Download Female Reproductive System

Female Reproductive System
Female Pelvis (sagittal section)
ureter
common iliac
artery & vein
uterine tube
uterine fundus
uterine cavity
recto-uterine pouch
(cul de sac/Douglas’
sac)
vesico-uterine pouch
urinary bladder
urethra
mons pubis
clitoris
labium minus
labium majus
posterior fornix
cervix
rectum
vagina
anus
introitus vaginalis
https://www.youtube.com/watch?v=qCLmR9YY7o
Oogenesis
• Mitosis of oogonia during fetal life produces a diploid primary
oocyte
• Meiosis I begins before birth, it won’t be completed until the
girl reaches puberty.
• Meiosis I is completed after puberty, it produces a secondary
oocyte and a first polar body, both are haploid cells.
• Secondary oocyte is ovulated in metaphase of meiosis II,
process will be completed if fertilization occurs; at completion
of meiosis II the mature gamete (a haploid cell) is ready to fuse
with the male gamete (also a haploid cell); a second polar body
is produced. Fertilization will produce a diploid cell, the
Conceptus or Zygote.
Oogenesis, Ovulation
Ovulation
• Each almond-sized ovary hosts 100.000 to 200.000 primordial follicles
• During each ovarian cycle several of these primary follicles develop into
secondary follicles
• Eventually one secondary follicle develops into a tertiary follicle a.k.a.
“Graafian follicle” “containing an oocyte.
• The follicular sac ruptures releasing the oocyte (ovum), this event
called “Ovulation”
• After ovulation the empty follicle becomes a gland called Corpus
Luteum that secretes progesterone and also moderate amounts of
estrogen. Progesterone plays an important role in the preparation of
the uterus for pregnancy
• If the oocyte is not fertilized, the corpus luteum becomes an atretic
structure named Corpus Albicans; the internal lining of the uterus
(endometrium) sheds and is eliminated as part of the menses.
Uterus, Oviducts, Ovaries
Oviducts
• The two uterine tubes called oviducts or Fallopian tubes have
at their lateral ends fingerlike projections called fimbriae
• These fimbriae sweep over the surface of the ovary and trap
the ovum during ovulation bringing it toward the slightly
expanded portion of the oviduct, called infundibulum
• Once inside the oviducts, the ovum is moved toward the
uterus by the tube peristalsis and the action of the cilia in the
tubal lumen.
• The oviducts widen along their length in the ampulla and
then narrow at the isthmus, at their point of entrance to the
uterus
• Fertilization of the ovum usually occurs at the distal third of
the tubes, the conceptus is then pushed toward the uterus.
Uterus
• A pear-shaped muscular sac, located between the urinary
bladder and the rectum.
• It is around 7.5 cm long and a maximum diameter of 5 cm and
weights around 30-40 g
• It consists of three major regions :
• The fundus, the superior portion, located right over the level
of entrance of the oviducts
• The body, the most extense portion and the elongated cervix,
its portion that shows at the vagina
• In its normal position the uterus tilts anteriorly maintaining its
cavity mostly aligned with the cervical canal and covering
most of the superior and posterior portions of the urinary
bladder. This usual bending uterine attitude is called
anteversion and it is considered the normal position of the
uterus.
A)
B)
C)
D)
E)
F)
G)
H)
I)
J)
K)
L)
Uterine (Fallopian) tube
Broad ligament
Uterine fundus
Uterine cavity
Uterine body
Uterine isthmus (segment)
Uterine cervix
Vaginal lateral fornices
Introitus vaginalis
External Os of cervix
Cervical canal
Internal Os of cervix
C
A
Female Genitalia
Anterior view
B
D
A
E
B
F
L
K
G
J
V
a
g
i
n
a
H
I
Uterine Positions
Anteverted (usual, “normal”)
Retroverted: Abnormal,
prone to prolapse
Uterus
• The tubular cervix projects into the vagina, the
vaginal folds around the cervix are called each one a
vaginal fornix.
• The external cervical orifice, called external os
communicates with the cervical canal which opens
into the cavity of the uterus via an internal os.
• The uterine body is the broadest part of the uterine
cavity, the usual site for the implantation of the
placenta during pregnancy and the area where the
developing fetus resides.
Uterus: Suspensory Ligaments
• A double layered fold of peritoneum called the
mesovarium holds the ovaries to the broad ligament of
the uterus
• The suspensory ligaments hold the ovaries to the
pelvic wall
• The ovarian ligaments hold the ovaries to the uterus
• The round ligaments extend laterally from the ovaries
and provide posterior support.
The Uterine Wall
• The uterine wall consists of three main tissue layers:
• The perimetrium, the outer layer, is an extension of
the visceral peritoneum and hence called a serosa.
• The myometrium is the thick middle layer, composed
of three layers of smooth muscle, responsible for the
powerful contractions during labor
• The endometrium is a double epithelial layer, its
inner basilar zone produces a new functional zone
each month. The outer functional zone is a very
active glandular tissue able to support an implanted
embryo. It sheds on every cycle and is discarded as
part of the menses
Vagina
• An elastic, distensible muscular tube, around 7.5 -9 cm long
extending from the cervix to the vestibule, a space bounded
by the female external genitalia.
• The shallow recess surrounding the protruding cervix is called
the vaginal fornix
• The vagina lies parallel to the rectum which is posterior to her.
Anteriorly, the urethra extends along the superior end of the
vagina to open in the area of the vestibule
• The vagina has three major functions:
• Serves as a passageway for the menses
• Is the female copulatory organ
• Forms the inferior portion of the birth canal
The Vulva
Female External Genitalia
• The vulva includes the following structures:
• Mons Pubis, a pad of adipose tissue over the pubic symphysis,
usually covered by pubic hair
• The labia majora, (singular: labium majus), two longitudinal folds of
skin, extending from the pubis to the posterior angle of the vulva
• The labia minora, (singular: labium minus), two small folds of skin
covered internally by a mucosa, they extend longitudinally and
guard the vestibule, the place where the vagina opens.
• The clitoris, is a small cylindrical mass of erectile tissue, the
analogous of the penis; it also has a prepuce covering its distal tip
called the glans
• The entrance to the vagina, the introitus vaginalis is often covered
by an elastic epithelial fold called the hymen
• The female urethral opening, located at the vulvar vestibule, close
to the anterior wall of the vagina, midway between the clitoris and
the introitus vaginalis. Para-urethral exocrine glands (Skene’s
glands) surround the female urethra.
Female Mammary Gland
• The female mammary glands are modified sweat glands.
They complete their anatomical development at puberty,
under the stimulus of estrogens.
• Fat deposition is the main contributor to the size of the
breast, and its size is not related with the capacity of the
organ to produce milk for lactation of the offspring.
• Each gland consists of 15 to 20 lobes of glandular tissue
separated by fat and connective tissue. Each lobe contains
smaller lobules formed of milk-secreting cells called alveoli.
• Lactiferous ducts drain milk from the lobules toward the
lactiferous sinuses. These sinuses empty the milk to a raised
portion of the breast called the nipple.
• A circular pigmented area of skin called the areola surrounds
the nipple.
Breast
Breast Quadrants
Frequency of breast
cancer by quadrant:
Upper outer : 50%
Upper inner: 15%
Lower outer: 11%
Lower inner: 6%
Areolar area: 18%