Pelvic floor. Perineum. Retroperitoneal space.

Pelvic floor. Perineum.

Retroperitoneal space.

Petr Valasek & Miloš Grim pvala@lf1.cuni.cz

Anatomický ústav 1. lékařské fakulty, Univerzita Karlova v Praze

2021-2022

Lacuna vasorum, lac. musculorum, canalis obturatorius

Suprapiriform foramen infrapiriform foramen

Pánevní dno Pelvic floor

1. Pelvic diaphragm

2. Urogenital diaphragm

3. Perineal muscles

Pelvic floor

1. Pelvic diaphragm

levator ani (pubovaginalis/puborectalis) + coccygeus

(2. Urogenital diaphragm)

(superficial + deep transverse perineal)

3. Perineal muscles external anal sphincter

external urethral sphincter

+ urethrovaginal sphincter + urethral compressor

ischiocavernosus bulbospongiosus

arcus tendineus m. l.a.

pelvic fascia

centrum tendineum perinei

Innervation

sacral branches

pudendal nerve (Alcock)

Onuf nucleus in S2 a S3

1. Diaphragma pelvis

Pelvic diaphragm

Pelvic diaphragm

arcus tendineus m. l.a.

pelvic fascia

centrum tendineum perinei

striated muscles from tail somites/spine thus innervated from sacral plexus

Pelvic diaphragm hiatus urogenitalis

hiatus analis

arcus tendineus m. l.a.

centrum tendineum perinei lig. anococcygeum

m. pubovisceralis

m. pubococcygeus m. iliococcygeus

m. (ischio)coccygeus

Pelvic diaphragm

M. levator ani

pars pubica – m. pubovisceralis

m. pubovaginalis m. puboprostaticus m. puboperinealis m. puborectalis – m. pubococcygeus

pars iliaca – m. iliococcygeus

M. coccygeus

pars ischiadica – m. (ischio)coccygeus

Diaphragma pelvis, view from perineum

M. levator ani (1,2,3) a m. cocygeus (4)

3 – m. puborectalis

1 – m. pubococygeus 2 – m. iliococcygeus 4 – m. coccygeus

5 – m. obturatorius int.

Pelvic diaphragm piriform muscle

Levator ani

Levator ani, tendinous arch of levator ani

Sling of the pubovaginalis muscle

Magnetic resonance image of female pelvis in sagittal plane

2008 Endopelvic Fascia in Women: Shape and Relation to Parietal P... : Obstetrics & Gynecology (lww.com)

excavatio vesicouterina excavatio rectouterina, septum vesicovaginale septum rectovaginale

2. Diaphragma urogenitale

Urogenital diaphragm

Diaphragma urogenitale

Closes hiatus urogenitalis – urethra (and vagina) pass through it.

It is connected with pelvic diaphragm in the centrum perinei.

On its surface lie erectile organs and glands.

muscles:

M. transversus perinei profundus (male only) M. sphincter urethrovaginalis (female only) M. compressor urethrae (female only)

M. transversus perinei superficialis (variable)

Fibrous structures:

Membrana perinei

Lig. transversum perinei (male only)

Centrum perinei (corpus perineale/perineal body)

3. Mm. perinei

Perineal muscles

Perineum, hráz, in narrow (obstetric) understanding:

transverse band of soft tissues between the anal orifice and posterior rim of (commissura labiorum posterior)

Broader (anatomical) term perineum (regio

perinealis) designates whole area of pelvic outlet and is divided into anterior regio urogenitalis,

and posterior regio analis. Deep boundary of

perineum is the inferior surface of diaphragma

pelvis and thus fossa ischioanalis is part of it.

Perineal muscles of female, blood supply, innervation

Perineal region, regio perinealis - Urogenital triangle, regio urogenitalis - Anal triangle, regio analis, - Ischio-anal

fossa, fossa ischioanalis (ischiorectalis) Perineum

Perineal region - blood supply, innervation n. pudendus a a. pudenda interna

Mm. perinei, svaly hráze

mm. regionis analis

mm. regionis urogenitalis

+ compressor urethrae

m. ischiocavernosus m. bulbospongiosus

Fibrous structures:

Perineal body (centrum tendineum) Anococcygeal lig.

Fossa ischioanalis

Corpus adiposum fossae ischioanalis Canalis pudendalis (Alcockův kanál)

M. sphincter ani externus (yellow)

M. sphincter ani externus

pars subcutanea – just under skin around anus, split by connective tissue radiating into nearby skin pars superficialis – lies above the subcutaneous part, 0,5 - 1,5 cm thick and 1,5 cm high – strongest part of the sphincter

pars profunda – forms a ring at the level of m.

puborectalis and together they make m.

compressor recti, the most important part of continentia alvi

Function: permanent contraction – relaxes only during defecation

Innervation: n. pudendus

Female external genitalia and perineal muscles - Bulbospongiosus, Ischocavernosus, Compressor of urethra, Urethrovaginal sphincter, Superficial transverse perineal muscle

m. levator ani, m. sphincter ani externus, centrum perinei

Vagina (kolpos) levator ani, superficial transverse perineal muscle bulbospongiosus muscle, ischiocavernosus muscle,

sphincters, levator ani (pubovaginal)

Ischioanal fossa, middle part, Alcock’s canal

Ischioanal fossa

M. sphincter urethrae externus

lies in and above the level of diaphragma urogenitale,

around the urethra, it contains slow muscle fibres for long- term contraction – tone

caudal fibres pass onto sides of vagina, cranial to the apex of prostate

Innervation via pudendal nerve from motoneurons of Onuf nucleus in S2 a S3

M. sphincter urethrovaginalis, M. compressor urethrae

Zijta M et al. Clin Anat 26:110–114 (2013)

Axial T2-weighted image of a 26-year-old nullipara.

C demonstrates the multidirectional organization of the

complex pelvic floor anatomy.

The per-voxel vector values are color coded as follows:

green (anteroposterior direction), blue (craniocaudaldirection),

and red (mediolateral direction).

3b. Mm. perinei Perineal muscles

DEVELOPMENT

DSCN3423.JPG

kuře

Gallus gallus domesticus

křepelka

Coturnix coturnix japonica

Segmental origin of muscles

quail chick

ED3

ED10

Svaly DK

Příklad: somit 32

Molecular analysis of chick cloacal musculature development

Phase 1 – migration do leg - „In“

Pax3

MyoD

ED3.5

ED 5

ED 5 ED 6 ED 7

ED 8 ED 9

Phase 2 – extension from leg - „Out“

MyoD

26

32

The base of a leg gives off muscle cells for cloaca

GFP chick kuře

ED 4 wing ED10

Mouse cloacal-perineal muscles

1. Also murine cloacal muscles develop from flexors

11.5 13.0

12.5

14.5

13.5

LA SAE

Valasek et al., Development 2005

MyoD

wt

cMet -/-

in cMet-/-

2. cMet -/- confirms migratory mechanism

MyHC

Pudendal nerve and its unusual course…

Pelvic floor

&

BIRTH

Female pelvic types:

A. Gynecoid (40%) typical, smooth anterior and posterior segment.

B. Android (30%) narrow anterior segment - wedged aditus pelvis.

C. Anthropoid (20%) aditus pelvis anteroposterior oval.

D. Platypeloid (výskyt 3%) aditus pelvis transverse oval.

26cm

29cm

31cm

Comparative anatomy on 3-D MRI of the urogenital sinus and the periurethral area before and during the second stage of labor during childbirth Apr 2018

The levator hiatus in axial plane with minimally distensible (left) and highly distensible puborectalis muscle (middle) compared to the

dimensions of fetal head at the term (right).

The ultrasound data sets of 227 nulliparous women examined at 36–38 week’s gestation were investigated. Minimal hiatal diameters were measured at rest, on Valsalva and pelvic floor muscle contraction. Results: some women will have to distend only 25%, others by 245%.

Since childbirth-related trauma to the levator ani is common and clinically important, one should consider potential preventative measures. One approach would be to avoid vaginal delivery by performing elective

Caesarean Section. (Švabik et al. 2009)

Normal condition Avulsion after childbirth MRI picture of levator ani muscle

Perineal region - blood supply, innervation n. pudendus a a. pudenda interna

n. ilioinguinalis

n. pudendus

https://www.sciencedirect.com/science/article/pii/S2256208717300317

Regional anesthesia guided by ultrasound in the pudendal nerve territory 2017

Plexus hypogastricus inferior, parasympathetic fibres from sacral nerves

Retroperitoneal space

Diaphragm Pelvis Peritoneum

Backbone, ribs, muscles

Retroperitoneal space

Vena cava inferior, aorta abdominalis, a. mesenterica inferior

Portal circulation vs. inferior v. cava

Nerves of retroperitoneal and subperitoneal spaces

Lumbar and sacral plexuses,

Abdominal and pelvic plexuses and ganglia of autonomic system

Retroperitoneal space, topography of its organs and main vessels

Internal iliac artery, blood vessels of the pelvis

Lymph nodes and ducts on posterior abdominal wall and pelvis

Nodi lymphatici pelvici

Pelvic arteries

AORTA AIC dx

AIC sin

Vena iliaca interna

Sources of illustrations:

Gray´s Anatomy,

Sobottův atlas anatomie člověka, Grada, 2007 Grim, Druga: Základy anatomie, 5. díl

Benninghoff, Drenckhahn: Anatomie I., II.

Carlson,B.M.: Human Embryology and Developmental Anatomy, archiv autora

Literature:

Čihák R: Anatomie 2, Grada 2002, (3. vydání březen 2013) Grim, M., Druga, R.et al: 5. Anatomie krajin těla. Praha,

Karolinum, Galén, 2010; 3. Trávicí, dýchací, močopohlavní a endokrinní systém, Praha, Karolinum, Galén, 2005,

Lüllmann-Rauch R.: Histologie, překlad 3. vydání , Grada 2012 Sadler T. W: Langmanova lékařská embryologie, překlad 10.

vydání , Grada 2011,

Junqueira´s Basic Histology 12th Edition, 2010