate fluid.

Antimicrobial Defense and Urethral Protection

Skene’s glands produce secretions that may help protect the urinary tract from infection.

• Antimicrobial Properties: The fluid secreted by Skene’s glands contains antimicrobial compounds that help protect the urethra and surrounding tissues from bacterial infections. This protection is crucial in maintaining the health of the urinary tract, especially since the urethra is in close proximity to the vaginal opening, where bacteria may be introduced.
• Flushing Out Pathogens: By secreting fluid into the urethral opening, Skene’s glands may help flush out minor contaminants or bacteria that could otherwise enter the urethra and cause infections such as urinary tract infections (UTIs). The lubrication provided by the glands creates a moist environment that is less conducive to bacterial growth, contributing to the overall health of the genital region.

Contribution to Sexual Pleasure

Skene’s glands are involved in enhancing sexual pleasure through lubrication and tactile feedback.

• Enhancing Sensitivity: The glands themselves are located near the anterior wall of the vagina and the urethra, both of which are areas with high sensitivity. During sexual arousal, the secretion of fluid from Skene’s glands enhances lubrication, reducing friction and making sexual activity more comfortable and enjoyable.
• Indirect Stimulation: The proximity of Skene’s glands to the G-spot (an area located on the anterior vaginal wall that is believed to be a source of sexual pleasure for some women) suggests that stimulation of this region may indirectly stimulate the glands. This stimulation can contribute to increased lubrication and, in some cases, female ejaculation, adding to the overall sexual experience.

Urethral and Vestibular Moisture Maintenance

Skene’s glands play a key role in maintaining the moisture levels in the urethral opening and the surrounding tissues of the vulva.

• Moistening the Urethral Meatus: By secreting mucus-like fluid into the urethral meatus, Skene’s glands help keep the opening of the urethra moist, preventing dryness and irritation. This moisture is essential for maintaining the comfort of the urethral opening during activities such as urination or sexual intercourse.
• Support for Vestibular Health: The vestibule, which includes the openings of the urethra and vagina, benefits from the lubrication provided by Skene’s glands. This lubrication reduces the risk of skin irritation or damage, particularly during sexual activity, when friction is more likely.

Hormonal Response and Secretion Regulation

The function of Skene’s glands is influenced by hormonal changes, particularly during puberty, the menstrual cycle, and sexual arousal.

• Response to Estrogen: Estrogen plays a significant role in regulating the activity of Skene’s glands. During puberty, increased estrogen levels stimulate the development and function of the glands, leading to increased secretion. Similarly, during ovulation, when estrogen levels are at their peak, the glands may become more active, contributing to an increase in vaginal and urethral moisture.
• Secretion During Sexual Arousal: During sexual arousal, the autonomic nervous system triggers increased secretion from Skene’s glands. This increase in fluid production helps prepare the vaginal and urethral areas for intercourse by providing additional lubrication and reducing the risk of friction or discomfort.

Role in Female Reproductive Health

Though small, Skene’s glands contribute to the overall health of the female reproductive system by maintaining a balanced environment in the genital and urinary areas.

• Supporting a Healthy Urogenital Environment: Skene’s glands produce fluids that help maintain the moisture and cleanliness of the urethra and vulvar vestibule, supporting a healthy urogenital environment. The secretions from the glands help flush out harmful microorganisms and keep the area free from irritation and infection, contributing to overall reproductive health.
• Regulation of Fluid Balance: By regulating the fluid levels around the urethral opening and vestibule, Skene’s glands play a part in maintaining the balance of moisture in the external genitalia, which is essential for both sexual health and day-to-day comfort.

Supporting Vaginal Health

Although Skene’s glands are located near the urethra, they also contribute indirectly to the health of the vagina by maintaining moisture and facilitating lubrication.

• Prevention of Vaginal Dryness: By contributing to the overall lubrication of the vaginal vestibule, Skene’s glands help prevent vaginal dryness, particularly during sexual activity. This function is especially important for women who experience reduced lubrication due to hormonal changes, such as during menopause.
• Barrier to Infection: The fluids secreted by Skene’s glands create a moist environment that helps maintain the health of the vaginal area. This lubrication acts as a barrier to infection, preventing the buildup of harmful bacteria and reducing the risk of conditions such as vaginitis or urinary tract infections.

Clinical Significance

Skene’s glands, though small, are clinically significant due to their role in female reproductive and urinary health. Infections or blockages of the Skene’s glands can result in conditions such as Skene’s gland cysts or abscesses, which may cause pain, swelling, and discomfort near the urethral opening. In rare cases, these infections can lead to urethritis (inflammation of the urethra) or may spread to surrounding tissues.

Skene’s glands are also believed to play a role in female ejaculation, and their secretions contain compounds similar to those produced by the prostate gland in men, such as prostate-specific antigen (PSA). In rare cases, Skene’s gland adenocarcinoma, a type of cancer, can develop, necessitating early diagnosis and treatment. Awareness of the health of Skene’s glands is important for maintaining female urogenital health, preventing infections, and managing related conditions.