1. Xiu Xiu Jiang Ai Xia Liu Telephone (office): Women’s Hospital, School of Medicine, Zhejiang University

2. Anatomy of the Female Reproductive System
Jiang Xiu Xiu
Women’s hospital, School of Medicine, Zhejiang University

3. Outline Bony pelvis Pelvic floor External genitalia Internal genitalia
Vascular, lymphatic and nervous system
Adjacent organs

4. Bony Pelvis
Front view Rear view

5. Pelvis A basin-shaped ring Latin word “basin”
To bear the weight of the upper body when sitting and standing
To contain and protect the pelvic organs
"Pelvis" is the Latin word for a "basin" and the pelvis thus got its name from its shape . Since pelvis is a bone structure, it is very strong and stable. Generally, its function is to bear the weight of the upper body when sitting and standing; to contain and protect the pelvic organs, for example, bladder, uterus and rectum.

8. Pelvis child-bearing and child-birth function in women. Female Male
"Pelvis" is the Latin word for a "basin" and the pelvis thus got its name from its shape .
In women the pelvis is wider and has a larger capacity than in men, a condition that reflects the child-bearing function in women.
Female Male

9. Key factors of bony pelvis
related to child-birth
Size
Shape
Joint (movement )
Ligament (relaxation)

10. Anatomy of the Bony Pelvis
Bones
Joints
Ligaments
Three planes of the pelvis
Types of the female pelvis

12. Bones Sacrum (1#) : 5 fused vertebrae
Coxae : ilium (2#) Ischium (3#) pubis (4#)
Coccyx : 3 fused cartilaginous bones
These three bones fused together to form a whole piece named coxae.

13. Bones sacral promontory Sacrum : 5 fused vertebrae sacral promontory
superiormost portion of the sacrum
border of the pelvic inlet
can be touched
bone marker
Coccyx : 4 fused cartilaginous bones

14. Bones Ischium (3#) Coxae : ilium (2#) pubis (4#) tuberosity
ischial tuberosity
--- marks the lateral boundary of the pelvic outlet.
These three bones fused together to form a whole piece named coxae.

15. Joints Sacro-iliac joint (SI) - minimal motion
Sacro-coccygeal joint (SC)
- slightly moveable (forward and backward).
Symphysis pubis - slightly movable

16. Joints Symphysis pubis Greek word “growing together”
Absorb shock during walking.
Delivery of baby.
gap of the symphysis pubis
non-pregnant: 4-5mm
Pregnant: less than 9mm

17. Joints Diastasis of the symphysis pubis symphysiotomy result from:
rapid birth; forceps delivery; prenatal;
symptom:
pelvic girdle pain
--- involving 45% of all pregnant women and 25% of all women postpartum
prenatal
symphysiotomy

18. Ligaments Sacro-iliac joint Sacro-coccygeal joint
Anterior sacroiliac ligament
Interosseous sacroiliac ligament
Posterior sacroiliac ligament
Sacrotuberous ligament
Sacro-coccygeal joint
anterior sacrococcygeal ligament
posterior sacrococcygeal ligament
lateral sacrococcygeal ligaments
Intercornual sacrococcygeal ligament

19. Ligaments Sacrospinous ligament
Extend from the lateral border of the sacrum and coccyx to the ischial spine
A thin, triangular ligament
With sacrotuberous ligament, Closes off the greater sciatic notch to form the greater sciatic foramen and closes off the lesser sciatic notch to form the lesser sciatic foramen
Its main function is to prevent posterior rotation of the ilium with respect to the sacrum
When pelvic ligaments and connective tissue supports are severally attenuated or absent in women, the sacrospinous ligament provides a consistently strong site for fixation of the vaginal apex, so called sacrospinous ligament suspension, in which the vaginal apex is suspended posteriorly and laterally to the ligament on either side or both sides.[3]

20. Ligaments Sacrospinous ligament sacrospinous ligament suspension
Function
to prevent posterior rotation of the ilium with respect to the sacrum
Fixation site for pelvic organ prolapse
sacrospinous ligament suspension
the vaginal apex is suspended posteriorly and laterally to the ligament on either side or both sides
Its main function is to prevent posterior rotation of the ilium with respect to the sacrum
When pelvic ligaments and connective tissue supports are severally attenuated or absent in women, the sacrospinous ligament provides a consistently strong site for fixation of the vaginal apex, so called sacrospinous ligament suspension, in which the vaginal apex is suspended posteriorly and laterally to the ligament on either side or both sides.[3]

21. Ligaments Sacrotuberous ligament
Extend from the posterior aspect of the lower 3 sacral vertebrae to the ischial tuberosity
It is flat, and triangular in form; narrower in the middle than at the ends.

22. Boundary of pelvis Border line posterior
upper border of sacral promontory
lateral
iliopectineal line
anterior
upper border of pubis

23. Boundary of pelvis False pelvis ( pelvis major )
The female bony pelvis is divided into:
False pelvis ( pelvis major )
---above the border line and has no obstetric importance.
True pelvis ( pelvis minor )
---below the border line and related to the child -birth
The bone delivery canal of childbirth

24. Planes of True Pelvis
inlet
outlet
mid-cavity

25. Planes of True Pelvis pelvic inlet is heart-shape, . posteriorly
bounded by
. posteriorly
upper border of sacral promontory
. laterally:
iliopectineal line
. anteriorly:
upper border of pubis
anteroposterior about 11cm.
transverse about 13cm
oblique about 12.75cm

26. Planes of True Pelvis Mid-cavity
It is a segment, the boundaries of which are:
the roof is the plane of pelvic inlet,
the floor is the plane of the plane of pelvic outlet,
anterior - the shorter symphysis pubis,
posterior - the longer sacrum.
Interspinous diameter = 10 cm
between the tips of ischial spines.

27. Planes of True Pelvis
Pelvic outlet: 2 triangular planes with 1 base which is the intertuberous diameter
Anterior sagittal plane:
apex - the lower border of the symphysis pubis.
laterally: the ischiopubic arch
Posterior sagittal plane:
apex - the tip of the coccyx.
Laterally - sacrotuberous ligament
Two intersecting triangle， It is lozenge-shaped

28. Diameters of pelvic outlet
Planes of True Pelvis
Diameters of pelvic outlet
Antero-posterior diameter =11.5cm
from Sacro-coccygeal joint to the lower border of symphysis pubis.
Transverse diameters (Bituberous diameter) = 9 cm
between the inner aspects of the ischial tuberosities.
Anterior sagittal diameter = 6 cm
from the lower border of the symphysis pubis to the centre of the bituberous diameter.
Posterior sagittal diameter = 8.5 cm
from Sacro-coccygeal joint to the centre of the bituberous diameter.

29. Caldwell- Moloy Classification of Pelvic Types (1933)
Four types of female pelves were described. Actually, the majority of pelvis are mixed types.

30. Gynaecoid pelvis It is the normal female type.
Inlet is slightly transverse oval.
Sacrum is wide with average concavity and inclination.
Side walls are straight with blunt ischial spines.
Sacro-sciatic notch is wide.
Subpubic angle is o.
The gynaecoid pelvis is the so-called normal female pelvis. Its inlet is either slightly oval, with a greater transverse diameter, or round. The interior walls are straight, the subpubic arch wide, the sacrum shows an average to backward inclination, and the greater sciatic notch is well rounded. Because this type is spacious and well proportioned there is little or no difficulty in the birth process. Caldwell and his co-workers found gynaecoid pelves in about 50 per cent of specimens.
Fig: White lines in the diagrams at right show the greatest diameters of the pelves at left.
Ideal shape, best chances for normal vaginal delivery.

31. Anthropoid pelvis It is ape-like type.
All anteroposterior diameters are long.
All transverse diameters are short.
Sacrum is long and narrow.
Sacro-sciatic notch is wide.
Subpubic angle is narrow (<900 )
prominent ischial spines
is a female pelvis with masculine features, including a wedge or heart shaped inlet caused by a prominent sacrum and a triangular anterior segment. The reduced pelvis outlet often causes problems during child birth. In 1939 Caldwell found this type in one third of white women and one sixth in non-white women.

32. Android pelvis It is a male type.
Inlet is triangular or heart-shaped with anterior narrow apex.
Side walls are converging (funnel pelvis)
Projecting ischial spines.
Sacro-sciatic notch is narrow.
Subpubic angle is narrow <90o
The anthropoid pelvis is characterized by an oval shape with a greater anteroposterior diameter. It has straight walls, a small subpubic arch, and large sacrosciatic notches. The sciatic spines are placed widely apart and the sacrum is usually straight resulting in deep non-obstructed pelvis. Caldwell found this type in one quarter of white women and almost half of non-white women.

33. Platypelloid pelvis It is a flat female type.
All anteroposterior diameters are short.
All transverse diameters are long.
Sacro-sciatic notch is narrow.
Subpubic angle is wide
The platypelloid pelvis has a transversally wide, flattened shape, is wide anteriorly, greater sciatic notches of male type, and has a short sacrum that curves inwards reducing the diameters of the lower pelvis. This is similar to the rachitic pelvis where the softened bones widen laterally because of the weight from the upper body resulting in a reduced anteroposterior diameter. Giving birth with this type of pelvis is associated with problems. Less than 3 per cent of women have this pelvis type.

34. Pelvic floor

35. Pelvic floor
The tissues closing down the pelvic outlet (muscles and fasciae)
Function
- providing support for pelvic organs, e.g. the bladder, rectum, the uterus.
- maintenance of continence
Anterior part (urogenital triangle)
urethra and vagina pass through
Posterior part (anal triangle)
rectum pass through

36. Pelvic floor Outer layer Bulbocavernosus muscle (球海绵体肌)
Ischiocavernosus muscle (坐骨海绵体肌)
Superficial transverse perineal muscle (会阴浅横肌)
External anal sphincter (肛门外括约肌)
mid layer
urogenital diaphragm (泌尿生殖膈)

37. Pelvic floor Inner layer (pelvic diaphragm 盆膈)
the main support of the pelvic floor
formed by the levator ani and coccygenus muscles and covering fasciae.
Levator ani: （肛提肌)
pubococcygenus (耻尾肌),
iliococcygenus (髂尾肌),
puborectalis (坐尾肌)

38. PC IC

39. Levator ani Pubococcygenus (PC ) Iliococcygenus (IC)
-a hammock-like muscle
-stretches from the pubic bone to the coccyx (tail bone)
-controls urine flow and position the baby's head during childbirth.
Iliococcygenus (IC)
- arises from the ischial spine, super ramus of the pubis, and is attached to the coccyx
- Help for vaginal contraction
Puborectalis (PR) sphincter ani externus
- arise from the lower part of the symphysis pubis,and the superior fascia of the urogenital diaphragm , meet with the corresponding fibers of the opposite side around the lower part of the rectum, and form for it a strong sling.
- Relaxation reduces the angle between rectum and anus, allowing defecation in conjunction with relaxation of the internal and external sphincters.

40. Pelvic floor
Perineum
general conception: the tissues closing down the pelvic outlet
Clinical conception: the tissues between vaginal and anus.
- thickness: 3-4cm
- the outlayer support for pelvic floor

41. SUMMARY Bones Joints Ligaments planes of the pelvis
Types of the female pelvis
Pelvice floor

42. END