Transcript REPRODUCTION

REPRODUCTION
Asexual Reproduction
Sexual Reproduction in Animal
Sexual Reproduction in Plant
Asexual Reproduction
Binary fission
Fragmentation
Budding
Spore formation
Vegetative propagation
Biotechnology
Binary fission
Bacterial growth
Fragmentation
Separated body part regeneration
Budding
Hydra
Spongy
Yeast
Spore formation
Fungi
Spore formed at
sporangium
Vegetative propagation
Stem tuber
Corm
Bulb
Artificial propagation
Biotechnology in asexual
reproduction in plant
Plant tissue grow in vitro with
nutrient and plant growth hormone
Animal Reproduction
Sexual reproduction
in Bacteria
Conjugation
Human reproduction
Male sex organ
Embryo develop
Female sex organ
Hormonal control
Fertilization
Birth control
Male sex organ
Male structure function
In the testis, sperm form in the seminiferous tubules,
but are stored in the epididymis where they mature.
They move through the vas deferens and mix with
secretions from the seminal vesicle and
bulbourethral gland to form the semen. They enter
the urethra at the base of the penis.
The urethra is the duct that can carry either urine or
semen. It originates at the bladder, meets the vas
deferens at the base of the penis, runs through the
penis, and opens to the outside at end of the penis.
Testis
Spermatogenesis
Sperm cell
mitochondrion
flagella
Nucleus in head
Female sex organ
Uterus and ovary
Ovary and oogenesis
oogenesis
Follicle and oogenesis
Follicle formation
The ovaries contain eggs stored in small pockets
called follicles. A follicle is an egg cell surrounded
by a layer of cells involved in egg maturation. These
ovarian follicles are formed in the woman's body
before birth.
Following puberty, every month, approximately 12
to 14 days after the first day of menstruation in a
"typical" monthly cycle, one of these follicles
reaches maturity and is released into the uterine tube
in a process called ovulation.
Oocyte
Butterfly Egg
Pathway of egg
Egg travel
At ovulation, a mature egg is released from one
of the ovaries into the body cavity. Before it has
a chance of getting lost it is captured by one of
the paired tubes called Fallopian tubes or
oviducts.
In the Fallopiian tube, the egg is slowly
propelled toward the uterus. If sperm are present
in the female reproductive system, one of the
sperm will penetrate the egg, normally while it
is still in the upper third of the Fallopian tube.
Fertilization
Sperm journey through female
reproductive system
It is possible to fertilize an egg with a sperm
ejaculated into the vagina up to 3 days prior to
ovulation.
Sperm will have reached the uterus through the
cervix. From there a few hundred of the original
hundreds of millions sperm will have traveled up
into the Fallopian tubes in search of an egg to
fertilize.
It is in the upper third of the Fallopian tubes that
fertilization most commonly occurs.
Position of fertilization
Fertilized egg
Implantation
Wrong implantation
Embryo development
Amniotic cavity
Chorionic cavity
Placenta
Hormonal control
Menstruation hormone
The first 12 days
For the first 12 days of the menstrual cycle,
estrogen has a negative effect on the production of
gonadotropins.
Following these 12 days the negative effect
changes to a positive effect on the production of
gonadotropic hormones.
This results in a small increase of follicle
stimulating hormone (FSH), but a large increase of
luteinizing hormone (LH.)
Ovulation
This sudden increase of LH causes the mature follicle
to release the egg. Following release of the ovum, the
ruptured ovarian follice develops into the corpus
luteum.
End of the cycle
The corpus luteum, in turn, secrete estrogen and
progesterone. These ovarian hormones are important
for the maintenance of the endometrial lining of the
uterus where the blastocyst implants itself.
Continued high levels of estrogen and progesterone
produce a negative feedback on the secretion of
gonadotropins by the anterior pituitary gland.
Effect of progesterone
Progesterone is required for maintenance of the
endometrial lining of the uterus where the
blastocyst is implanted. If the released egg is not
fertilized, the uterine lining is sloughed off,
completing the monthly uterine cycle. Following
the menstrual period, the ovarian and uterine
cycles begin anew, with the development of an
ovarian follicle, and the preparation of the uterus
for blastocyst implantation.
Progesterone is required for maintenance of the
endometrial lining of the uterus where the
blastocyst is implanted.
If the released egg is not fertilized, the corpus
luteum regress, and the production of progesterone
drops. The uterine lining is sloughed off,
completing the monthly uterine cycle. Following
the menstrual period, the ovarian and uterine cycles
begin anew, with the development of an ovarian
follicle, and the preparation of the uterus for
blastocyst implantation.
Thickness of uterus
Corpus luteum
Ovarian follicles following ovulation
After ovulation, changes continue to take place
in the ovaries. The remaining follicular cells
undergo structural and biochemical changes.
They develop into the corpus luteum.
While the ovarian follicles produced estrogen,
the corpus luteum produce both estrogen and
progesterone.
After ovulation, the ruptured ovarial follicle
becomes the corpus luteum. While the ovarian
follicles produced estrogen, the corpus luteum
produce both estrogen and progesterone.
Other hormone
Hormone
With the onset of puberty, the hypothalamus
increases the release of gonadotropin releasing
hormone (GnRH). This hormone is needed for
sexual maturity and normal reproduction.
GnRH stimulates the anterior pituitary gland to
release several hormones. Among them are the
gonadotropings "follicle stimulating hormone"
(FSH) and "lutenizing hormone" (LH.)
These gonadotropins act by stimulating the
production of sex hormones in the gonads (testes
and ovary.)
Position of hormone
production
Birth Control
Barrier Method
Hormonal Method
Intrauterine Devices
Traditional Method
Surgical Sterilization
Barrier Method
•Male Condom
•Female Condom
•Diaphragm
•Cervical cap
•Sponge
•Vaginal Spermicide
Male Condom.
The male condom is a sheath placed over the
erect penis before penetration, preventing
pregnancy by blocking the passage of sperm
Female condom.
The Reality Female Condom, approved by FDA in
April 1993, consists of a lubricated polyurethane
sheath shaped similarly to the male condom. The
closed end, which has a flexible ring, is inserted
into the vagina, while the open end remains
outside, partially covering the labia.
Available by prescription only and
sized by a health professional to
achieve a proper fit, the
diaphragm is a dome-shaped
rubber disk with a flexible rim that
works in two ways to prevent
pregnancy. It covers the cervix so
sperm can't reach the uterus, while
a spermicide cream or jelly
applied to the diaphragm before
insertion kills sperm.
The cervical cap is a soft rubber cup with a
round rim, sized by a health professional to
fit snugly around the cervix. It is available by
prescription only and, like the diaphragm, is
used with spermicide cream or jelly.
Sponge.
The sponge, a disk-shaped polyurethane device
containing the spermicide nonoxynol-9, is not
currently marketed but may be sold again in
the future. Inserted into the vagina to cover the
cervix, the sponge is attached to a woven
polyester loop for easier removal.
Vaginal Spermicides Alone
Vaginal spermicides are available in foam,
cream, jelly, film, suppository, or tablet forms.
All types contain a sperm-killing chemical.
Studies have not produced definitive data on
how well spermicides alone prevent pregnancy,
but according to the authors of Contraceptive
Technology, a leading resource for
contraceptive information, the failure rate for
typical users may be 26 percent per year.
Hormonal Method
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Oral contraceptive
Minipills
Emergency Contraceptive(Morning after)
Injectable progestins
Implantable progestins
Combined oral contraceptives.
Typically called "the pill," combined oral
contraceptives have been on the market for 40
years and are the most popular form of reversible
birth control in the United States. This form of
birth control suppresses ovulation (the monthly
release of an egg from the ovaries) by the combined
actions of the hormones estrogen and progestin.
Side effects of the pill, which often subside after a
few months' use, include nausea, headache, breast
tenderness, weight gain, irregular bleeding, and
depression.
Minipills.
Although taken daily like combined oral
contraceptives, minipills contain only the hormone
progestin and no estrogen. They work by reducing
and thickening cervical mucus to prevent sperm
from reaching the egg. They also keep the uterine
lining from thickening, which prevents a fertilized
egg from implanting in the uterus. These pills are
slightly less effective than combined oral
contraceptives.
Side effects of minipills include menstrual cycle
changes, weight gain, and breast tenderness.
Emergency Contraceptive
("Morning After Pill")
Two emergency contraceptive pill products
have been approved by FDA for use in
preventing pregnancy after intercourse when
standard contraceptives have failed or when no
contraceptives were used at all. One product
contains the hormones progestin and estrogen;
the other contains just progestin.
Side effects include nausea and vomiting, both
of which were reported less frequently in
women taking the progestin-only pills.
Injectable progestins
is injected by a health professional into the
buttocks or arm muscle every three months.
Depo-Provera prevents pregnancy in three ways:
It inhibits ovulation, changes the cervical mucus
to help prevent sperm from reaching the egg,
and changes the uterine lining to prevent the
fertilized egg from implanting in the uterus.
Implantable progestins
Made up of matchstick-sized rubber rods, this
contraceptive is surgically implanted under the
skin of the upper arm, where it steadily releases
the contraceptive steroid levonorgestrel.
The six-rod Norplant provides protection for up
to five years
Intrauterine Devices
An IUD is a mechanical device inserted into the uterus by a
health-care professional. The Paragard IUD can remain in
place for 10 years, while the Progestasert IUD must be
replaced every year.
It's not entirely clear how IUDs prevent pregnancy. They seem
to prevent sperm and eggs from meeting by either
immobilizing the sperm on their way to the fallopian tubes or
changing the uterine lining so the fertilized egg cannot implant
in it.
Side effects can include pelvic inflammatory disease (an
infection of a woman's reproductive organs), ectopic
pregnancy (in which a fertilized egg implants in the fallopian
tube instead of the uterus), perforation of the uterus, heavierthan-normal bleeding, and cramps. Complications occur most
often during and immediately after insertion.
Traditional Method
•Fertility awareness
•Withdrawal
Fertility awareness.
Also known as natural family planning or
periodic abstinence, fertility awareness
entails not having sexual intercourse or using
a barrier method of birth control on the days
of a woman's menstrual cycle when she is
more likely to become pregnant.
Withdrawal.
In this method, also called coitus
interruptus, the man withdraws his penis
from the vagina before ejaculation.
Fertilization is prevented if the sperm don't
enter the vagina.
Surgical Sterilization
•Vasectomy
•Tubal ligation
Vasectomy
This procedure, called a vasectomy, involves sealing,
tying or cutting a man's vas deferens, which
otherwise would carry the sperm from the testicle
to the penis.
Tubal Ligation
Female sterilization blocks the fallopian tubes so
the egg can't travel to the uterus. Sterilization is
done by various surgical techniques, usually under
general anesthesia.