The Female Reproductive System

1
The Female Reproductive System

• How it works!

2
FEMALE REPRODUCTIVE SYSTEM

3
The Basic Function of the Female Reproductive
System

• Sexual Reproduction is the union of the female
  (ovum) and male (sperm) sex cells, to create a
  new individual. Each sex cell, also called
  Gametes, contain half the number of chromosomes
  that a normal body cell contains. When the
  nuclei of the two gametes unite (known as
  fertilization), the cells receive half of the
  genetic material from each parent cell.

4
ANATOMY Female Reproductive System

• The Ovaries are the primary female reproductive
  organ.
• The sex organs are called Gonads and
• It contains the female ova(egg) also called
  gametes.
• It secretes female sex hormones called estrogen
  and progesterone.
• The accessory structures or organs include
• the uterine or fallopian tubes, the uterus, and
  the vagina.

5
The Female Reproductive System
6
Anatomy The ovaries

• Each ovary is about the size of a large walnut
  and shaped like an almond. In young women the
  ovaries are about 1½ - 2 inches long, 1 inch wide
  and 1/3 of an inch thick. Once a woman reaches
  menopause, they shrink in size.
• The ovaries produce eggs or ova. All females are
  born with a lifetime supply of eggs. When all
  the eggs have been expelled a woman is said to be
  in menopause.
• The ovaries also produce hormones called
• estrogen and progesterone
• function of estrogens is development of female
  secondary sexual characteristics. These includes
  breasts, endometrium, and regulation of the
  menstrual cycle.
• prepare your body for conception and pregnancy
  and regulates the monthly menstrual cycle. It
  also plays a role in sexual desire.

7
Anatomy The fallopian Tubes (also called the
oviducts or uterine tubes)

• The fallopian tubes stretch from the uterus to
  the ovaries and measure about 8 to 13 cm in
  length.
• They range in width from about one inch at the
  end next to the ovary, to the diameter of a
  strand of thin spaghetti at the end connected to
  the uterus.
• Millions of tiny hair-like cilia, line the
  fimbria (which are finger-like projections) and
  the interior of the fallopian tubes. The cilia
  beat in waves, hundreds of times a second in
  order to catch the egg at ovulation and move it
  through the tube to the uterus.
• Fertilization typically occurs in the fallopian
  tube.

8
Anatomy The Uterus

• The uterus is a pear-shaped muscular organ.
• The fundus is the upper portion of the uterus
  where pregnancy generally occurs (or the
  developing fetus grows).
• The cervix is the lower portion of the uterus
  that connects with the vagina and serves as a
  sphincter to keep the uterus closed during
  pregnancy until it is time to deliver a baby.
• the uterus can expand considerably, during the
  reproductive process. It can grow10-20 times its
  normal size during pregnancy.

9
Location of the Uterus
10
Location Ovaries and the Fallopian/Uterine tubes

Figure 28.14a, b
11
Oogenesis

• Oogenesis is the creation of an ovum.
• When a female reaches puberty or sexual maturity
  (also called Menarche), the primary oocytes
  recommence their development. This means that the
  ovaries begin to grow and mature such that they
  begin to produce ova or eggs.
• The ova are usually produced one at a time and
  only once a month (or approx. every 28 days).

12
How is Ovulation Regulated ?
The HYPOTHALAMUS of the brain releases
Gonadotropin-releasing Hormone (GnRH), which
stimulates the release of Luteinizing Hormone
(LH) and Follicle Stimulating Hormone (FSH) from
the Anterior Pituitary gland of the brain. The
menstrual cycle begins with menstrual bleeding
(menstruation), which marks the first day of the
follicular phase. About this time, the FSH level
increases slightly, stimulating the development
of several ovarian follicles. Each follicle
contains an egg. As these follicles mature
(graafian follicles), they produce estrogen. The
follicles eventually rupture releasing an ova and
leaving an empty follicle called the corpus
luteum (the yellow body). As the FSH levels
decrease, the corpus luteum secretes estrogen and
progesterone that stimulates the building up of
the lining of the uterus in anticipation of
fertilization of an ova.
13
How is Ovulation Regulated ?Cont

• The moment that an ovum leaves the ovary is
  called ovulation. The egg erupts from the ovary
  on the 14th to 16th day of an approximate 28-day
  menstrual cycle. If the ova is not fertilized,
  the corpus luteum degenerates, and the egg is
  passed from the reproductive tract during
  menstrual bleeding or flow. At this point a new
  menstrual cycle begins, which is approx. two
  weeks after ovulation.
• If the egg is fertilized, the cells around the
  developing embryo begin to produce a hormone
  called Human Chorionic Gonadotropin (HcG). This
  hormone maintains the corpus luteum, which
  continues to produce progesterone, until the
  growing fetus can produce its own hormones.
  Pregnancy tests are based on detecting an
  increase in the HcG level.

14
When does ovulation occur? 

•  
• The timing of ovulation varies with the length of
  a woman's menstrual cycle.
• In the average 28 day menstrual cycle, the
  Leutinizing Hormone (LH) surge usually occurs
  between the cycle days 11-13 and ovulation
  follows about 36-48 hours later, on or close to
  cycle day 14.
• Women with shorter menstrual cycle lengths tend
  to ovulate earlier and women with longer cycle
  lengths tend to ovulate later than cycle day 14.
• Despite the variations in menstrual cycle length,
  the time from ovulation to the onset of the next
  menstrual period is usually constant (about 2
  weeks). This principle is the basis for the use
  of ovulation calendars that take into account an
  individual's shortest and longest cycle lengths.

15
Ovulation

16
FEMALE REPRODUCTIVE SYSTEM
? HORMONAL REGULATION OF OOGENSIS AND OVULATION
OVULATION
FOLLICULAR PHASE
LUTEAL PHASE
17
How fertilization occurs

• Fertilization occurs in the fallopian tubes (also
  called oviducts or uterine tubes) and takes place
  within hours of the sperm being released during
  sexual intercourse to a few (approx.3) days after
  the day of ovulation. Only one of the
  approximately 300 million sperm released into a
  female's vagina during intercourse can fertilize
  the single female egg cell. The successful sperm
  cell must enter the uterus and swim up the
  fallopian tube to meet the egg cell, where it
  passes through the thick coating surrounding the
  egg. The tip of the head of the sperm cell
  contains enzymes which break through the coating
  and aid the penetration of the sperm into the
  egg. Once the head of the sperm is inside the
  egg, the tail of the sperm falls off, and the
  perimeter of the egg thickens to prevent another
  sperm from entering.
• Sometimes two ova are released, and if
  fertilized, become what is called fraternal
  twins. These twins can be of the opposite sex.
  Identical twins are formed when one sperm
  fertilizes one egg, and as the egg cell divides
  and is forming many new cells, it splits and each
  part continues separately to undergo further
  division, each producing an embryo.

18
Picture How fertilization Occurs
19
Implantation

• Once the embryo (newly fertilized ovum/egg)
  begins to divide it will reach the blastocyst
  stage (approximately 5 to 6 days after
  fertilization) It then begins the process of
  implantation.
• The fertilized egg travels to the uterus and
  implantation takes place when the egg attaches or
  implants in the endometrium (or inner lining) of
  the uterus. At this point, the egg (or ova) and
  the developing placenta, begin to release Human
  Chorionic Gonadotropin (hCG) hormone. The
  presence of hCG will help facilitate the
  continued production of progesterone which is
  essential for a fertile, hospitable environment
  for the implanted egg until the third month of
  pregnancy in which the placenta (the outer sac
  that surrounds the developing embryo) begins to
  produce estrogen and progesterone (of which until
  this point, the corpus luteum was producing).
• http//www.pennmedicine.org/encyclopedia/em_Displa
  yAnimation.aspx?gcid000045ptid17

20
Pregnancy

• The embryo undergoes a 40 week (approx. 9 month)
  period of development or gestation in the uterus
  until the delivery of the fetus.
• During pregnancy (at approx. 6 months of
  gestation), the hormones from the ovaries and the
  placenta stimulate glandular tissues in the
  breasts to develop fully. After parturition
  (giving birth), hormones from the pituitary glad
  stimulate the production of milk (lactation).
• An embryo is called a fetus after the 2nd month
  of gestation or pregnancy.

21
Mammary Glands

• Are present in both sexes - normally only
  functional in females
• Developmentally they are derived from sweat
  glands
• They are contained within a rounded skin-covered
  breast anterior to the pectoral muscles of the
  thorax
• At the center of each breast is a ring of
  pigmented skin, called the areola - this
  surrounds a centrally protruding nipple.
• Internally - they consist of 15 to 25 lobes that
  radiate around the breast and open at the nipple
• Each lobe is composed of smaller lobules these
  contain alveoli that produce milk when a women is
  lactating during pregnancy.
• non-pregnant women - glandular structure is
  undeveloped thus the breast size is largely due
  to genes and the amount of fat deposits

22
The Mammary Glands
Figure 28.23a-c
23
Things to Remember!!!

• Gynecology is the study of the female
  reproductive system.
• Obstetrics is a specialty concerned with
  pregnancy and the delivery of a fetus.
• Sexual intercourse is also called Coitus,
  copulation, or pareunia.
• Puberty/menarche is the beginning of the fertile
  period and development of secondary sex
  characteristics
• Menopause is also called change of life and
  climacteric.
• The bartholin glands are two small glands on each
  side of the vaginal orifice (opening) that
  produce a mucous secretion to lubricate the
  vagina.
• To avoid a tear of the tissue between the anus
  and vagina (perineum) the obstetrician cuts this
  section during child birth called an episiotomy.
  
• The external genitalia of the female are
  collectively called the vulva
• The hymen is a mucous membrane that (normally)
  partially covers the entrance to the vagina.
• Afterbirth is the expelled placenta minute after
  the delivery of the fetus.

24
Pathology and Procedures of the Female
Reproductive System

• Endometriosis is when the endometrial tissue is
  abnormally located outside the uterus.
• Fibroids are benign tumors in the uterus.
• Pelvic inflammatory disease(PID) an infection of
  the female reproductive system and the leading
  causes are gonorrhea and chlamydial infections.
• Ectopic pregnancy implantation of the fertilized
  egg outside of the uterus
• Tubal ligation sterilization by blocking of the
  fallopian tubes by burning or cutting and tying
  them off.
• Abortion premature termination of a pregnancy
  before it is able to exist on its own.
• Cesarean section removal of the fetus by
  abdominal incision into the uterus.
• Pap Smear The physician inserts a vaginal
  speculum and wooden spatula along with a cotton
  swab to take secretions and cells from the vagina
  and cervix for microscopic examination.