Perineum
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It has been suggested that Perineal body be merged into this article. (Discuss) Proposed since November 2014. |
| Perineum | |
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The muscles of the female perineum
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The muscles of the male perineum
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| Details | |
| Latin | Perineum, perinaeum |
| System | Musculoskeletal system |
| Perineal artery, dorsal artery of the penis and deep artery of the penis | |
| Perineal nerve, posterior scrotal nerves, dorsal nerve of the penis or dorsal nerve of clitoris | |
| Primarily superficial inguinal lymph nodes | |
| Identifiers | |
| Gray's | p.424 |
| TA | A09.5.00.001 |
| FMA | 9579 |
| Anatomical terminology | |
In human anatomy, the perineum (/pɛrəˈniːəm/;[1] Late Latin, from Greek περίνεος - perineos[2]) is a region of the body including the perineal /pɛrəˈniːəl/ body and surrounding structures. There is some variability in how the boundaries are defined.[3] According to some definitions, in females it is located between the vagina and anus and in males between the scrotum and anus.
Contents
Terminology[edit]
It is generally defined as the surface region in both males and females between the pubic symphysis and the coccyx. The perineum is the region of the body inferior to the pelvic diaphragm and between the legs. It is a diamond-shaped area on the inferior surface of the trunk that includes the anus and, in females, the vagina.[4] Its definition varies: it can refer to only the superficial structures in this region, or it can be used to include both superficial and deep structures. The perineum corresponds to the outlet of the pelvis.
It is an erogenous zone for both males and females.[5] Perineal tears and episiotomy often occur in childbirth with first-time deliveries, but the risk of these injuries can be reduced by preparing the perineum, often through massage.[6]
There are a number of American slang terms commonly used for this area of the human body, such as "gouch" and "taint".[7]
The anogenital distance is a measure of the distance between the anus and the base of the penis or vagina. Studies show that the human perineum is twice as long in males as in females.[8] Measuring the anogenital distance in neonatal humans has been suggested as a noninvasive method to determine male feminisation and thereby predict neonatal and adult reproductive disorders.[9]
Boundaries[edit]
Its deep boundaries are as follows:[10]
- in front: the pubic arch and the arcuate ligament of the pubis
- behind: the tip of the coccyx
- on either side: the inferior rami of the pubis and ischial tuberosity, and the sacrotuberous ligament
- superiorly: pelvic floor[11]
- inferiorly: skin and fascia
Triangles[edit]
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This section needs additional citations for verification. (June 2015) |
A line drawn transversely across in front of the ischial tuberosities divides the space into two triangles:
| Name | Location | Contents |
| Urogenital triangle | the anterior triangle | in females, contains the vagina |
| Anal triangle | the posterior triangle | contains the anus |
Perineal fascia[edit]
The terminology of the perineal fascia can be confusing, and there is some controversy over the nomenclature. This stems from the fact that there are two parts to the fascia, the superficial and deep parts, and each of these can be subdivided into superficial and deep parts.
The layers and contents are as follows, from superficial to deep:
- 1) Foreskin
- 2) superficial perineal fascia: Subcutaneous tissue divided into two layers: (a) A superficial fatty layer, and (b) Colles' fascia, a deeper, membranous layer.
- 3) deep perineal fascia and muscles:
| Superficial perineal pouch | Contains superficial perineal muscles: transversus perinei superficialis, bulbospongiosus, ischiocavernosus |
| Inferior fascia of urogenital diaphragm, or perineal membrane | A membranous layer of the deep fascia. |
| Deep perineal pouch | Contains the deep perineal muscles: transversus perinei profundus, sphincter urethrae membranaceae |
| Superior fascia of the urogenital diaphragm | Considered hypothetical by some modern anatomists, but still commonly used to logically divide the contents of the region. |
- 4) fascia and muscles of pelvic floor (levator ani, coccygeus)
Areas of the perineum[edit]
The region of the perineum can be considered a distinct area from pelvic cavity, with the two regions separated by the pelvic diaphragm. The following areas are thus classified as parts of the perineal region:
- Perineal pouches: superficial and deep (see above for details)
- Ischioanal fossa — a fat-filled space at the lateral sides of anal canal. It is bounded laterally by obturator internus muscle, medially by pelvic diaphragm and anal canal. Its base is the skin.
- Anal canal
- Pudendal canal — contains internal pudendal artery and the pudendal nerve.
Perineal trauma[edit]
Extensive deformations of the pelvic floor structures occur in the course of a vaginal delivery. Approximately 85% of women suffer some extent of perineal trauma during a vaginal delivery and in about 69% suturing is required.[12][13][14] Obstetric perineal trauma is a distressing event significantly contributing to postpartum morbidity and frustration of women after delivery. In many women the childbirth trauma is manifested in advanced age when the compensatory mechanisms of the pelvic floor become weakened making the problem more serious among aged population.[15][16] Perineum tactile imager to be delivered to everyday clinical practice will assist in: a) counseling patients regarding risk of childbirth trauma and recommended procedures before the delivery, and b) decision making about delivery management or obstetrical interventions to reduce a childbirth trauma.[17]
Additional images[edit]
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Diameters of inferior aperture of lesser pelvis (female)
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The perineum. The integument and superficial layer of superficial fascia reflected
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The superficial branches of the internal pudendal artery
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The posterior aspect of the rectum exposed by removing the lower part of the sacrum and the coccyx
See also[edit]
- Deep perineal pouch
- Erogenous zone
- Perineal raphe
- Intimate part
- Mula Bandha
- Pelvic floor
- Perineal tear classification
- Tactile Imaging
References[edit]
- ^ OED 2nd edition, 1989 as /pɛrɪˈniːəm/ and /pɛrɪˈniːəl/.
- ^ περίνεος, Henry George Liddell, Robert Scott, A Greek-English Lexicon, on Perseus
- ^ Федеративе Коммиттее он Анатомикал Терминологий (1998). Terminologia anatomica: international anatomical terminology. Thieme. pp. 268–. ISBN 978-3-13-114361-7. Retrieved 25 August 2010.
- ^ Gray, Henry. Anatomy of the Human Body. Philadelphia: Lea & Febiger, 1918; Bartleby.com, 2000.
- ^ Winkelmann RK. The erogenous zones: their nerve supply and significance. Mayo Clin Proc. 1959;34(2):39-47. PMID 13645790.
- ^ Shipman, M. K., Boniface, D. R., Tefft, M. E., McCloghry, F. (July 1997). "Antenatal perineal massage and subsequent perineal outcomes: a randomised controlled trial". British Journal of Obstetrics and Gynaecology 104 (7): 787–91. doi:10.1111/j.1471-0528.1997.tb12021.x. PMID 9236642.
- ^ Spears, Richard A. (2007). "Dictionary of American Slang and Colloquial Expressions" (Fourth ed.). McGraw-Hill{{inconsistent citations}}
- ^ "Validity of anogenital distance as a marker of in utero phthalate exposure". Environmental Health Perspectives 114 (1): A19–20. January 2006. doi:10.1289/ehp.114-a19b. PMC 1332693. PMID 16393642.
- ^ Michelle Welsh, et al.: "Identification in rats of a programming window for reproductive tract masculinization, disruption of which leads to hypospadias and cryptorchidism". Journal of Clinical Investigation, 13 March 2008.
- ^ perineumboundaries
- ^ Daftary, Shirish; Chakravarti, Sudip (2011). Manual of Obstetrics, 3rd Edition. Elsevier. pp. 1-16. ISBN 9788131225561.
- ^ Sleep J, Grant A, Garcia J, Elbourne D, Spencer J, Chalmers I. West Berkshire perineal management trial. Br Med J (Clin Res Ed). 1984; 289(6445): 587-90.
- ^ McCandlish R, Bowler U, van Asten H, Berridge G, Winter C, Sames L, Garcia J, Renfrew M, Elbourne D. A randomised controlled trial of care of the perineum during second stage of normal labour. Br J Obstet Gynaecol. 1998; 105(12): 1262-72.
- ^ Grant A, Sleep J. Repair of perineal trauma. In: Enkin M, Keirse MJNC, Chalmers I, Eds. A Guide to Effective Care in Pregnancy and Childbirth. Oxford: Oxford University Press, 1989: 240-43.
- ^ Barrett G, Pendry E, Peacock J, et al. Women's sexuality after childbirth: a pilot study. Archives of Sexual Behaviour 1999; 28(2): 179-91.
- ^ Tinelli A, Malvasi A, Rahimi S, et al. Age-related pelvic floor modifications and prolapse risk factors in postmenopausal women. Menopause 2010; 17(1): 204-12.
- ^ Egorov V, Kalis V, Rusavy Z. Methods and devices for biomechanical assessment of pelvic floor including perineum prior to childbirth. Filled U.S. Patent; September 23, 2014.
External links[edit]
- Perineum at The Anatomy Lesson by Wesley Norman (Georgetown University)
- Slang words for the perineum
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