Download Pelvis + Perineum

The
Perineum
What is the perineum?
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Corresponds to the outlet of the pelvis
bounded by the pubic symphysis, coccyx,
ischial tuberosities, pubic rami, ischial rami
contains anus
in male (root of scrotum, penis)
in female (vulva- mons pubis, labia majora
and minora, clitorus, hood of clitorus]
MALE PERINE
SUPERFICIAL PERINEUM IN
FEMALE
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1)vulva.
2)mons pubis.
3)clitoris .
4)hood of clitoris.
5)labia majora .
6)labia minora.
Bony Pelvis
Moore et al; Fig. 3.3
Netter 334
Urethral hiatus
Puborectalis m.
Iliococcygeus m.
Anorectal hiatus
Tendinous arch
Obturator internus m
Pubococcygeus m.
Piriformis m.
(Ischio)coccygeus m.
Plate 340
Urethra
Puborectalis m.
Pubococcygeus m.
Iliococcygeus m.
(Ischio)coccygeus m.
Plate 341
Gluteus maximus m.
Pubococcygeus m.
Iliococcygeus m.
Urethra
Vagina
Rectum
Tendino
Piriform
(Ischio)coccygeus m.
Plate 338
Urethra
Vagina
Pubococcygeus m.
Obturator internus m.
Puborectalis m.
Iliococcygeus m.
Plate 339
(Ischio)coccygeus m.
Sacrotuberous ligament
Piriformis m.
Obturator internus m.
Tendinous arch
Iliococcygues m.
(Ischio)coccygues m
Rectum
Pubococcygeus m.
Urethra
Vagina
Plate 338
Levator Ani
Consists of three parts – the pubococcygeus,
the puborectalis and the iliococcygeus.
Origin :- from the body of the pubis, the tendinous
arch of the obturator fascia and the ischial spine.
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Insertion:- the perineal body, the coccyx, the
anococcygeal ligament, the walls of the prostate
or vagina, the rectum and the anal canal.
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Innervated by the nerve to levator ani from S4
and the inferior rectal nerve ( S2-S4) and the
coccygeal plexus
Function:-1)support the pelvic viscera
2) they raise the pelvic floor
3)assist the abdominal muscles in forced
expiration activities
Urogenital Diaphragm
The outlet of the pelvis is spanned by two muscular
sheets - a deeper "pelvic diaphragm" and a more
superficial "urogenital diaphragm." The pelvic
diaphragm forms the floor of the pelvic cavity, and
the urogenital diaphragm fills the space within the
pubic arch. The muscles of the male and female
urogenital diaphragm include the following: (1)
"superficial transversus perinei," a small bundle of
muscle fibers that pass along the back border of the
urogenital diaphragm and assists other muscles in
supporting the pelvic tissues;
Urogenital Diaphragm
(2) the "bulbospongiosus" muscles, which are united
and surround the base of the penis; (3) the
"ischiocavernosus muscle," a tendinous structure that
extends down to the margin of the pubic arch and
assists the function of #2; and (4) the "sphincter
urethrae" are muscles that arch around the urethra
and unite with those on the other side. Together they
act as a sphincter that closes the urethra by
compression and opens it by relaxation to control the
flow of urine.
Perineum
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Two Triangles
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Anal triangle (posterior) contains the anus
Urogenital triangle (anterior) contains the root of the
scrotum and penis in males or the external genitalia in
females
The perineal membrane stretches between the
two sides of the pubic arch and covers the
anterior part of the outlet
The perineal body is an irregular fibromuscular
mass located between the anal canal and the
perineal membrane
Muscles Inferior to the Pelvic Floor:
The Urogenital Diaphragm
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Muscles inferior to the pelvic floor
Stretches between two sides of the pubic
arch in the anterior half of the perineum
Contains
• Deep transverse perineal muscle
• External urethral sphincter muscle
The ischiocavernosus and
bulbospongiosus assist in erection of the
penis and clitoris; lie superficial to the
urogenital diaphragm
Muscles of the Pelvic Floor
Figure 10.12b
Female Urethra
Female Urethra
Triangles
Perineal Body
Perineal Membrane
Perineum-Female
Perineum - Male
Perineum
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Muscles
Bulbospongiosus – F O: central tendon of
perineum, M O: central tendon of perineum
and bulb of penis; F I: dorsum of clitoris,
urogenital diaphragm, M I: root of penis; A:
compress vagina orifice or compress urethra,
N: perineal nerve, pudenal nerve
Ischiocavernosus – O: ramus of ischium, I:
near pubic symphysis, maintains erection of
penis or clitoris
Muscles - Female
Muscles - Female
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Sup.perineal pouch :1)crura of penis .
2)bulb of penis.
3)bulbs of vestibule.
4)ischiocavernosus.
5)bulbospongiosus.
6)perineal branch of pudendal nerve.
7)perineal body.
8)superficial transversus perinie muscle.
9)greater vestibular glands(Bartholin)
Deep perineal pouch:
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1)membranuous part of urethra.
2)deep transversus perinie muscle.
3)int.pudendal artery.
4)Bulbourethral glands.
5)dorsal nerve of penis.
6)sphinecter urethrae muscle.
Muscles – Male
Muscles - Male
Superficial Transverse Perineal
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O: Ischial tuberosity
I: Perineal body
A: Support perineal body
N: Pudenal nerve
External Urethral Sphincter
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O: Ischial tuberosity
I: surround urethra
A: compress urethra to maintain urine
continence
N: Pudenal (S2-S4)
Superficial Transverse Perineal
F
Superficial Transverse Perineal
F
Superficial Transverse Perineal
M
Deep Transverse Perineal
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O: Medial Aspect of Ischial Ramus
I: Pineal Body
A: Stabilizes position of the perineal
body
N: Pudenal N (S2-S4)
Deep Transverse Perineal - F
Deep Transverse Perineal -M
Deep Transverse Perineal - M
Deep Transverse Perineal M
Superficial Perineum Female
Superficial Perineum Male
Female Peritoneum
Male Peritoneum
Male Urethra
Male Urethra
Perineal Body
At perineal body, the following muscles
converge and are attached:
External anal sphincter
Bulbospongiosus
Superficial transverse perineal muscle
Anterior fibers of the levator ani
fibers from external urinary sphincter
Deep transverse perineal muscle
Perineal n.
Dorsal n. of clitoris
Pudendal ner
Inferior rectal nn.
Plate 393
Perineal a.
Internal pudend
Inferior recta
Plate 384
Posterior scrotal n
Perineal n.
Pudendal n.
Inferior rectal a
Inferior rectal nn.
Fascia of obturator internus m. forming pudendal canal
Plate 391
Perineal a. and v.
Inferior rectal v.
Pudendal canal
Inferior rectal a.
Plate 385