Perineum and Perineal body
- Perineum.
- Perineal body.
Perineum
Perineum definition:
the area between vaginal orifice & anus.
Perineum divisions:
it is divided into 2 triangles by a line
between 2 ischial spines:
i. Anterior triangle (urogenital triangle).
ii. Posterior triangle (anal triangle).
Perineum classification:
i. Anatomical perineum (true perineum):
• Diamond- shaped, pelvic outlet & soft structures
cover it.
ii. Gynecological perineum:
• Area between posterior commisure & anus.
Perineal body
Perineal body development:
mesodermal (lower part of anorectal septum).
Description:
Def.: central tendon of the perineum.
Position: pyramidal fibromuscular mass that:
• Lies in midline between anal canal posteriorly & lower vagina anteriorly.
• Its base extends from fourchette to the anus & covered by skin.
Size: each side of the triangle = 3.5 cm.
Muscles attached to it:
1. Bulbocavernosus.
2. Superficial transverse perineii.
3. Deep transverse perineii.
4. External anal sphincter.
5. Some fibers of levator ani.
Perineal body blood supply:
A. Arterial: pudendal arteries (arise from internal iliac artery).
B. Venous: pudendal veins (drain into internal iliac vein).
Perineal bodynerve supply:
perineal branch of pudendal nerve.
Perineal bodylymph drainage:
Inguinal & external iliac L.Ns.
Perineal bodyfunctions:
1. Support pelvic viscera.
2. Support urethra& urethra-vesical junction.
3. Assists in defecation & childbirth.
Applied notes:
1) Prolapse.
2) Stress incontinence.
3) Perineal tear during labour:
Aetiology: *overstretch of perineum e.g. large fetal head.
*Rapid stretch of the perineum e.g. precipitates labour.
*Inelastic perineum e.g. primigravida.
Types: complete & incomplete.
Treatment: immediate repair within 24 hours.
Perineum and perineal body videos:
Muscles of the perineum video
Basics or performing a perineal body repair video
See also: Anatomy of pelvic floor