Maternal Anatomy

AILEEN JAE C. CABORNAY, MD

FIRST YEAR RESIDENT IN TRAINING

DIANE ROSE SANTIAGO-CAJIPE. MD, FPOGS

MODERATOR
I. ANTERIOR ABDOMINAL
WALL
II. EXTERNAL GENERATIVE
ORGANS
III. INTERNAL GENERATIVE
ORGANS
 I. ANTERIOR
ABDOMINAL WALL
SKIN

LANGER LINES
Subcutaneous Layer
Camper’s fascia Scarpa’s fascia
› Superficial › Deeper
› predominantly fatty layer › membranous layer

PERINEUM

› MONS PUBIS › COLLE’S FASCIA

› LABIA MAJORA
› ISHIOANAL FOSSA FAT
External oblique
Rectus Abdominus

Transversus abdominis
internal oblique

Pyramidalis
Rectus Sheath
 fibrousaponeuroses of the external oblique, internal
oblique, and transversus abdominis muscles join in
the midline

 Arcuate line
 Cephalad- aponeuroses invest the rectus abdominis
bellies above and below
 Caudal- all aponeuroses lie anterior to the rectus
abdominis muscle, and only the thin transversalis
fascia and peritoneum lie beneath.
Blood Supply
A. Femoral Artery Branches B. External Iliac Artery Branches
› superficial epigastric › inferior "deep" epigastric vessels
› superficial circumflex iliac › deep circumflex iliac vessels-.
› external pudendal
Superficial
epigastric a.
Superfiial
circumflex a.
External pudendal a.

skin Femoral artery

subcutaneous layers
of the AAW and mons pubis
 Blood Supply
deep circumflex a.
B. External Iliac Artery Branches
› inferior "deep" epigastric vessels
› deep circumflex iliac vessels-.
inferior External Iliac Artery
epigastric a.

muscles
and fascia
of the AAW
Hesselbach triangle
Bounderies
 Inferiorly: inguinal
ligament
 Medially: lateral border
of the rectus muscles
 Laterally: inferior
epigastric vessels.
Innervation
 Intercostal nerves (T7-11)
 Subcostal nerve (T12)
 Iliohypogastric nerve-
skin over suprapubic area
 Ilioinguinal nerves (L1)-
› skin of the lower abdominal wall
› upper portion of the labia majora
› medial portion of the thigh
 T10 dermatome- - approximates the level of the umbilicus. Labor qnd
vaginal birth
 T 4 dermatome- regional cesarean delivery and sterilization
Innervation
 Intercostal nerves (T7-11)
 Subcostal nerve (T12)
 Iliohypogastric nerve-
skin over suprapubic area
 Ilioinguinal nerves (L1)-
› skin of the lower abdominal wall
› upper portion of the labia majora
› medial portion of the thigh
 T 4 dermatome
 T10 dermatome- approximates the level of the umbilicus.
III. EXTERNAL GENERATIVE
ORGANS
PUDENDA or VULVA
 includes all structures visible externally from
the pubis to the perineum:
 Mons pubis
 Labia majora and minora
 Clitoris
 Hymen
 Vestibule
 Urethral opening
MONS PUBIS
 fat-filled cushion that lies over the symphysis
pubis
 At puberty, covered by curly hair that forms
the escutcheon
LABIA MAJORA
 Male homologue: scrotum
Length:
 continuous directly with the mons pubis
7-8 cm
 It is where the round ligaments terminate
Depth:  Outer surface with hair while inner surface
2-3 cm without hairs
 In children and nulliparous women - close apposition
Thickness  In multiparous women - gapes widely

1-1.5 cm  Merge posteriorly to form the posterior

commissure.
LABIA MINORA
 composed of connective tissue with many
length vessels and some smooth muscular fibers
s 2-  moist and reddish, similar in appearance to a
10 c mucous membrane

widths  2 lamellae superiorly

1-5 cm  lower pair: forms the frenulum of the clitoris
 upper pair: forms the prepuce
 Inferiorly, it forms the fourchette.
CLITORIS
 Male homologue: penis
 composed of a glans, a corpus, and two crura
 rarely exceeds 2 cm in length.
 covered by stratified squamous epithelium that
is richly supplied with nerve ending
 principal female erogenous organ
VESTIBULE
- almond-shaped
 BOUNDARIES:
 Lateral- Hart line
 Medial – external surface of hymen
 Anteriorly- frenulum
 Posteriorly- fourchette

 6 openings:
 urethra

 vagina

 ducts of the Bartholin glands (2)

 ducts of the paraurethral glands/skene glands (2)
 Vestibular Glands
Bartholin glands Paraurethral glands
 greater vestibular glands  Lies in the inferior aspect
 0.5 to 1 cm in diameter of the urethra
 lie inferior to the vestibular  Skene glands - largest
bulbs and deep to the
inferior ends of the  Minor vestibular glands
bulbocavernosus muscle - are shallow glands
 ducts are 1.5 to 2 cm long lined by simple mucin-
and open distal to the secreting epithelium
hymenal ring at and open along Hart
5 &7 o'clock line.
 Vestibular Glands
Bartholin glands Paraurethral glands
 greater vestibular glands  Lies in the inferior aspect
 0.5 to 1 cm in diameter of the urethra
 lie inferior to the vestibular  Skene glands - largest
bulbs and deep to the
inferior ends of the  Minor vestibular glands
bulbocavernosus muscle - are shallow glands
 ducts are 1.5 to 2 cm long lined by simple mucin-
and open distal to the secreting epithelium
hymenal ring at and open along Hart
5 &7 o'clock line.
Vestibular Bulbs
 Male homologue: corpus spongiosum of the
penis
 almond-shaped, mainly composed of
aggregations of veins
 lie beneath the bulbocavernosus muscle on
either side of the vestibule.
 If injured, may rupture to create a vulvar
hematoma.
VAGINAL OPENING AND HYMEN
HYMEN
 elastic and collagenous connective tissue
 Lined by stratified squamous epithelium
 no glandular or muscular elements, and it is
not richly supplied with nerve fibers
 Appearance varies with age:
 Newborn- very vascular and redundant
 Pregnant- thick, rich in glycogen
 Menopause- thin; focal cornification may develop
VAGINAL OPENING AND HYMEN
VAGINAL OPENING AND HYMEN
VAGINA
 Musculo-membranous structure
 Extends from the vulva to the uterus
 interposed
anteriorly and posteriorly between the urinary
bladder and the rectum .
 Lining
epithelium: non-keratinized stratified squamous
epithelium
 no glands
 abundant vascular supply
VAGINA
 usual vaginal length:
 Anterior: 6 to 8 cm
 Posterior: 7 to 10cm
VAGINA
o Divided by a septum from the urethra and the rectum
 Anteriorly- vesicovaginal space
 Posteriorly- rectovaginal space

 upper fourth of the vagina is separated from the

rectum by the rectouterine pouch (cul-de-sac of
Douglas)
 subdivided into the anterior, posterior, and two
lateral fornices by the uterine cervix
VAGINA
BLOOD SUPPLY LYMPHATIC DRAINAGE

cervicovaginal branches
Upper Third iliac nodes
of uterine arteries

Middle third inferior vesical arteries internal iliac nodes

middle rectal and

Lower third internal pudendal inguinal lymph nodes
arteries
PERINEUM
 Boundaries:
 Anterior: Pubic symphysis
 Posterior: Ischiopubic rami
 Anterolateral: Ischial tuberosities
 Posterolateral: Sacrotuberous ligaments
 Posterior: Coccyx

 Blood supply:
 Internal pudendal artery (inferior rectal artery and
posterior labial artery)
 PERINEUM

 ANTERIOR TRIANGLE
 Also called Urogenital Triangle
 Further subdivided into:
 Superficial space – closed compartment
 Deep space – continuous superiorly with the
pelvic cavity

 Boundaries:
 Superior: Pubic rami
 Lateral: Ischial tuberosities
 Posterior: Superficial transverse pernieal muscle
 SUPERFICIAL SPACE OF THE ANTERIOR TRIANGLE
Ischiocavernosus • Helps maintain clitoral erection
• Constrict the vaginal lumen and aid in the release of
Bulbocavernosus secretions of the Bartholin’s gland
• Contributes to clitoral erection
Superficial transverse pernineal
• contributes to the perineal body
muscles

DEEP SPACE OF THE ANTERIOR TRIANGLE

• Branches of the internal pudendal artery
• Compressor urethrae
• Dorsal nerve
• Urethrovaginal sphincter muscles
• Vein of the clitoris
• External urethral sphincter
• Parts of urethra and vagina
 PERINEUM

 POSTERIOR TRIANGLE
 Contains:
 Ischiorectal fossa
 Anal canal
 Anal sphincter complex
 Branches of the internal pudendal vessels
 Pudendal nerve
Pelvic Diaphragm
LevatorAni: pubococcygeus,
puborectalis, ilieococcygeus
Coccygeus muscles:
Anus
Anus
Internal anal sphincter (IAS)
 Provides bulk of resting pressure
 Relaxes for defacation

External anal sphincter (EAS)

 maintains a constant state of resting contraction and
continence
 Extra squeeze, relaxes for defecation
Anal cushion
 Highly vascularized
 Aids in fecal continence
 Engorgement due to increased
uterine size, excessive straining
and hard stools, leads to
hemorrhoids
Pudendal nerve
 Formed by teh anterior rami of S2-S4
 Lies posteromedial to the ischial spines
Pudendal nerve
 3 Terminal branches:
1. Dorsal nerve – supplies the skin of teh clitoris
2. Perineal nerve – serves the muscles of the
anterior triangle and labial skin
3. Inferior rectal branch – supplies the following:
a. external anal sphincter
b. mucous membrane of the anal
c. perianal skin
II. INTERNAL GENERATIVE
ORGANS
 INTERNAL GENERATIVE ORGANS
Cervix

 Anteriorly, upper boundary- internal os

 Supravaginal segment
 is covered by peritoneum on its posterior surface
 attached to the cardinal ligaments anteriorly, and it
is separated from the overlying bladder by loose
connective tissue.
 Lower vaginal portion- portio vaginalis.
Cervix
 The mucosa is a single layer of very high
ciliated columnar epithelium that rests
on a thin basement membrane
 Glandsfurnish the thick, tenacious
cervical secretions.
Uterus  Ligaments:
 Thick- walled, hollow,  Broad Ligaments
muscular organ  Cardinal ligament
 Round ligament
 Blood supply:  Utero sacral ligamant
 uterine artery
 ovarian artery
Body of the Uterus
 composed of serosal,
muscular, and
mucosal layers.
 The serosal layer is
formed by the
peritoneum that
covers the uterus.
BROAD LIGAMENT
 are made up of two winglike structures that extend from the lateral margins of
the uterus to the pelvic walls.
 divide the pelvic cavity into anterior and posterior compartments.
 Mesosalpingx

Mesovarium

Mesoteres
CARDINAL LIGAMENT
 transverse cervical ligament or the Mackenrodt ligament
 densest portion
 composed of connective tissue that medially is united firmly to
the supravaginal portion of the cervix.
ROUND LIGAMENTS
 extend from the lateral portion of the uterus, arising below and
anterior to the origin of the oviducts.
Lymphatics

 Cervix
 terminate mainly in the hypogastric nodes, which
are situated near the bifurcation of the common
iliac vessels.
 body of the uterus
 internal iliac nodes and periaortic lymph nodes
Oviducts
 commonly called the fallopian tubes, vary in length from 8 to 14 cm.
 lumen is lined by mucous membrane.

PARTS
 interstitial portion
 isthmus
 ampulla
 infundibulum or fimbriated extremity- funnel-shaped opening at the distal
 Musculature
 inner circular and outer longitudinal layer.
 Lined by a single layer of columnar cells, some of them ciliated
and others secretory.
 No submucosa
 the epithelium is in close contact with the underlying muscle.
 Tubal peristalsis
Ovaries

 attached to the broad ligament by the

mesovarium.
Ovaries
 utero-ovarian ligament extends from the lateral and
posterior portion of the uterus, just beneath the
tubal insertion, to the uterine pole of the ovary.
 It is covered by peritoneum and is made up of muscle
and connective tissue fibers.
 infundibulopelvic or suspensory ligament of the
ovary- extends from the upper or tubal pole to the
pelvic wall
Ovaries
PARTS:
 Cortex- outer layer
 Medulla- central portion

BLOOD SUPPLY
 The ovaries are supplied with both sympathetic
and parasympathetic nerves.
 IV. LOWER
URINARY TRACT ORGANS
 AA

0varian Artery
Ureter

Common Iliac

Internal iliac
External iliac

Uterosacral ligament

Uterus
Urinary bladder
 External iliac

Uterosacral ligament

Uterus
Cardinal ligament
Urinary bladder
 Crosses over the
bifurcation of the CIA
Medial to the OA
Medial to internal Iliac
 Traverses Anterolateral to
approximately utero sacral
1-2 cm lateral ligaments
to the cervix

Uterine artery
Cardinal ligament
V. PELVIC ANATOMY