Pubic Symphysis
Secondary cartilagenous joint
Articular surface of medial aspect of body of pubis
Covered with hyaline articular cartilage
Disc of fibro-cartilage in between
A cavity may develop in the disc but it is not lined with synovial membrane
There is normally very little movement at the pubic symphysis, except during the latter months of pregnancy
Sacroiliac Joint
Modified synovial plane joint
Articular surfaces are rough
The capsule is attached just beyond the articular margin
The interosseous sacroiliac ligament is one of the strongest ligaments in the body and is posterior to the joint
This articulation is almost immobile, except during pregnancy
• Sacrotuberous ligaments
• Sacrospinous ligaments
• Iliolumbar ligaments
• Posterior superior iliac spine is middle of the joint posteriorly at the level S2
• S2 is end of dura, arachnoid mater and subarachnoid space
• During gait, the amount of accessory movement at the sacroiliac joint helps to protect the lumbar intervertebral discs
Sacroiliac Joint Accessory Ligaments
Abnormalities of Pelvis
• Spina bifida occulta
• Unilateral lumbarisation
• Unilateral sacralisation
• Stress fractures of the sacrum, pubic arch and neck of femur may be first signs of osteoporosis
Walls of Pelvis
• Sacrum and coccyx posterior
• Os coxae below pelvic brim
• Piriformis covers middle three pieces of sacrum
• Passes out of the pelvis through the greater sciatic foramen
• Muscles
• Obturator internus muscle
• Origin of levator ani
• CoccygeusSmout et al., 1969
Obturator nerve
Obturator artery and vein
Parietal peritoneum supplied by the obturator nerve
Pain may be referred to hip or knee joints
Common iliac divides into external and internal iliac
Internal divides into anterior and posterior division branches
Smout et al., 1969
Lateral Walls of Pelvis
Pelvic Fascia
Pelvic fascia can be divided into three:
1. Pelvic wall
Pelvic fascia is a strong membrane over the piriformis and obturator internus
Fuses with the periosteum at their margins
2. Pelvic floor
Fascia is covered with loose areolar tissue
Loose areolar fat tissue lies in the extraperitoneal space between peritoneum and the viscera forming a dead space
Pelvic Fascia
3. Pelvic viscera • Fascia of pelvic viscera is loose or
dense depending on dispensability of organ
Smout et al., 1969
Pelvic Ligaments
Condensation around vessels form ligaments in the pelvis
Cardinal ligament condensation of fascia around uterine artery
Lateral ligament of the rectum is a condensation of fascia around the middle rectal vessels and branches of the hypogastric plexus
Waldyer’s fascia suspends the lower part of the ampulla of the rectum to the hollow of sacrum
Contains the superior rectal vessels and lymphaticsSmout et al., 1969
Pelvic Floor
Urogenital diaphragm
Perineal membrane and the superficial transverse perineii
The pelvic floor is a dome-shaped striated muscular sheet
The levator ani is made up mainly of the pubococcygeus, the puborectalis and the iliococcygeus
It encloses the bladder, uterus and rectum
Together with the anal sphincters, has an important role in regulating storage and evacuation of urine and stool
Stoker, 2009
Deep Perineal Pouch: Urogenital Diaphragm
Superior is the areolar tissue on the under surface of the levator ani
• The sphincter urethrae around urethra and transverse perineii in the deep pouch
• Perineal membrane fills in pubic arch below the muscles
• Muscles are supplied by perineal branch of pudendal nerve
• In lateral portion of the deep pouch, run dorsal nerve of clitoris and internal pudendal artery and vena commitans
superficial pouch
deep pouch
sphincter
urethrae
perineal
membrane
Levator Ani
• Arises, anteriorly, from the posterior surface of the body of pubis lateral to the symphysis
• Posterior from the inner surface of the spine of the ischium
• Between these two points, from a tendinous arch called the white line (arcus tendineus) adherent to the obturator fascia
Last,1984
Unites with the opposite side to form most of the floor of the pelvic cavity
The fibres pass downward and backward to the middle line of the floor of the pelvis
Inserted from before backwards, into perineal body
Side of the rectum and anal canal
Anococcygeal raphe
The side of the last two segments of the coccyxLast 1984
Levator Ani
The anterior fibres, pubovaginalis, pass behind the vagina, unites with the opposite side
Inserted into the perineal body, the central point of the perineum
Joining the fibres of the sphincter ani externus and transversus perineii
Last 1984
Levator Ani
Levator Ani
• The puborectalis forms a U-shaped sling, holding the anorectal anteriorly, blending with the deep fibres of the external anal sphincter
• Anococcygeal raphe lies between the coccyx and the margin of the anus
• Nerve supply, inferior rectal nerve and perineal branch fourth sacral
Last 1984
Levator Ani
In women, the levator muscles or their nerve supply, can be damaged in pregnancy or childbirth
There is some evidence that these muscles may also be damaged during a hysterectomy
Pelvic surgery using the "perineal approach" (between the anus and coccyx) is an established cause of damage to the pelvic floor. This surgery includes coccygectomy
Empty Female Bladder
• Bladder has a apex, triangular superior surface, base and two inferolateral surfaces, neck inferiorly
• Posterior or base is fixed, the two ureters enter obliquely at the junction of the superior surfaces and base
• The internal urethral orifice or neck is at the junction of the base and two inferolateral surfaces
• The interior of the bladder is lined with transitional epithelium which is thrown into folds in the empty bladder, except for the smooth triangular area of base called trigone
• Pubo vesical ligaments connect the neck to the pubic bone
• Base is attached to the supravaginal portion of the cervix and anterior fornix of vagina
• Peritoneum only covers superior surface
• Blood supply, superior and inferior vesical arteries
• Venous plexus into internal iliac vein
Female Bladder
Control of Micturition
• Smooth or detrusor muscle at the neck is the internal sphincter, supplied by the sympathetic
• Parasympathetic contracts detrusor muscle and relaxes internal sphincter
• Sphincter urethra or external sphincter is striated muscle
• Supplied by perineal branch of pudendal nerve S2,3,4,
Structure of Female Urethra
• Urethra 3-5 cm long
• Enters deep pouch where it is surrounded by
• Sphincter urethra, also called external sphincter of bladder
• Urethra pierces perineal membrane
• No fascia between lower two thirds of urethra and vagina
• Opens into vestibule, between clitoris and vagina
• Muscular layer continuous with bladder
• Spongy erectile tissue
• Plexus of veins
• Mucous membrane transitional
• Distal non keratinising stratified squamous
• Para urethral glands and ducts open into urethra, homologues of prostatic glands
Smout et al 1969
Urethra
Urethra
Urethra is supported by the fascia of the pelvic floor including pubo-vesical and pubocervical ligaments
If this support is insufficient, the urethra can move downwards
In times of increased abdominal pressure resulting in stress urinary incontinence (SUI)
The physical changes that can occur during pregnancy, delivery and menopause can predispose to SUI
Nuggaard and Heit in Bayliss 2010
Normal uterus is anteverted
i.e. anterior to vertical plane going through the vagina
Posterior fornix deeper
Anteflexed
Bent anteriorly junction of body and cervix
Pear-shaped muscular organ
8 cm long; 5 cm width; 3 cm thick
Non-pregnant state
Pelvic organ
Uterus
• Fundus
• Body
• Cervix opens into vault or fornices of vagina
• Fundus is the portion above entrance of uterine tubes
• Covered with peritoneum
• Body
• Triangular cavity
Uterus
• Isthmus is a circular borderline area between the body and cervix
• Isthmus is the supra vaginal portion of cervix, the lower uterine segment
• Intravaginal is surrounded by gutter by fornices of vagina,
• Posterior is deeper covered with peritoneum
• Internal os is the opening from the cavity of body
• Spindle shaped cavity cervix
• External os is the opening into vagina
Cervix
• Cervical canal is lined by columnar epithelium
• External os
• Junction of columnar of the cervical canal
• Stratified epithelium of the intravaginal portion
• Site of cancer of cervix
• Cervical smear
• At birth cervix is larger than the body
• Fully developed
• Cervix is one third of body
Cervix
Supports of Uterus
• Upper
• Round ligament
• Broad ligament anteverted
• Transverse ligament
• Pubocervical
• Uterosacral
• Lower
• Levator ani, coccygeus
• Perineal body
Round Ligament
• Round ligament and ligament of ovary
• Develop from the gubernaculum
• Side of uterus, junction fundus and body
• Inguinal canal to labium majus
• Ante version
Pubocervical Ligament
Attached
Anteriorly to posterior aspect of body of body of pubis
Passes to neck of bladder
Anterior fornix of vagina
Pubocervical ligaments help to
Maintain normal angle of 45° between the vagina and horizontal
Decrease may cause a cystocoele
Transverse Ligament
Transverse or cardinal or Mackenrodt’s ligament
Thickening of visceral layer of pelvic fascia around uterine artery
Lateral to medial in base of broad ligament
Uterosacral Ligament
Uterosacral contains fibrous tissue
Non-striated muscle
Attached from the cervix to the middle of sacrum
Contains lymphatics draining cervix to sacral glands
Uterosacral help to keep uterus anteverted
If uterus is anteverted it cannot prolapse
Blood Supply
• Uterine from internal iliac
• Ovarian from aorta at L2
• Vaginal arteries from internal iliac
• Anterior and posterior arcuate run in middle layer
Serous layer
Myometrium
No submucous layer
Endometrium
Compact at surface of uterine cavity and spongy layer are supplied by spiral arteries
Basal layer is not shed during menstruation; supplied by radial branches
Veins below artery
Plexus in lower edge broad ligament into internal iliac
Blood Supply
Embolization of Fibroids
• Fibroids vary in size and position in uterine wall
• May enlarge and compress ureters or other structures in pelvis
• A small catheter is inserted in the groin, into the femoral artery
• Small particles are introduced through the catheter into the uterine artery
• They block the blood supply to the fibroids
• The fibroids thus starved of blood shrivel and die over the next few months
Nerve Supply of Uterus
• Pain from cervix via parasympathetic S2,3
• Pain from body via sympathetic to T11 and T12
Broad Ligament
• Fold of peritoneum from side of uterus to side wall of pelvis
• Framework of pelvic fascia
• Parametric fat
• Anterior surface looks inferiorly
• Free upper border
• Base lies on pelvic floor
• Uterine tubes
• Ovarian vessels
• Uterine vessels
• Epoophoron
• Paroophoron
• Round ligament of uterus and ligament of ovary
• Transverse ligament
• Ovary attached to posterior layer
• Ureter in base below uterine artery
Contents of Broad Ligament
Uterine tube lies in medial four fifths of free border of broad ligament
Lateral one fifth
Contains ovarian vessels
Infundibulo-pelvic or suspensory ligament of ovary
Epoophoron
Parallel tubules remains of mesonephric tubules
Gartner's duct remains of mesonephric duct, may form cysts
Broad Ligament
Uterine Tube
• Intramural
• Isthmus
• Ampulla
• Infundibulum surrounded by fimbria
• Lined ciliated columnar epithelium
• Beats towards uterus
Peritoneum loosely attached to ampulla
• Tightly to isthmus, if ectopic implanted here, ruptures earlier
• Fimbria surrounding opening into peritoneal cavity
• Ovarian fimbria is longest
Ovary
• Attached to posterior layer of broad ligament meso ovarian
• Covered with germinal epithelium
• Related to side wall of pelvis which is covered with peritoneum
• Obturator internus muscle
• Obturator nerve supplies the parietal peritoneum
• Posterior to ovary is the ureter
• Ligament of ovary medially
• Obturator nerve supplies the parietal peritoneum
• Irritation of the peritoneum of the side wall by bleeding at ovulation or by lesions involving the ovary
• May result in referred pain to medial side of the thigh or the knee
Ovary
Blood supply
One ovarian artery from lateral aspects of aorta L2
Right vein drains into inferior vena cava
Left drains into left renal vein
Lymphatics into para aortic glands L2
Ovary
Vagina
Fornices, gutters which surround the cervix
Normal anteverted antiflexed
Anterior fornix is shallow anterior wall is shorter than posterior
Posterior deeper, covered with peritoneum of the pouch of Douglas
Most dependent part of peritoneal cavity
Walls in contact except superior
Opens into vestibule of vagina
Uterine Artery
• Uterine artery lies superior to the ureter at lateral fornix of vagina
• Base of broad ligament
• Erectile tissue
• Muscular wall
• Pelvic fascia
• Nonkeratinised stratified squamous epithelium
• Urethra lower third anterior wall
• No fascia between lower two thirds of urethra and vagina
• Upper portion of the vagina is clasped by the pubo-vaginalis portion of the levator ani
Vagina
Deep pouch
Sphincter urethrae, deep transverse perineii, pierces perineal membrane, opens into vestibule of vagina
Hymen fold of mucous membrane at external opening
Lateral are the bulbs of vestibule
Covered by bulbospongiosus muscle
Greater vestibular (Bartholin's) glands lie behind the bulbs of vestibule
Ducts open into orifice of the vagina
Posterior to vagina is the perineal body
deep pouch
superficial
Vagina
Peritoneum on Uterus and Vagina
• Reflected from the superior surface of the bladder
• Junction of the supravaginal portion of the cervix and the body of the uterus forming the utero vesical pouch
• Peritoneum then covers body, fundus and posterior surface body and then the supravaginal cervix and posterior fornix of vagina
• Peritoneum then reflected on to junction of upper two thirds and lower third of rectum forming
• Pouch of Douglas is most dependent part of female peritoneal cavity
Blood and Nerve Supply Vagina
• Uterine artery
• Vaginal
• Internal pudendal
• Labial
• Ilio Inguinal nerve supplies the anterior wall
• Labial nerves supply the posterior wall
Lymphatics of Vagina
• Internal iliac
• Lower third
• Medial group of proximal superficial inguinal glands
Pelvic Plexus
• Lumbar splanchnics L1-L2
• Presacral nerve
• Anterior to body of L5
• Divide into pelvic plexuses
• Postganglionic of sympathetic that relayed in lumbar and sacral ganglia causes contraction of sphincters of bladder and anal canal
Pelvic Parasympathetic
• Preganglionic have cell bodies in lateral column of segments S2,3,4
• Ganglia found close to or in wall of organ
• Supplies intestine from splenic flexure to upper two thirds of anal canal, bladder
• Motor to walls and inhibitory to sphincters
• Parasympathetic causes erection
Rectum
• Rectum is a continuation of pelvic colon
• Starts at the third piece of the sacrum
• Ends 5 cm from the tip of coccyx
• Lower end is dilated at the ampulla, at the anorectal junction
• There are no taeniae and no appendices epiplociae on the rectum
It has an antero-posterior curve, above it is angled anteriorly by the puborectalis
Below convex forwards
Three lateral curves
Two concave to left, one to right, where the valves of Houston, which consist of circular muscle and mucous membrane
Peritoneum covers upper third on front and sides
Middle third on front, none on lower third
Rectum
Blood Supply of Rectum Superior rectal, continuation of inferior
mesenteric artery
Runs in Waldyer’s fascia from hollow of sacrum to the lower part of the ampulla of the rectum
Supplies mucous membrane as far mucocutaneous junction of anal canal
Venous drainage into portal system
Middle rectal the muscle layer
Small twigs from median sacral
Anal Canal
• Starts at anorectal junction
• Below ampulla of rectum
• Passes backwards
• Approx 4 cm
• Ends at anus
• Anterior: perineal body
• Posterior: anococcygeal body
• Lateral: ischiorectal fossae
Muscles of Anal Canal
The anal sphincter is a multilayered cylindrical structure
The inner smooth muscle of the internal sphincter
Surrounds upper two thirds
Lower two thirds the outer striated muscle layer of the external sphincter
Anorectal ring formed by puborectalis and the deep part of the external sphincter
Peri Anal Fascia
Perianal fascia continuation of longitudinal coat of rectum
Medial to deep and superficial external sphincters
Attached at Hilton’s line
Passes to lateral wall
Above subcutaneous sphincter
Lateral sheet passes between soft ischiorectal fat and subcutaneous fat to lateral wall
Splits to form pudendal canal and is
Continuous superiorly with the lunate fascia, which passes above soft ischiorectal fat
It is medial to deep and superficial sphincter
Above subcutaneous sphincter
Anal Canal
Puborectalis portion levator ani holds the anorectal junction anteriorly
Deep and subcutaneous parts of external are true sphincters
No bony attachments
Superficial attached to coccyx and the perineal body
Muscles of Anal Canal
Anorectal ring
Internal sphincter
Puborectalis
Puborectal fascia
External sphincter
Deep, true sphincter, no bony attachments
Inferior rectal nerve S3,4
Superficial S4
Subcutaneous, true sphincter
Inferior rectal nerve S3,4
Muscles of Anal Canal
Upper two thirds lined by
columnar epithelium
Lower third by skin
Junction of two is Hilton’s white line skin
Anal columns contain radicles of superior rectal artery and veins 4,7,11
At the lower end joining the columns are mucosal folds called anal valves
Anal sinuses lie behind
Skin supplied by inferior rectal vessels and nerves
Anal Canal
Blood and Nerve Supply
• Upper two thirds
• Columnar epithelium
• Superior rectal artery
• Autonomic nerves
• Derived from cloacae
• Lower third
• Skin
• Inferior rectal S3,4,
• Somatic nerves
• Derived from proctodeum
Venous Drainage
Mucosa upper two thirds
Superior rectal vein
Portal system
Lower third
Inferior rectal vein
Vein into systemic system
Portal systemic anastomosis’ 4,7,11
Lymphatic Drainage
Upper third
Pre aortic inferior mesenteric
Waldeyer’s fascia passes from sacrum to the ampulla of rectum
Encloses superior rectal vessels and lymphatics
Internal iliac
Lower Third
Inferior rectal cross ischio-rectal fossa
Medial superficial inguinal glands
Anal Sphincters
• The internal and external anal sphincters are primarily responsible for maintaining faecal continence at rest and when continence is threatened, respectively.
• Defecation is a somato-visceral reflex regulated by dual nerve supply (i.e. somatic and autonomic) to the anorectum.
Bharucha 2006
Anal Sphincters
• The net effects of sympathetic and cholinergic stimulation are to increase and reduce anal resting pressure, respectively.
• Faecal incontinence and functional defecatory disorders may result from structural changes and/or functional disturbances in the mechanisms of faecal continence and defecation.
Bharucha 2006
Ischiorectal Fossa
Ischiorectal fossa contents
Soft ischiorectal fat
Lunate fascia above the fat
Inferior rectal vessels pass above the fat to reach medial wall
Perineal branch of S4
ischiorectal fossa
Ischiorectal fossa contents
lunate fascia above the soft ischiorectal fat
Inferior rectal vessels and nerve pass above lunate fascia and the fat to reach medial wall
Subcutaneous fat lies below perianal fascia
Perineal branch of S4
Lymphatics cross fossa
Ischiorectal Fossa
Pudendal Canal
• Runs posterior to anterior
• Pudendal canal contents
• Pudendal nerve
• Inferior rectal nerve
• Dorsal nerve of clitoris
• Perineal nerve
• Labial nerves
• Internal pudendal vessels
Pudendal Block
Pudendal nerve
Lies on the sacrospinous ligament
Anaesthetizes posterior wall of the vagina
Ilioinguinal nerve supplies the anterior wall
Age, pregnancy, family history, and hormonal status all contribute to the development of pelvic organ prolapse. The vagina is suspended by attachments to the perineum, pelvic side wall and sacrum via attachments that include collagen, elastin, and smooth muscle. Surgery can be performed to repair pelvic floor muscles. The pelvic floor muscles can be strengthened with Kegel exercises.
Disorders of the posterior pelvic floor include rectal prolapse, rectocele, perineal hernia, and a number of functional disorders including anismus. Constipation due to any of these disorders is called "functional constipation" and is identifiable by clinical diagnostic criteria.