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Station 3: Female Perineum
Complete anatomy
Female perineum
Question
What are the boundaries of the perineum? What are its triangles called? (See Figure 18.)
This station covers the female urogenital (UG) triangle. The anal triangle has a similar construction in both sexes—it is covered at Station 2.
- The UG triangle contains: (1) the external genitalia (vulva) and (2) two fascia-lined spaces: superficial and deep perineal pouches.
- The external genitalia (vulva) are located on the surface of the UG triangle.
External Genitalia (Vulva)
Identify these on an undissected donor and models:
Mons pubis
Labia majora
Pudendal cleft (the space between the labia majora)
Labia minora
Superiorly, the labia minora split into two parts around the clitoris:
Prepuce of clitoris (fusion of labia minora above the clitoris— forms a “hood” over the clitoris)
Frenulum of clitoris (fusion of the labia minora below the clitoris)
Frenulum of the labia minora = the union of the two labia minora inferiorly (clinicians call this the Fourchette)
Clitoris: Crura, body and glans (the body is under the prepuce, the crura are attached to the ischiopubic rami—see Figure 21)
Vestibule (the cavity between the labia minora)—Within the vestibule are these openings:
External urethral orifice
Vaginal orifice (aka = Introitus)
Superficial Perineal Pouch
Review of boundaries:
- Floor: Superficial perineal fascia (Colle’s Fascia)
- Roof: Perineal membrane (a robust layer of deep fascia)
- Lateral: Ischiopubic rami
- Anterior (apex of triangle): Pubic symphysis
- Posterior (base of triangle): Line between ischial tuberosities—the fascias of the UG triangle fuse here
Contents of the female superficial perineal pouch (donor and models):
Bulbs of the Vestibule—paired, elongated erectile bodies on each side of the vaginal orifice
Greater vestibular (Bartholin’s) glands—lie on each side of the vestibule at 4:00 and 6:00 positions – their ducts empty into the vestibule adjacent to the vaginal orifice. What is their function?
Ischiocavernosus muscles—cover the crura of the clitoris (erectile tissue)
Bulbospongiosus muscles—cover the bulbs of the vestibule (erectile tissue)
Superficial transverse perineal muscles
Note
[Muscles in the UG triangle are not well developed in most donors.]
Although it is on the border between the UG and anal triangles, identify the location of the perineal body.
Question
Why is the perineal body a structurally important landmark? It is larger and clinically more important in females.
Checklist, Lab #14
Checklist items at each of the five stations are indicated by checkboxes.
