Secretion of mammalian genitals
This article is about a secretion of mammalian genitals. For the substance that covers the skin of a baby at birth, see
Vernix caseosa
. For the experimental noise band, see
Smegma (band)
.
Smegma
(from
Ancient Greek
σμ?γμα
,
smegma
, 'soap')
[1]
is a combination of
shed
skin cells
, skin oils, and moisture. It occurs in both male and female
mammalian genitalia
. In females, it collects around the
clitoris
and in the folds of the
labia minora
; in males, smegma collects under the
foreskin
.
Females
[
edit
]
The accumulation of
sebum
combined with dead skin cells forms smegma.
Smegma clitoridis
is defined as the secretion of the
apocrine glands
of the clitoris (sweat) and the sebaceous glands of the clitoris (sebum) in combination with
desquamating
epithelial cells.
[2]
Glands that are located around the clitoris, the labia minora, and the labia majora secrete
sebum
.
If smegma is not removed frequently it can lead to clitoral adhesion which can make clitoral stimulation (such as masturbation) painful (clitorodynia).
[3]
[4]
[5]
[6]
Males
[
edit
]
In males, smegma helps keep the
glans
moist and facilitates
sexual intercourse
by acting as a lubricant.
[7]
[8]
[9]
Smegma was originally thought to be produced by
sebaceous glands
near the
frenulum
called
Tyson's glands
; however, subsequent studies have failed to find these glands.
[10]
Joyce Wright states that smegma is produced from minute microscopic protrusions of the mucosal surface of the foreskin and that living cells constantly grow towards the surface, undergo fatty degeneration, separate off, and form smegma.
[7]
Parkash
et al.
found that smegma contains 26.6% fats and 13.3% proteins, which they judged to be consistent with necrotic epithelial debris.
[10]
Newly produced smegma has a smooth, moist texture. It is thought to be rich in
squalene
[11]
and contain prostatic and seminal secretions, desquamated
epithelial cells
, and the mucin content of the
urethral glands of Littre
.
[9]
Smegma contains
cathepsin B
,
lysozymes
,
[12]
chymotrypsin, neutrophil elastase and
cytokines
, which aid the immune system.
[13]
According to Wright, the production of smegma, which is low in childhood, increases from adolescence until sexual maturity when the function of smegma for lubrication assumes its full value. From middle-age, production starts to decline and in old age virtually no smegma is produced.
[7]
Jakob Øster reported that the incidence of smegma increased from 1% among 6- to 9-year-olds to 8% among 14- to 17-year-olds (amongst those who did not present with
phimosis
and could be examined).
[14]
Clinical significance and hygiene
[
edit
]
The production of smegma, which increases during puberty, can only be of limited significance, as males and females learn to practice good genital hygiene.
[14]
Men with smegma have an elevated risk of developing
penile cancer
.
[15]
This is generally thought to be because of irritation caused by smegma, and not by the properties of smegma itself.
[15]
Other animals
[
edit
]
In healthy animals, smegma helps clean and lubricate the genitals. In veterinary medicine, analysis of this smegma is sometimes used for detection of urogenital tract pathogens, such as
Tritrichomonas foetus
.
[16]
Accumulation of smegma in the
equine
preputial folds
and the
urethral fossa
and
urethral diverticulum
can form large "beans" and promote the carriage of
Taylorella equigenitalis
, the causative agent of
contagious equine metritis
.
[17]
Some equine veterinarians have recommended
periodic cleaning of male genitals
to improve the health of the animal.
[18]
See also
[
edit
]
References
[
edit
]
- ^
"smegma"
.
Merriam-Webster.com Dictionary
. Retrieved
2017-03-02
.
- ^
"Medical Dictionary"
. Medilexicon.
- ^
Aerts, Leen; Rubin, Rachel S.; Randazzo, Michael; Goldstein, Sue W.; Goldstein, Irwin (June 2018).
"Retrospective Study of the Prevalence and Risk Factors of Clitoral Adhesions: Women's Health Providers Should Routinely Examine the Glans Clitoris"
.
Sexual Medicine
.
6
(2): 115?122.
doi
:
10.1016/j.esxm.2018.01.003
.
PMC
5960030
.
PMID
29559206
.
- ^
Rubin, Rachel; Minton, Julea; Gagnon, Catherine; Winter, Ashley; Goldstein, Irwin (April 2017). "PD25-02 Taking Responsibility for Female Prepucial Disorders: Urologic Management of Phimosis-Based Clitorodynia".
Journal of Urology
.
197
(4S).
doi
:
10.1016/j.juro.2017.02.1197
.
S2CID
78573467
.
- ^
Parada, Mayte; D'Amours, Tanya; Amsel, Rhonda; Pink, Leah; Gordon, Allan; Binik, Yitzchak M. (August 2015). "Clitorodynia: A Descriptive Study of Clitoral Pain".
The Journal of Sexual Medicine
.
12
(8): 1772?1780.
doi
:
10.1111/jsm.12934
.
PMID
26104318
.
- ^
Shafik, A. (November 2000). "The Role of the Levator Ani Muscle in Evacuation, Sexual Performance and Pelvic Floor Disorders".
International Urogynecology Journal
.
11
(6): 361?376.
doi
:
10.1007/pl00004028
.
PMID
11147745
.
S2CID
29636705
.
- ^
a
b
c
Wright J (September 1970).
"How smegma serves the penis: Nature's assurance that the uncircumcised glans penis will function smoothly is provided by smegma"
.
Sexology
.
37
(2): 50?53.
- ^
Van Howe RS, Hodges FM (October 2006).
"The carcinogenicity of smegma: debunking a myth"
.
Journal of the European Academy of Dermatology and Venereology
.
20
(9): 1046?1054.
doi
:
10.1111/j.1468-3083.2006.01653.x
.
PMID
16987256
.
S2CID
22840346
.
- ^
a
b
Fleiss PM, Hodges FM, Van Howe RS (October 1998).
"Immunological functions of the human prepuce"
.
Sexually Transmitted Infections
.
74
(5): 364?367.
doi
:
10.1136/sti.74.5.364
.
PMC
1758142
.
PMID
10195034
.
- ^
a
b
Parkash S, Jeyakumar S, Subramanyan K, Chaudhuri S (August 1973).
"Human subpreputial collection: its nature and formation"
.
Journal of Urology
.
110
(2): 211?212.
doi
:
10.1016/s0022-5347(17)60164-2
.
PMID
4722614
.
- ^
O'Neill HJ, Gershbein LL (1976). "Lipids of human and equine smegma".
Oncology
.
33
(4): 161?166.
doi
:
10.1159/000225134
.
PMID
1018879
.
- ^
Frohlich E, Schaumburg-Lever G, Klessen C (1993). "Immunelectron microscopic localization of cathepsin B in human exocrine glands".
Journal of Cutaneous Pathology
.
20
(1): 54?60.
doi
:
10.1111/j.1600-0560.1993.tb01250.x
.
PMID
8468418
.
S2CID
1326013
.
- ^
Chukwuemeka Anyanwu LJ, Kashibu E, Edwin CP, Mohammad AM (2012). "Microbiology of smegma in boys in Kano, Nigeria".
Journal of Surgical Research
.
173
(1): 21?25.
doi
:
10.1016/j.jss.2011.04.057
.
PMID
21872267
.
- ^
a
b
Oster J (April 1968).
"Further fate of the foreskin. Incidence of preputial adhesions, phimosis, and smegma among Danish schoolboys"
.
Archives of Disease in Childhood
.
43
(228): 200?3.
doi
:
10.1136/adc.43.228.200
.
PMC
2019851
.
PMID
5689532
.
The production of smegma increases from the age of 12-13, but our actual figures of the incidence of smegma can only be of limited significance, as the boys received regular instruction about preputial hygiene.
- ^
a
b
"Risk Factors for Penile Cancer"
.
American Cancer Society
. 25 June 2018.
- ^
Chen XG, Li J (2001). "Increasing the sensitivity of PCR detection in bovine preputial smegma spiked with
Tritrichomonas foetus
by the addition of agar and resin".
Parasitology Research
.
87
(7): 556?558.
doi
:
10.1007/s004360100401
.
PMID
11484853
.
S2CID
7671511
.
- ^
Primary Industries Ministerial Council of Australia and New Zealand (2002).
Disease strategy: Contagious equine metritis
Archived
2008-07-21 at the
Wayback Machine
(Version 1.0). In: Australian Veterinary Emergency Plan (AUSVETPLAN), Edition 3, PIMCANZ, Canberra, ACT.
- ^
Lowder, Michael (1 September 2001).
"A Clean Sheath Is A Healthy Sheath"
.
Horse City
. Archived from
the original
on 14 September 2005.
External links
[
edit
]
Wikimedia Commons has media related to
Smegma
.
- Neubert, U; Lentze, I (March 1979). "Die bakterielle Flora des Praputialraumes" [The bacterial flora of preputial space].
Hautarzt
(in German).
30
(3): 149?153.
PMID
35486
.
- Marzuillo, Pierluigi; Guarino, Stefano; Furlan, Daniela; Pecoraro, Anna; Pedulla, Marcella; Miraglia del Giudice, Emanuele; La Manna, Angela (October 2018). "Cleaning the genitalia with plain water improves accuracy of urine dipstick in childhood".
European Journal of Pediatrics
.
177
(10): 1573?1579.
doi
:
10.1007/s00431-018-3215-x
.
PMID
30054720
.
S2CID
51726930
.
- Fahmy, Mohamed A. Baky (2020). "Smegma".
Normal and Abnormal Prepuce
. pp. 153?161.
doi
:
10.1007/978-3-030-37621-5_17
.
ISBN
978-3-030-37620-8
.
S2CID
243171662
.