Pelvis + Perineum
Pelvic Cavity
 Enclosed by bony, ligamentous and
muscular wall
 Contains the urinary bladder, ureters, pelvic
genital organs, rectum, blood vessels,
lymphatics and nerves
 Pelvic inlet (superior pelvic aperture)
 Pelvic outlet (inferior pelvic aperture)
Superior Apeture
Inferior Pelvic Border
Bony Pelvis
 Innominate bone (Ilium, ischium and pubis)
 Sacrum
 Coccyx
 Joined anteriorly by pubic symphysis
 Posteriorly by sacro-iliac joint
Bony Pelvis
Female Pelvis
Male Pelvis
Pelvis
Greater Pelvis (pelvis major)
 Location of some abdominal viscera (ileum
and sigmoid colon)
 Bounded by abdominal wall anteriorly, the
iliac fossa posteriolaterally and L5 S1
vertebrae posteriorly
 AKA False Pelvis
Lesser Pelvis ( pelvis minor)
 Location of pelvic viscera – the urinary
bladder and reproductive organs such as the
uterus and ovaries
 Bounded by the pelvic surfaces of the hip
bones, sacrum, and coccyx
 Limited inferiorly by the musculofascial
pelvic diaphragm
 AKA True Pelvis
Pelvic Diaphragm
Pelvic Walls and Floors
 Anterior pelvic wall – is formed primarily
by the bodies and rami of the pubic bones
and the pubic symphysis
 Lateral pelvic walls – formed by the hip
bones and the obturator internus muscles
(O: proximal surface of the ilium and
ischium; obturator membrane I: greater
trochanter of the femur)
Anterior Pelvic Wall
Pelvic Walls and Floor
 Posterior Pelvic Wall – formed by the
sacrum and coccyx, adjacent parts of the
ilia, and the S-I joints; piriformis muscle
covers the area (O: pelvic surface of 2nd and
4th sacral segments, superior margin of the
greater sciatic notch and sacrotuberous
ligament, I: greator trochanter of femur)
Posterior Pelvic Wall
Posterior Pelvic Wall
Pelvic Floor
 Formed by the funnel shaped pelvic
diaphragm – consists of the levator ani and
coccygeus muscles and their fascia
 Stretches between the pubis anteriorly and
the coccyx posteriorly and from one lateral
pelvic wall to the other
Pelvic Floor - Male
Pelvic Floor - Female
Pelvic Floor- Lateral Inferior
Female – Medial View
Levator Ani
 Consists of three parts – the pubococcygeus, the
puborectalis and the iliococcygeus.
 Collectively they run from the body of the pubis,
the tendinous arch of the obturator fascia and the
ischial spine TO the perineal body, the coccyx, the
anococcygeal ligament, the walls of the prostate or
vagina, the rectum and the anal canal
 Innervated by the nerve to levator ani from S4 and
the inferior anal (rectal) nerve (from S2-S4) and
the coccygeal plexus
 Help to support the pelvic viscera; acting together
they raise the pelvic floor and assist the abdominal
muscles in forced expiration activities
Coccygeus Muscle
 O: ischial spine, I: inferior end of the
sacrum, I: branches of S4 and S5
 Forms a small part of the pelvic diaphragm
that supports the pelvic viscera, flexes the
coccyx
Viscera
 Urinary organs in the pelvis
 Ureters – muscular (smooth) tubes running
from kidneys to bladder 25 to 30 cm long
 Bladder – a hollow container surrounded by
a strong smooth muscular wall
 Temporary reservoir for urine
 Apex, Body, Fundus, Neck, Uvula
Ureters
Bladder
Bladder
Bladder
Pelvic Viscera - Female
M v. F Bladder
Viscera
 Bladder Continued
 Detrussor muscle – smooth muscles
surrounds bladder
 Internal sphincter muscle
 Innervation – Parasympathetic to detrussor
(S2-S4)); Sympathetic to internal sphincter
(T12-L1/L2)
Viscera
 Ureter
 Urinary urethral orifice in bladder to
external urethral orifice
 External sphincter – somatic nerves from
S2-S4)
 Prostate
Female Urethra
Female Urethra
Male Urethra
Male Urethra
Uterus
Rectum
 Alimentary canal (GI Tract) connects
sigmoid colon with anus
 Follows the curve of the sacrum and coccyx
 Innervated by sympathetic (T12/L1)and
parasympathetic nerves (S2-S4)
Rectum
Rectum and Anal Canal
Perineum
 Lies inferior to the pelvic outlet and is
separated from the pelvic cavity by the
pelvic diaphragm (Levator ani and
coccygeus muscles)
 Bounded by Pubic symphysis anteriorly;
inferior pubic rami and ischial rami
anterolaterally; ischial tuberosity laterally;
sacrotuberous ligament posterolaterally;
inferiorly by sacrum and coccyx
Perineum
 Two Triangles
– 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
Perineal Membrane
Perineal Body
Perineum-Female
Perineum - Male
Perineum
 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
Muscles – Male
Muscles - Male
Perineum
 Muscles
 External anal sphincter (skeletal muscle) –
O: skin an fascia surrounding anus and
coccyx, I: perineal body, A: closes anal
canal, N: Inferior Anal Nerve (Somatic
nerve from S2-S4) – inhibits voiding
 Internal Anal Sphincter – smooth muscle
innervated by sympathetic NS (S2,S3,S4) –
inhibits voiding
External/Internal Anal Sphincter
Superficial Transverse Perineal
 O: Ischial tuberosity
 I: Perineal body
 A: Support perineal body
 N: Pudenal nerve
External Urethral Sphincter
 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
 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 Female
Superficial Perineum Male
Superficial Perineum Male
Peritoneum
 Continuous with peritoneum of abdomen
 Drapes over pelvic viscera in the midline to
form:
 Pouches
 Folds between viscera and pelvic walls
 Pouches protect viscera from rectum
Female Peritoneum
Female Peritoneum
Male Peritoneum
Male Peritoneum
Major Blood Supply