THE FEMALE REPRODUCTIVE SYSTEM
ANATOMY AND PHYSIOLOGY | Dr. Carolina Jerez, M.D. | MT1A | A.C.
ANATOMY
MATURATION
Internal Female Reproductive System
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Ovaries are near the embryonated portion of the fallopian
tubes so when the ovum is released, it can go directly
into the fallopian tube.
Meiotic Events
o Occurs in the ovaries during development
o Maturation of follicles
o Mitosis:
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Oogonium - stem cell
o Maturation from puberty up to menopausal
o Only 400 out of 800,000 follicles will go through
maturation/will be ovulated during a women’s reproductive
lifetime.
o The prime of the female is limited only to the number of
follicles that can be released due to the finite number of
eggs which can mature during her lifetime.
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Walls of uterus:
1. Endometrium - shed during menstruation
2. Myometrium
3. Perimetrium
Uterosacral ligament - supports the uterus
Suspensory ligament of ovary - attached to the ovaries
Follicle Development in Ovary
o Primordial follicle
o Primary follicle
o Growing follicles
o Ovulation normally occurs every month when puberty
occurs.
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FEMALE REPRODUCTIVE SYSTEM
Mitosis and Meiosis
MENSTRUAL CYCLE
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Before birth: Oogonium undergoes mitosis, arrested in
the prophase I, which is the primary oocyte
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After puberty: Meiosis continues, producing polar body,
secondary oocyte that is arrested in metaphase II, then
ovulation. If there is fertilization, it will develop into a
zygote.
Regulation of Processes
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Activities are governed by secretions coming from the
hypothalamus, the gonadotropin releasing hormone
(GRH), which stimulates the pituitary to release the follicle
stimulating hormone (FSH) and luteinizing hormone (LH).
This, in turn, affects the granulosa cells and thecal cells.
Granulosa cells - secretes estrogen and progesterone
Thecal cells - secretes androgen
During the late follicular phase or ovulation, the GRH
affects the pituitary, as well as the ovaries.
Granulosa cells and thecal cells are found in the ovaries.
Inhibin - inhibitory to FSH
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OVARIAN CYCLE
The ovarian cycle starts with the development of the follicle
called the FOLLICULAR PHASE
à This is associated with the rise in FSH.
à In a 28 day cycle, ovulation occurs in the middle of the
cycle (usually the 14th day) ushered by a rise in
estrogen, stimulating an LH surge—a positive
feedback effect.
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FEMALE REPRODUCTIVE SYSTEM
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The second half of the cycle is the LUTEAL PHASE
à Final phase prior to menstruation if there is no
fertilization occurring
à The corpus luteum persists which is the progesterone
source.
à During
pregnancy,
fertilization
occurs.
The
progesterone helps with the progression of pregnancy.
à There will be a decline in FSH and LH.
à A decline in estrogen and progesterone causes the
sloughing off the endometrium—Menstruation
ENDOMETRIAL CYCLE
The endometrial cycle consist of the
o MENSTRUATION - sloughing of endometrium.
Endometrium is developed in preparation to
possible pregnancy. If there is no fertilization, thus
no pregnancy, menstrual bleeding will occurs due
to the decrease in the amount of estrogen and
progesterone.
o PROLIFERATIVE PHASE - development of the
endometrium incase fertilization occurs; Increase in
the thickness and vascularity of endometrium.
o SECRETORY PHASE - after ovulation; there is an
increase in the secretion in the endometrium;
increased number of glands and blood supply until
the next menstruation (if unfertilized).
Autocrine Control of Lactation
Influence of Local Factors Acting on the Breasts
o It is not just the level of maternal hormones, but the
efficiency of milk removal that governs the volume product
in each breast
o More sucking of the baby = more milk production of the
mother
o A protein factor called feedback inhibitor of lactation
(FIL) is secreted with other milk components into the
alveolar lumen
o FIL, insensitive to prolactin à U milk production
Control of breastmilk production within the breast
Stages of Lactogenesis
BREAST
à 1st stage: Endocrine Control; before birth
à 2nd stage: At birth
à 3rd stage: Autocrine (local) Control
- 30 to 40 hours after giving birth. Prolactin
decreases = decrease in the amount milk. The
suckling will become the stimulus for continuous
milk production.
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The breast is primarily made up of fat tissues
Attached to the pectoralis major muscle
Areola - the brownish portion of the breast
Control of Milk Secretion and Production
Milk Production Reflex:
o Prolactin is a key lactogenic hormone
stimulating initial alveolar milk production
Milk Ejection Reflex:
o Oxytocin contracts the myoepithelial cells
forcing milk from the alveoli into the ducts and
sinuses where it is removed by the infant due to
sucking.
o After the baby is born
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FEMALE REPRODUCTIVE SYSTEM
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Physiology of Lactation
Lactation and milk production goes into 3 stages:
1. Lactogenesis I
2. Lactogenesis Il
3. Lactogenesis Ill
Lactogenesis I and II à milk supply is hormonally driven
endocrine control system.
Lactogenesis III à switch to the autocrine (or local)
control system
After Lactogenesis II, there is a switch to the autocrine (or
local) control system (Lactogenesis Ill)
Maintenance stage of milk production
o Milk removal is the primary control mechanism for supply.
o Under normal circumstances, the breasts will continue to
make milk indefinitely as long as milk removal continues.
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THE MALE REPRODUCTIVE SYSTEM
ANATOMY AND PHYSIOLOGY | Dr. Carolina Jerez, M.D. | MT1A | A.C.
ANATOMY
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Superficial inguinal ring - common site of hernia in males
Ejaculatory Duct
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Testis
There are also different glands which assist the sperm
during release. There will be an increase in the amount of
fluid which is contributed by the secretions coming from the
prostate gland, bulbourethral glands, and seminal vesicles.
They add into the secretion coming from the testis
Testicle
A diagram of the major components of an
adult human testis:
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Tunica albuginea - covers the lobules
Epididymis - where final maturation of sperm occurs
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Terminologies
Spermatogenesis - process and events where the
spermatogonia gives rise to spermatocytes
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Spermiogenesis - the spermatids differentiate to a
mature spermatozoon
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Spermiation - spermatozoa are released from the
seminiferous tubules to migrate into the epididymis
where they fully differentiate (maturation occurs) to
motile spermatozoa.
Anatomy
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Tunica albuginea
Septula testis
Lobulus testis
Mediastinum testis
Tubuli seminiferi contortI
Tubuli seminiferi recti
Rete testis
Ductuli efferentes testis
a. Head of epididymis
b. Body of epididymis
c. Tail of epididymis
10. Vas deferens
11. a. Tunica vaginalis
(parietal lamina)
b. Tunica vaginalis
(visceral lamina)
12. Cavity of tunica vaginalis
a.
b.
c.
Glands and Secretions
Prostate - Located below the bladder and the primary
function is to produce fluid that nourishes and transports
sperm. This helps in maturation of sperms.
Bulbourethral gland - Secretions will neutralize acidity of
the vagina and helps lubrication during intercourse. Also
known as Cowers gland.
o The vaginal canal is acidic due to acidic
secretions. Acidity is important to prevent
infections.
o Neutralizing the acidity will prevent the sperm
from dying.
Seminal vesicles - Secretes fluid for semen coagulation,
sperm motility, stability of sperm chromatin, and
suppression of immune activity in the female reproductive
system.
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MALE REPRODUCTIVE SYSTEM
Sperm Formation
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Luteinizing Hormone (LH) - affects the Leydig cells.
Leydig cells are stimulated for the secretion of
testosterone, which affects the Sertoli cells.
Spermatogenesis
The process of spermatogenesis takes place in the
seminiferous tubules. But the final maturation occurs in
the epididymis
Microtubules and flagellum allow the sperm to swim from
the vagina into the cervix
After fertilization, the fertilized ovum will be implanted in
the endometrium
Maturation
Regulation of Process
Normal Values
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What medical technologists must know in fertility
workups:
o Sperm count
o Motility
o Morphology
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Activities are controlled by the hypothalamus. From the
hypothalamus, GRH affects the anterior pituitary which
secretes FSH and LH.
Follicle-stimulating Hormone (FSH) - necessary for the
secretion of androgen-binding protein (ABP). It affects
the Sertoli cells.
Inhibin - inhibitory to FSH
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MALE REPRODUCTIVE SYSTEM
Male Reproductive Tract
Pathway of Sperm
1. Epididymis
2. Testicle
3. Vas deferens
4. Seminal Vesicle
5. Prostatic urethra
6. Ejaculatory duct
7. Urethra
Accessory Reproductive Glands
a. Seminal vesicle
b. Prostate
c. Bulbourethral gland
Penis
a.
b.
c.
d.
e.
Body of penis
Corpus cavernosum
Corpus spongiosum
Urethra
Glans penis
Pathway of Sperm
1. Produced in the testes
2. Stored in the Epididymis
3. Travels through the Vas Deferens
4. Combines with fluid from the Seminal Vesicles
5. Combines with fluid from the Prostate gland
6. Combines with fluid from the Cowper's gland
7. Now called semen, travels through urethra in the penis
8. Leaves the body through the opening in the penis
during ejaculation
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HUMAN REPRODUCTION
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ANATOMY AND PHYSIOLOGY | Dr. Carolina Jerez , M.D. | MT1A | A.C.
HUMAN REPRODUCTION
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By the union of seminal vesicular ducts and vas deferens,
Can be defined as the production of one or more
a short canal is formed, it is called as Ejaculatory Duct
offspring by an existing organism.
which further unites with the ureter to form a common
passage the urethra—which opens to outside of the body
This capacity has enabled the origin and propagation of
through the penis.
various forms of life on Earth.
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Seminiferous tubule is lined on its inside by two types of
Reproduction involving two distinct sexes (male and
cells called:
female) is the characteristic feature of all forms of life and
1. Male germ cells undergo meiotic division finally
has played a prominent role in the origin of species and
leading to sperm formation
diversity of life by bringing together many characters
2. Sertoli cells provide nutrition for the germ cells
The primary function of sex is to produce gametes, and
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Outside of Seminiferous tubules called interstitial spaces,
the primary sex characters are the gonads and testes
contain small blood vessels and interstitial cells or
in male and ovaries in females
Leydig cells. Leydig cells synthesize and secrete
Fertilization - is internal and fetus develops inside the
testicular
hormones
called
androgens.
Other
uterus of the mother (viviparus)
immunologically competent cells are also present
Female reproductive system is extremely modified to
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Two glands: Prostate and Bulbourethral (Cowper’s)
enable internal fertilization and maintenance of
glands open into the urethra
pregnancy
o They produce mucus that lubricates the urethra
Sperm formation continues even in old men, but
to facilitate ejaculation of sperm during
formation of ovary ceases in volume around the age of
copulation
50 years.
o Secretions of these glands constitute the
seminal plasma, which is rich in fructose,
MALE REPRODUCTIVE SYSTEM
calcium, and certain enzymes
The male reproductive system is located in the pelvis
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External genital organ in male is penis through which
region.
urethra runs. It is an erectile organ and helps in sperm
It includes a pair of testes, along with accessory duct
deposition in the vagina during copulation.
glands, and the external genitalia.
It consists of a pair of testes lodged in an integumentary
pouch—the scrotum. Initially they are abdominal,
however as the development proceeds, they descend
down into the scrotum
It has been proved that this adaptation enables
regulation of internal temperature of the testes higher
than body temperature which is essential for their normal
functioning.
In adults, each testis is oval in shape, with a length of
about 4 to 5cm and a width about 2 to 3cm.
The testis is covered by a dense covering, each testis
has about 250 compartments called testicular lobules
o Each lobule contains one to three highly coiled
somniferous tubule in which sperms are
produced
Many such seminiferous tubules after exit again from a
complex network of tubular system known as ReteTestis
Small ducts from rete-testis again unite to form a large
convoluted duct called as epididymis, in which sperms
are stored. Epididymis continues into vas deferens which
carry sperms away from the testis.
Vas deferens, after curving back over lower abdominal
area, enlarge to form Ampulla, in which opens a coiled
tube with sacculated walls; this is the Seminal Vesicle.
o Seminal vesicle - It is supposed to perform
nutritive function by providing fructose and other
nutrients to maintain vitality of sperms.
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FERTILIZATION
The union of the male and female gamete
There is only one sperm that can fertilize an ovum.
Once the sperm has penetrated the ovum, no other
sperm is allowed to penetrate the egg.
Fertilization occurs in the ampullary portion of the
fallopian tube.
Fertilized egg is brought into the uterus for implantation.
During the luteal phase that the implantation occurs as it
is the time where there is an increased in production of
progesterone coming from the corpus luteum.
Progesterone at this time will prevent uterine contraction,
helping the maintenance of the pregnancy.
PREGNANCY
Ectopic pregnancy - when the fertilized egg is implanted
anywhere outside/other than the uterus.
40 weeks gestation
o 1st week - there is a rise in human chorionic
gonadotropin hormone (hCG) which is detected by
pregnancy tests. However, a positive pregnancy
test does not always tell if a person is really
pregnant. Some health conditions that cause a rise
in hCG can lead to a positive test result. (ex.
hydatidiform mole).
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HUMAN REPRODUCTION
from the posterior pituitary. It strengthens uterine
contraction so that birth can take place.
Trigger of Parturition
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Unknown, but current theory suggests signal comes from
fetus.
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Fetal placenta
- CRH à fetal ACTH à DHEA (dehydroepiandrosterone)
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DHEA à estrogens
- Enters maternal blood stream
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Estrogen à parturition
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PARTURITION
Parturition = birth
Pregnancy lasts 40 weeks
Lactation - is milk production in mammary glands
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Prolactin - stimulates
milk synthesis from
alveoli
Oxytocin - stimulates
the milk ejection reflex
Events
Colostrum - watery milk that is produced the first few days after
birth. It has a lot of proteins and antibodies.
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At the end of pregnancy: the cervix ripens—the cervix
becomes softer and flexible. There will be an enzymatic
breakdown of tissues in the area (connective tissues and
collagen fibers)
The cervix starts to dilate at the beginning of labor.
Contractions begin
The baby’s head wedges the cervix open. A baby is born
head first.
After birth = expulsion of placenta
Labor and Parturition
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The pressure of the fetus up against the cervix causes the
positive feedback loop that causes the release of oxytocin
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