Anatomy of Female Pelvis, Fetal Skull and Clinical Pelvimetry

1. FUNCTIONAL ANATOMY OF
FEMALE PELVIS AND THE FETAL
SKULL
BY
BITEW MEKONNEN
(BSc, MSc, MBA)
bitewm@gmail.com

2. Functional Anatomy of Female Pelvis
and the Fetal Skull
• 2.1.Review of the anatomy and physiology
Reproductive system
• 2.1.1.Anatomy of internal and external
genitalia
• 2.2.The female pelvis
• 2.2.1.Contents of the pelvis cavity
• 2.3.The menstrual cycle
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3. Learning Objectives
• At the end of this chapter the students will be able
to:
- Describe anatomy of the Female pelvis and Female
external genitalia
- Mention parts of fetal skull with its features.
- Differntiat organs contained in the pelivic cavity.
- Describe characteristic of menustral cycle and its
disorder
- List anatomy of female breast
- Define puberity and its featuers.
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4. 2.1.Review of the anatomy and
physiology Reproductive system
Introduction
• It is mandatory to know the anatomy and
physiology of the female reproductive
system to manage obstetric and
gynecologic problems.
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5. 2.1.1. Anatomy of internal and
external genitalia
• External female genitalia (vulva or pudendum )
• The vulva includes mons pubis, labia majora,
labia minora, clitoris, vestibule and perineum
which are all visible on external examination.
• It is bounded anteriorly by the mons pubis,
laterally by the labia majora and posteriorly by
the perineum.
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6. External genitalia
– Collectively referred to as the vulva or the pudendum
– It includes
The mons pubis (Veneris)
Labia majora
Labia minora
Clitoris
The vestibule
The fourchette
The perineum
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7. Superficial Perineum Female
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8. Superficial Perineum Female
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9. Female Reproductive Structures
• The structure of the uterus, uterine tubes, and ovaries is the basis
for understanding reproductive cycles and implantation
Uterus
• The uterus ([L.],
womb) is a thick-
walled, pear-
shaped muscular
organ.
• Parts –
Female Reproductive Structures
• Fundus
• Body
• Cervix
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10. Female reproductive structures
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11. Uterus: Parts
1 .Fundus
• Is the part lying above the level of openings of the uterine tubes
 The area where the tubes join the uterus is called cornu (uterine horn)
2. Body
• Forms 2/3 of the uterus and extends from
the tubal openings to a constricted portion
3. Cervix cylindrical inferior one third
• The most fixed the part extends between the
isthmus and the vaginal opening of the uterus
 It is divided into two by the upper wall of the vaginal
A.Supravaginal part – part above the vagina
B. Vaginal part (portion vaginalis)- communicates
with the vagina through the external astium or os
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12. • The walls of the body of the uterus consist of three layers
Perimetrium -thin external layer
Myometrium- thick smooth muscle layer
Endometrium- thin internal layer
12
Uterus …
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13. 13
Uterus …
 an outer connective tissue layer,
continuous with the ligaments, which is
adventitia in some areas, but largely a
serosa covered by mesotheliumFirmly
attached to the myometrium
Myometrium
 The thick highly vascular smooth muscle
layer
Endometrium
 A mucosa, the endometrium, lined by
simple columnar epithelium
 has both ciliated and secretory cells, the
latter forming numerous tubular uterine
glands
Perimetrium
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14. 14
Endometrium
• The endometrium can be
subdivided into two zones
1. Basal layer
 Adjacent to the myometrium
 Contains highly cellular
lamina propria and the deep
basal ends of uterine glands
 has its own blood supply and
is not sloughed off during
menstruation (remains
relatively unchanged)
2. Superficial functional layer
 Contains less cellular lamina
propria
 Richer in ground substance,
most of the length of the
glands
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15. 15
Endometrium
I. A thin, compact layer
consisting of densely packed,
connective tissue around the
necks of the uterine glands
II. A thick, spongy layer
composed of edematous
connective tissue containing
the dilated, tortuous uterine
glands
• During the luteal phase of the menstrual cycle, two layers of the
functional layer can be distinguished microscopically
• The functional layer undergoes
profound changes during the
menstrual cycles
– Disintegrate and are shed
during menstruation and after
parturition (delivery of a baby)
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16. Uterine tubes
• Also known as oviducts (formerly called fallopian tubes)
• It is lined with secretory epithelium for nourishment of ovum
Extent
• From the lateral angles/cornu of the uterus to uterine ends of the
ovaries
– Length = ~10 -12 cm : Diameter = ~ 1 cm
Functions of Uterine Tubes
• Carry oocytes
• Sperms (ampulla of the uterine tube )
• Conveys the cleaving zygote to the uterine cavity
The ova are propelled to the uterus along this
tube, partly by peristalsis
and partly by cilial action.
Female reproductive structures …
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18. Uterine tubes: Parts - 4
1. Infundibulum 3. Isthmus
2. Ampulla 4. Intramural
(uterine) part
Infundibulum
• Is a funnel-shaped part close to
the ovaries
• It contains the abdominal or pelvic
opening surrounded by thin irregular
finger like processes, the fimbrae
• The fimbrae catch a discharged ovum
and passes it to the tube
 The largest of this fimbrae attached to
the tubal end of the ovaries is called
ovarian fimbrae (fimbrae ovarica)
Length = 1cm)
ᶲ = 3mm
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19. Ampulla
• Is the thin walled, longest part that
has a widest diameter
• It follows a slightly tortuous course
b/n infundibulum & isthmus
Isthmus
• Is the part between the widest
part, ampulla, and the uterus
• Is narrower and thicker than
the ampulla
Uterine tubes …
Length = 5cm)
ᶲ = 4mm
Length = 3cm)
ᶲ = 2 mm
Intramural part
• Is the part with in the wall of the uterus
 It is the narrowest part of the tube
• Its opening into the uterine cavity
Length = 1cm)
ᶲ = 1 mm
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20. The female reproductive structures ….
A. Estrogen (sex hormone)
 secreted from Graffian follicle
 responsible for 20 female sex characters
B. Progesterone (pregnancy hormone)
 secreted from corpus luteum after
ovulation for some time
 responsible for maintenance of pregnancy by increase the thickness
and vascularity of uterine endometrium 20
Ovaries
• Are female sex glands
• lie in the side wall of the
pelvis (in the ovarian fossa)
• Produce oocytes
• Secretes two hormones:
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21. 2.2.The Bony Pelvis
• The Bony Pelvis
– composed of four bones
• Sacrum & coccyx
• Two innominate bones (ilium, ischium, & pubis)
– False (greater) & True (lesser) pelvis
• By the pelvic brim
– True pelvis
• Divided into three planes
1. Pelvic inlet
2. Mid pelvis
3. Pelvic outlet
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24. Superior view of the female pelvis
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25. Anterior view of the female pelvis
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26. Pelvic inlet
• Boundaries
– Post - sacral promontory, anterior ala of sacrum
– Ant - pubic symphysis (PS)
– Lat - linea terminalis
• Normal diameters
– Transverse - 13 cms
– Anteroposterior ( Conjugate)
• True conjugate - 11cms
– Sacral promontory - upper border of PS
• Diagonal conjugate - 12cms
– Sacral promontory - lower border of PS
• Obstetric conjugate - 10 - 11cms
– Sacral promontory - posterior superior portion of PS
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29. Mid & Outlet Pelvis
• Mid cavity
– Bispinous diameter - 10cms
• Smallest pelvic diameter
– AP diameter - 11.5cms
• Symphysis pubis to junction of S4 & S5
• Pelvic outlet
– AP diameter - 9.5 - 11cms
• Coccyx to symphysis pubis
– Transverse (intertuberous) diameter - 11cms
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31. Average & Critical Limit Values for Pelvic
Measurements by X-ray Pelvimetry
DIAMETER
AVERAGE
VALUE
CRITICAL
LIMIT[*]
Pelvic inlet
Anteroposterior
(cm)
12.5 10.0
Transverse (cm) 13.0 12.0
Pelvic midcavity
Anteroposterior
(cm)
11.5 10.0
Transverse (cm) 10.5 9.5
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32. Pelvic Shapes
• The Caldwell-Moloy classification
– based on measurement of the greatest transverse
diameter of the inlet & its division into anterior &
posterior segments.
• The character of the posterior segment determines the type of
pelvis, and
• The character of the anterior segment determines the tendency
– Four pelvis types
1. Gynecoid
2. Anthropoid
3. Android
4. Platypelloid
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37. Estimation of Pelvic Capacity
1. X-Ray Pelvimetry
§ Limited value in the Mx of labor with a cephalic
presentation
2. CT Scanning
3. MRI
4. Clinical pelvimetry
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38. Clinical Pelvimetry
• Clinical pelvimetry
– is currently the only method of assessing the
shape & dimensions of the bony pelvis in labor
– involves the assessment of the pelvic inlet,
mid pelvis, & pelvic outlet.
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39. Pelvic Inlet
1. Diagonal conjugate
• > 12cms - adequate pelvic inlet for a normal size fetus
• OC = DC - 1.5 to 2cms
• OC < 10cms or DC < 12cms - contraction
2. Sacral promontory
• Easily reachable or prominent - contraction
3. Head fit test
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40. How to measure the Diagonal Conjugate
• Patient placed in dorsal position
• Examining fingers
– Mobilize in upward direction following the anterior
sacral curvature
• So as to reach the promontory the elbow & wrist are to be
depressed sufficiently
• The point at which the bone recedes from the fingers is the
sacral promontory
– Mobilize under the symphysis pubis & place a mark on
the index finger
– Remove fingers & measure the distance between the
marking & tip of the middle finger
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42. Pelvic inlet
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44. Mid pelvis
• Contraction suspected
1. Ischial spines - prominent
2. Pelvic sidewalls - converge
3. Sacral concavity - shallow
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46. Pelvic outlet
• Inter tuberous diameter
• Estimated by placing a fist on the perineum to measure the
distance between the ischial tuberosities
• < 8cms - contraction
• Subpubic arch
– Adequate if it accommodates the palmar aspect of two fingers
• Subpubic angle
– Adequate if it roughly corresponds to the fully abducted thumb &
index finger
– Narrow - if it roughly corresponds to the fully abducted middle & index
finger
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49. 3
0
2
2.Engagement;descent, flexion
6. Restitution (external rotation)
3. Further descent, internal rotation
4. Complete rotation, beginning
extension
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50. Pelvic floor Or Pelvic diaphragm
• The pelvic floor or diaphragm is a muscular
floor that demarcates the pelvic cavity and
perineum.
• Its strength is inforced by its associated
condesed pelvic fascia, therefore, it is
important for pelvic organs protection.
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51. Functions: -
• It supports the weight of the abdominal and
pelvic organs
• The muscles are responssible for the voluntary
control of micturation, defication and play an
important part in sexual intercourse.
• It infulences the passive movement of the
fetus through the birth canal and relaxes to
allow its exit from the pelvis.
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52. The main important muscels of pelivic
floor are:
• Levater ani muscles are arising from the lateral
pelveic wall and decussate in the midline
between the urethra, the Vagina and rectum.
• It contains pubococcygeous muscle, ileo
coccygeus and pubo rectalis.
• Pubococygeous muscle is constructed in such
away that it can expand enough for child bith and
contract the pelvis supported
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53. 2.2.1. Contents of the pelvis cavity
Pelvic Viscera
• include the:
• urinary bladder and parts of the ureters
• the reproductive system
• the distal part of the alimentary tract (rectum).
• Although the sigmoid colon and parts of the small bowel
extend into the pelvic cavity, they are abdominal rather
than pelvic viscera.
• The sigmoid colon is continuous with the rectum anterior
to S3 vertebra.

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55. The Fetal Skull
• The fetal head is the most difficult part to deliver
whether it comes first or last.
• It is large in comparison with the ture pelvis
and some adptation between skull and pelvis must
take place during labour.
• An understanding of the landmarks and
measurements of the fetal skull enables to
recognize normal presentation and positions and
to facilitate delivery with the least possible trauma
to mother and child.
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57. Peculiarities of the Fetal Skull
• The fetal skull anatomy and dimensions are very
important parameters in labor outcome
• This is because the fetal skull is proportionally the
largest and least pliable structure of the fetal
anatomy
• Labor obstruction usually occurs at the level of
the fetal skull
• Clear understanding of fetal skull anatomy and
identification of important landmarks is
important in assessment of labor progress and
diagnosis of abnormalities of labor
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58. Bones of the Vault
• There are five main bones in the vault of the fetal
skull.
A. The occipital bone lies at the back of the head
and forms
the region of the occiput.
B. The two parietal bones lie on either side of the
skull.
C. The two frontal bones from the forehead or
sinciput.
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59. Peculiarities of the Fetal Skull- Landmarks
Fontanels Sutures
•Anterior fontanel (Bregma) - rhomboid
shape space at the junction of the two
parietal and frontal bones . Not readily
felt during vaginal exam in a well flexed
vertex. But easily felt in a brow and face
presentation. Differentiated from the
posterior fontanel by its four angles
•Posterior fontanel- a triangular space at
the junction of the occipital and two
parietal bones. Has three angles. Useful as
the anatomical landmark as the
denominator of fetal position in vertex
presentations. Easily felt in vertex
presentations.
•Saggital suture- opening between the
two parietal bones. Its central positioning
is used to diagnose fetal asynclitism. Also
used as the landmark for locating the
fontanelles.
•Lambdoid sutures- opening between the
two parietal bones and the occipital bone
posteriorly.
•Coronal sutures- opening between the
parietal bones and the frontal bone
anteriorly.
•Other non-significant sutures as well.
•Significance of these openings is believed
to be the provision of pliability of the fetal
skull allowing for growth of the fetal and
childhood brain.
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61. Important fetal skull diameters
Diameter Measurement landmarks Term
fetus
Fetal presentation
Biparietal
diameter
Between the two parietal
eminences
9.5cms Largest transverse diameter of
the fetal skull in all cephalic
presentations
Sub-occipito
bregmatic
Lowest point of occipital bone
to the middle of anterior
fontanel
9.5cms Vertex presentation
Sub-mento
bregmatic
Just behind the mentum to
the center of anterior fontanel
9 cms Face presentation
Mento-
vertical
Mentum to the highest point
of the vertex
13.5
cms
Brow presentation
The BPD is the transverse diameter in all the cephalic presentations including vertex, face
and brow as it is the largest transverse diameter of the fetal skull.
Measurements represent the averages form a term fetus.
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66. Fetal molding and types
• Fetal molding refers to the process of overlap of fetal skull
bones on each other at the location of certain sutures
usually due to the pressure against the birth canal during
labor
• Molding allows for a reduction in fetal skull diameters by
upto 6mms to 1 cms which can be significant enough to
allow progress to delivery in cases of cephalo-pelvic
disproportion
• Excessive molding can also lead to trauma
• Assessment of molding is one of the parameters used to
diagnose cephalo-pelvic disproportion
• Two types of molding- parieto-parietal (PP) and occipito-
parietal (OP)
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67. Degrees of fetal skull molding during labor
Degree Description Significance
0 Skull bones separate from each other No abnormality
+ 1 Skull bones approximate each other but do
not overlap
No abnormality
+ 2 Skull bones overlap but can be separated by
the examining hand
Can indicate obstruction if
in early labor or at high
station
+ 3 Skull bones overlap and cannot be separated
by the examining finger
Indicator of obstruction
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69. Figure 6- Landmarks of fetal skull for determination of fetal position.
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70. Figure-7 Presenting diameters of the average term fetal skull.
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72. Caput Succedaneum
• Caput succedaneum is the development of
edema on the fetal skull due to the pressure
of the cervix impeding venous outflow from
the scalp
• It usually recedes hours after delivery
• In cases of obstructed labor caput can grow to
excessive sizes and become one of the
indicators of obstruction
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74. Puberty
• Puberty - the age of sexual maturation
• ThIs is the stage of life at which secondary sexual
characterstics appear.
• Girls begin dramatic development and maturation of
reproductive organs at approximately age 12 to
13 years, Although the mechanism that initiates this
dramatic change is not well understood, the hypothalamus
under the direction of the centeral nerveous system may
initiate or regulate mechanism set to “turn on” gonadal
functioning at this age.
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75. • There is a wide variation in the times that
adolescents move through developmental stages;
however the sequential order is fairly constant.
• In girls pubertal changes typically occur in
the order of:
- Marked physical growth
- Increase in the transvers diameter of the pelvis
- Breast development
- Growth of pubic and axillary hair
- Vaginal secretion /Menarche
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76. 2.3.The menstrual cycle
• A menstrual cycle (also termed a female reproductive cycle)
can be defined as periodic uterine bleeding in response to
cyclic hormonal changes or a serioes of changes that occur
on the ovary, uterus, and cervix in response to hormonal
change.
• The average age at which menarche (the first
menustral period) occurs at the average age of 12.8 years.
• This may occur as early as age 9 or as late as age 17 years.
• The purpose of a menstrual cycle is to bring an ovum to
maturity and renew a uterine tissue bed that will be
responsive to its growth should it be fertilized.
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77. • The average age of onset of menstrual cycles
is 21 to 35 days.
• The accepted average length is 28 days.The
length of the average menstrual flow is 1-9
days and the average
length is 5 days.
• Amount of flow is from spotting to 80 ml on
average.
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78. • Four body structures that are involved in the
normal physiology of the menstrual cycle are:
- The hypothalamus
- The pituitary gland
- The ovaries and
- The uterus.
- Cervix
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79. • For a menstrual cycle to be complete, all four structures must
contribute their part, in activity from any part will result in an
incomplete or ineffective cycle.
• Some women have symptoms of anxiety, fatigue, abdominal
bloating, headache, appetite disturbance, irritability and
depression in pre-manustural period.
• Some women may experience abdominal pain during ovulation
and the release of accompanying prostaglandins.
• Some even notice irritation when a drop or two of follicular fiuid
or blood spills in to the abdominal cavity.
• This pain, called mitlelschmerz may range from a few sharp
cramps to several hours of discomfort.
• It is typically felt on either side of the abdomen (near an ovary)
and may be accompanied by scant vaginal spotting.
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80. Ovulation
80
Defination
• A process in which secondary oocyte is released from the ovary.
Time of Ovulation:
• 14 days before the next menstruation (for woman with regular 28 days cycle)
• Around midcycle, the ovarian follicle,
under the influence of FSH and LH,
undergoes a sudden growth spurt,
producing a cystic swelling or bulge
on the surface of the ovary.
 A small avascular spot, the stigma, soon
appears on this swelling.
• Before release (ovulation), the
secondary oocyte and some cells of
the cumulus oophorus detach from
the interior of the distended follicle.
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81. Surface bulge
Stigma
1. High level of
estrogen to -
hypothalamus &
Ant.pituitary
LH. surge
Ovary
Ovulation occurs
81
Ovulation
• Ovulation is triggered by a surge of LH production
– Usually follows the LH peak by 12 to 24 hours.
– The LH surge, elicited by
the high estrogen level in
the blood, also appears
to cause the stigma to
balloon out, forming a
vesicle
• The stigma soon
ruptures, expelling the
secondary oocyte with
the follicular fluid
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82. 1.High level of
estrogen to -
hypothalamus &
Ant.pituitary
LH. surge
Ovary
Ovulation occurs
82
Ovulation …
• The expelled secondary
oocyte is surrounded by the
zona pellucida and one or
more layers of follicular cells,
which are radially arranged
as the corona radiata,
forming the oocyte-cumulus
complex.
• The LH surge also seems to
induce resumption of the first
meiotic division of the primary
oocyte
• Hence, mature ovarian follicles
contain secondary oocytes
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83. • Middle pain and Ovulation
 A variable amount of abdominal pain,
mittelschmerz (German, mittel, mid + schmerz,
pain), accompanies ovulation in some women
 In these cases, ovulation results in slight bleeding
into the peritoneal cavity, which results in sudden
constant pain in the lower abdomen
 Mittelschmerz or Middle pain may be used as a
symptom of ovulation
Ovulation…
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84. C. Corpus Luteum (CL)
84
• Causing the endometrial glands
to secrete and prepare the
endometrium for implantation
of the blastocyst
• Shortly after ovulation,
Under LH influence, the walls
of the ovarian follicle and
theca folliculi collapse and
are thrown into folds they
develop into a glandular
structure, the corpus luteum
• CL produces progestron and
estrogen
 Progesteron-is important for
endometrial thickening
• It is a collapsed wall of ovarian follicle and theca cells
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85. Types of corpus luteum 1. corpus luteum of pregnancy
2. corpus luteum of menstruation
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86. • If fertilization occurs
– CL becomes enlarges to form corpus luteum of pregnancy
(corpus graviditatis) and continues its hormone production
– Its degeneration is prevented by human chorionic
gonadotropin, a hormone secreted by the syncytiotrophoblast
of the blastocyst
• The corpus luteum of pregnancy remains functionally
active throughout the first 20 weeks of pregnancy
– By this time, the placenta has assumed the production of
progesterone necessary for the maintenance of pregnancy
• If fertilization doesn’t occur
– The corpus luteum degenerates 10 to 12 days after ovulation
• It is then called a corpus luteum of menstruation i.e white
scar tissue in the ovary (corpus albicans) and its hormone
production level decreases 3-86
Corpus luteum(CL) …
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87. Duration of ovarian cycle
Ovarian cycle persist
• Throughout the
reproductive life of
women and terminate
at menopause
No ovarian cycle
• During pregnancy
• At menopause
– Menopause, the permanent
cessation of menstruation,
usually between the ages of
48 and 55.
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88. Phases of menstrual cycle
• Proliterative phase: - Immediately following a
menstrual flow (occurring the first 4 or 5 days of a
cycle), the endometrium, or lining of the uterus is very
thin, only approximately one cell
layer in depth.
• Secratory phase- What occurs in the next half of in a
menstrual cycle depends on whether the released
ovum meets and is fertilized by spermatozoa.
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89. • If fertilization does not occur, the corpus luteum in the
ovary begins to regress after 8 to 10 days.
• As it regresses, the production of progesterone and
oestrogen decreases.
• With the withdrawal of progesterone stimulation, the
endometrium of the uterus begins to degenerate (at
approximately day 24 or day 25 of the cycle).
• The capillaries rupture, with minute hemorrhage, the
endometrium sloughs off, and menustration
starts.
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91. • The monthly changes in the internal layer of the uterus
constitute the endometrial/uterine cycle, commonly
referred to as the menstrual cycle or period
– The later is because -menstruation (flow of blood from the uterus) is
an obvious event
• Is the time during which the oocyte matures, is ovulated, and
enters the uterine tube
• The hormones produced by the ovarian follicles and corpus
luteum (estrogen and progesterone) produce cyclic changes
– The endometrium is a "mirror" of the ovarian cycle because it
responds in a consistent manner to the fluctuating concentrations of
gonadotropic and ovarian hormones
• The average menstrual cycle is 28 days (In 90%, +5)
• Day 1 of the cycle designated as the day on which menstrual flow
begins
Menstrual (Endometrial) Cycle
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92. Phases of menstrual cycle
92
Menstrual
Phase.
Proliferative
phase
Luteal Phase
4 to 5 days
9 days
14/13 days
• Changes in the estrogen and progesterone levels cause cyclic
changes of the endometrium
• The menstrual
cycle is a
continuous process
divided into three
main phases
 Each phase
gradually passes
into the next one
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94. Phases of menstrual cycle
94
• The functional layer of the uterine wall is sloughed off and
discarded with the menstrual flow-menses (monthly bleeding)
– The blood discharged through the vagina is combined with small pieces of
endometrial tissue.
 Blood + part of endometrium
• After menstruation, the eroded endometrium is thin
1.Menstrual phase
• Usually lasts 4-5 day
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95. Phases of menstrual cycle ….
2. Proliferative Phase
95
• The proliferative (follicular, estrogenic) phase ~ 9 days
– Coincides with growth of ovarian follicles and is
controlled by estrogen secreted by these follicles.
• Early during this phase, the surface epithelium reforms and covers
the endometrium (it is a phase of repair)
• The glands increase in number and length, and the spiral arteries
elongate
• There is a two- to three fold increase in the thickness of the
endometrium and in its water content
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3. Luteal (secretory, progesterone) phase
• Lasting approx.13 days, coincides with functioning, and growth of
corpus luteum
• The progesterone produced by the corpus luteum stimulates the
glandular epithelium to secrete a glycogen-rich material.
 Direct arteriovenous anastomoses are prominent features of this stage
Phases of menstrual cycle ….
• Because of the influence of progesterone
and estrogen from the corpus luteum -
increased fluid in the connective tissue
– The endometrium thickens
• As the spiral arteries grow into the
superficial compact layer, they become
increasingly coiled
– The glands become wide, tortuous, and saccular
– The venous network becomes complex and large
lacunae (venous spaces) develop.
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97. What happen to emdometrial cycle if;
Fertilization does not occur
Fertilization occurs
• Cleavage of the zygote and blastogenesis
(formation of blastocyst) occur
 The blastocyst begins to implant on approximately the
sixth day of the luteal phase (day 20 of a 28-day cycle)
• The corpus luteum degenerates
 Estrogen and progesterone levels fall …. and
 The secretory endometrium enters an ischemic phase … then
 Menstruation occurs
• Human chorionic gonadotropin, keeps the corpus
luteum secreting estrogens and progesterone
 The luteal phase continues and menstruation
does not occur
FSH
LH
0 7 14 21 28 days
Proliferative
phase
Secretory phase
Menstrual &
recovery
phase

98. Pregnancy Phase
• If pregnancy occurs, the menstrual cycles cease and the
endometrium passes into a pregnancy phase.
• With the termination of pregnancy, the ovarian and
menstrual cycles resume after a variable period (usually 6 to
10 weeks if the woman is not breast-feeding her baby).
• If pregnancy does not occur, the cycles normally continue
until menopause
Ischemic Phase
• The ischemic phase occurs when the oocyte is not
fertilized.
• Ischemia (reduced blood supply) occurs as the spiral
arteries constrict, giving the endometrium a pale
appearance
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99. How do hormonal contraceptives work????
• Diagram depicts positive and negative
feedback loops seen with the
hypothalamic-pituitary-ovarian axis.
Pulsatile release of gonadotropin-
releasing hormone (GnRH) leads to
release of luteinizing hormone (LH)
and follicle-stimulating hormone
(FSH) from the anterior pituitary.
• Effects of LH and FSH result in follicle
maturation, ovulation, and
production of the sex steroid
hormones (estrogen, progesterone,
and testosterone).
• Rising serum levels of these
hormones exert negative feedback
inhibition on GnRH and gonadotropin
release.
• Sex-steroid hormones vary in their
effects on the endometrium and
myometrium as discussed in the text.
• Inhibin, produced in the ovary, has a
negative effect on gonadotropin
release.
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100. 4/6/2022 100
BREAST

101. The Female Breast Anatomy
• The female breasts
The female breasts, also known as the mammary glands, are
accessory orgns of reproduction.
• Size The size varies with each individual and with the stage of
development as well as with age. It is not uncommon for one breast
to be little or larger than the other.
• Alveoli: Containing the milk- secreting cells.
• Lactifierous tubules: small ducts which connect the alveoli.
• Lactifierous duct: a central duct into which the tubules run.
• Amplulla: the widened-out portion of the duct where milk is
stored. The ampullae lie under the areola.
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Female Reproductive System
• Mammary Glands
• Each mammary gland is made up or 15-25 lobes that
radiate around the nipple
• Each lobule is connected by lactiferous ducts that open
into the nipples (gets milk to nipple)
• Lobes contain
– Alveolar Glands produce milk during lactation
• Lobes are separated by connective tissue and fat
• There are suspensory ligaments in the connective
tissue that attach the breasts to the pectoral muscles
of the chest.

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105

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106

107. Review Questions
1. . List the main femal gentail orgns that are important in the
process of reproduction.
2. Mention the main pelvic land mark that are important in
obstatrics during pregnancy and labour process.
3. What are the obstratrical importancy of fontanalles and sutures in
the process of labour mangment.
4. - Describe anatomy of the Female pelvis and Female
external genitalia
5. Mention parts of fetal skull with its features.
6. Differntiat organs contained in the pelivic cavity.
7. Describe characteristic of menustral cycle and its disorder
8. List anatomy of female breast
9. Define puberity and its featuers.
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108. Reference:-
1. Atlas of human anatomy Williams
2. Essentials of obstetrics and gynecology – Haker/Moore
3. Brie human anatomy- part 2-Maseresha A buhay
4. Williams gynecology and
5. Williams obstetrics 24th edition
6. current obstetric and gynecology -9th edition
7. Clinical practice for midwifery guide line and women’s
2006 – 2009
8. Bennett. (1993): Myles Text Book of Midwives, 12th
edition. Great Britain.
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109. The End
THANK YOU
Bitew Mekonnen
bitewm@gmail.com
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