Reproductive Health

PARTURITION
The average duration of human pregnancy is about nine months. This is called gastration period. At
the end of the pregnancy, Vigorus contraction of the uterus causes delivery of foetus. This process of
expulsion of the foetus is called parturition. The signals for expulsion of the foetus originated from the
fully developed foetus and the placenta and induced by a complex neuro-endocrine mechanism.
Which induces mild uterine contraction called foetal ejection reflex. This triggers release of oxytocin
from mother’s pituitary. Oxytocin acts on the uterine muscle and causes stronger contraction to expel
the baby out of uterus through birth canal.
The mammary glands start producing milk towards the end of pregnancy by the process of called
lactation. The milk produced during the initial few days of lactation is called colostrums, which
contains several antibodies essential to development resistance for the new born babies.


CHAPTER: 4 REPRODUCTIVE HEALTH.
Reproductive health means a total well being in all aspects of reproduction i.e. physical emotional
behavioural and social.
There is a little knowledge of personal hygiene and hygiene of reproductive organs. This causes
sexually transmitted diseases. Early marriages lead to high maternal and infant mortality rates. Due to
lack of awareness there has been a rapid increase in population size. People encourage beliefs in
myths and misconceptions about sex-related issues. Family planning programmes were initiated as
early as 1951. Reproductive and child health care programmes were launched in 1997 for creating
awareness among people about various reproduction related aspects. Providing facilities and support
for building up a reproductively healthy society. With the help of audio-visual and print media both
government and non-government agencies are engaged in creating awareness among people about
reproduction-related aspects. Encouraging sex education in schools to give the right information to
young minds and save them from myths and misconceptions about sex-related aspects. Proper
information about reproductive organs, adolescence and related changes, safe and hygienic sexual
practices and sexually transmitted diseases should be given. Educating people about available birth
control options, care for pregnant mothers, post natal care of the mother and child, importance of
breast feeding equal opportunities for the male and female child. Statutory ban on amniocentesis for
sex determination to legally check increasing female foeticides

Population explosion
The tremendous increase in size and growth rate of population is called population explosion the
world population is about 2 billion in 1900 and it was 6 billion in 2000. Population of India at the time
of independence was about 350 million and it crossed one billion in 2000. Reasons for the high
population growth are rapid decline in death rate, decline in maternal mortality rate, and decline in
infant mortality rate and increase in number of people in reproductive age. According to 2001 census
report, the population growth rate was about 1.7 per cent, i.e., 17/1000/year in India.
Birth control: The most important step to control population growth is to motivate smaller families by
using various contraceptive methods.
An ideal contraceptive should be
a. User-friendly
b. Easily available
c. Effective and reversible with no or least side effects
d. Non-interfering with the sexual derive desire and or the sexual act of the user.
Methods of birth control
The contraceptive methods are divided into following categories;
I. Natural contraception: This is the natural method of birth control ;which involves the rhythm
method and coitus interrupts
a. Rhythm method: In this method sexual intercourse should be avoided a few days prior to and a
few days after ovulation to prevent fertilization of the ovum. Intercourse should be avoided 5 days
prior and 5 days after ovulation. The period of 11 days is known as the danger period when
fertilization is likely to take place. 5
th
to 9
th
day and 21
th
to 28
th
day is called safe period when
fertilization is not likely to take place.
b. Coitus interrupts; This practice should be made by men. It involves removal of the penis from
the vagina before ejaculation.
II. Mechanical contraception: This is the method where using mechanical devices to prevent control
of birth.
a. Condom: This is used by men. Condom is a non-porous. Elastic, tight fitting sheath of rubber.
The ejected semen is trapped in the condom and thus the entry of sperms into the vagina is
prevented.
b. Diaphragm: This is used by women. It is a dome shaped device. It is inserted into the vagina
and positioned over the cervix before intercourse.
c. Intrauterine device (IUD): these devices are used by women. The device is in the form of a
small object made up of plastic copper or stainless steel. It is in the form of a loop, coil, T or 7-
shaped. The IUD is provided with strings which are useful to check and confirm its position by
experienced gynecologist. It prevents implantation. It is a reliable method of birth control.
III. Chemical contraception: Prevention of conception by using chemicals is called chemical
contraception. It involves the use of oral pill and vaginal spermicides.
a. Oral pill: oral contraceptive is hormonal preparations in the form of pills. They are either
progestogens or progestogen-estrogen combination. They alter ovulation and implantation and also
modify the quality of cervical mucus to prevent entry of sperms, which inhibit the release of FSH and
LH form the pituitary. Saheli is an example of oral contraceptive, which contains a non-steroidal
principle called ‘centchroman’ it is once a week pill.
b. Vaginal spermicides: sperm-killing chemicals in the form of foams, creams, jellies and
suppositories are introduced into the vagina before intercourse to kill the sperms.


IV. Terminal methods: surgical sterilization is the most effective and reliable method of birth control.
Both men and women can undergo sterilization.







c. Vasectomy: This method of male sterilization. It involves surgical removal of a small portion of each
vas deferens. An incision is made in the scrotum on each side, the vas deference is located and each
one is tied in two places. Then the portion between the two ties is cutoff. In this; method production of
sperms continues in the testes but they cannot reach the urethra.
d. Tubectomy: This is a method of female sterilization. It involves surgical removal of a small portion of
each uterine tube. A small incision is made into the abdominal cavity and the uterine tubes are
squeezed to form a small loop called knuckle. A suture is tied tightly at the base of the knuckle and
then the knuckle is cut. Therefore, the ovum is prevented from passing into the uterus and the sperms
cannot reach the ovum.
e. Laparoscopic technique: This is a method of female sterilization. After giving a local anesthesia, a
harmless gas is introduced into the abdomen cavity and pushes the intestines away from the pelvic
cavity so that the uterine tubes could be easily seen. A small incision made at the lower rim of the
umbilicus to insert a laparoscope to locate, cut and close the uterine tubes.


I. Medical termination of pregnancy (MTP)
Terminal of pregnancy is called abortion. Medical termination of undesired pregnancy y is a method
of birth control. MTP is essential where pregnancy could be harm full to the mother or the foetus or
both.
f. Removal of the testes is called castration.
g. Removal of the ovary is called oophorectomy.
h. Removal of the uterus is called hysterectomy.
Sexually transmitted diseases
Diseases or infections which are transmitted through sexual intercourse are collectively called as
sexually transmitted diseases or venereal diseases. Gonorrhea, syphilis, genital herpes,
chlamydiasis, genital warts, trichomoniasis, and hepatitis-B and AIDS. Among these HIV infection is
most dangerous and medicine has not yet been discovered. These infectious diseases transmitted by
sharing of infection needles, surgical instruments etc., with infected person, transfusion of blood or
from an infected mother to the foetus too. Except for hepatitis-B, genital herpes and HIV infections,
other diseases are completely curable if detected early and treated properly. Early symptoms of most
of these are minor and include itching, fluid discharge, slight pain swellings, etc., in the genital region.
Infected females may often be asymptomatic and hence, may remain undetected for long. Absence
or less significant symptoms in the early stages of infection and the social stigma attached to the
STD’s deter the infected persons from going for timely detection and proper treatment. This could
lead to complications later. Which include pelvic inflammatory disease abortions, still births, ectopic
pregnancies infertility or even cancer of the reproductive tract. STD’s are a major threat to a healthy
society. Therefore, prevention or early detection and cure of these diseases are given prime
consideration under the reproductive health-care programmes.
By the following simple principles, STD’s can be prevented
a. Avoid sex with unknown partners/multiple partners.
b. Always use condoms during intercourse.
c. Contact a qualified doctor for any doubt in early stage of infections.
Infertility
It is the inability to produce children in spite of unprotected sexual cohabitation. The reasons of
infertility could be physical, congenital diseases, drugs, immunological or even psychological.
Specialized health-care units called infertility clinics could help in diagnosis and corrective treatment
of some of these disorders. The infertile couples could be assisted to have children through certain
special techniques called assisted reproductive technologies which are as follows.
a. Test tube baby programme: in this method, ova from the wife or a donor female and the sperms
from the husband laboratory; it is called in vitro fertilization (IVF). The zygote or early embryo is
transferred into the uterus or fallopian tube for further development; this process is called embryo
transfer (ET) and can be done in the following two ways.
 The zygote or embryo up to eight blastomeres is transferred into the fallopian tube, it is called zygote
intra fallopian transfer (ZIFT)
 Embryos with more than eight blastomeres are transferred into the uterus; it is called intra uterine
transfer (IUT)
b. Gamete intra fallopian transfer (GIFT): this method involves the transfer of an ovum collected from
a donor female into another female, who cannot produce ova, but can provide suitable conditions for
fertilization and further development of the foetus up to parturition.
c. Intra cytoplasmic sperm injection (ICSI); in this method, the sperm is directly injected into the
ovum to form an embryo in the laboratory and then embryo transfer is carried out.
d. Artificial insemination: In this method, the semen collected from the husband or a healthy donor, is
artificially introduced in to the vagina or into the uterus it is called intra uterine insemination (IUI). This
method is used in cases where infertility is due to the inability of the male partner to inseminate the
female or due to very low sperm counts in the ejaculates.
Amniocentesis: it is a prenatal diagnostic technique, in which a sample of amniotic fluid from the
womb or a pregnant woman is taken during the early stages of foetal development and the cells are
cultured and analyzed. By this method the chromosomal abnormalities, the sex of the foetus and
developmental disorders could be detected for treatment. Since it is misused for destroying the
normal female fetuses, there is a statutory ban on this technique, to legally check female foeticides.






CHAPTER: EVOLUTIONS
Origin of life:
The origin of life is considered a unique event in the history of universe. The universe is about twenty
billion years old. It includes huge clusters of galaxies, which contain stars and clouds of gas and dust.
The big bang theory explains that the universe arose from a huge explosion of a very large entity. As
a universe expanded, the temperature decreased; hydrogen and helium were formed sometime later.
The gases condensed under gravitation and formed the galaxies of the present day universe.
Earth was supposed to have been formed about 4.5 billion years before, in the solar system of the
milky-way galaxy. Water vapour, methane ammonia and carbon dioxide were released from the
molten mass. The UV rays from the sun broke up water into hydrogen and oxygen. The lighter
hydrogen gas escaped from the surface, while oxygen combined with other compounds to form
water, carbon dioxide, etc. as the water vapour cooled, the water fell as rain and filted all the
depressions to form oceans and other water bodies. From the oxygen, ozone layer was also formed.
Life started appearing about 500 million years after the formation of earth.
Theories of origin of life
Different theories were given to explain the origin of life. Life appeared 500 million years after
formation of earth. Following are the theories to explain the origin of life on earth.
1. Theory of special creation: According to this theory, god created life by his divine act of creation.
2. Theory of panspermia/cosmozoic theory: according to early Greek thinkers, units of life called spores
or panspermia came from outer space and developed into living forms.
3. Theory of spontaneous generation: According to this theory, life originated from decaying and rotting
matter like straw and mud.
4. Theory of chemical evolution or oparin-Haldane theory: this theory was given by Oparin-Haldane and
stated that life originated fr5om pre-existing non-living organic molecules. The conditions on earth
favouring chemical evolution were high temperature, volcanic activities, reducing atmosphere
containing CH
4
, NH
3
etc.
Experimental evidence of chemical evolution/miller’s experiment
Experiment was performed by S.L.Miller and H.C Urey in 1953. They created electric discharge in a
closed flask containing CH
4
, NH
3
, H
2
and water vapour at 800
0
C. They observed formation of amino
acids, sugars, nitrogen bases, pigment and fats. Analysis of meteorite content also revealed similar
compounds indicating that similar processes are occurring elsewhere in space. With this limited
evidence, the first part of the conjectures story. It provides experimental evidence for the theory of
chemical origin. It showed that the first non-cellular form of life was created about 3 billion years ago.







Evidences for evolution
1. Paleontological evidences: The study of fossil is called paleontology. Fossils are the remains or
impressions of past whole organism or part of it is preserved in sedimentary rocks or other media.
Different aged rock sediments in earth’s indicate the presence of fossils of different life forms which
died during the sediment formation. A variety of fossils ranging from the modern organisms to extinct
organisms can be observed. By studying the different sedimentary layers, the geological time period
in which the organism existed can be predicted.
2. Comparative anatomical and morphological evidences: the phylogenetic history can be revealed
by comparative study of external and internal structure.
Homologous organs: These are the organs show similarity in the basic structure and embryonic
development but perform different functions. Homology of organ of different organisms indicates their
common ancestry. For example, the fore-limbs of whale, bat, man and cheetah have similar
anatomical structures but due to the different needs, some structures developed differently for
different functions. This is called divergent evolution.
.






Homologous organs analogous organs

Analogous organs: These are the organs perform same functions but structurally they are different
from one another. For example, wings of butterfly and birds. Anatomically they are dissimilar but
functionally they are same. This is called convergent evolution.

3. Bio-chemical evidence: The similarities in the proteins and genes performing a common given
function among diverse organisms give clues to common ancestry. The metabolic processes in
organisms are also similar with same new materials and end products.
4. Bio-geographical evidence: species restricted to a region develop unique features. Also species
present in widely separated regions show similarity of ancestry.
Adaptive radiation








It is an evolutionary process in which different species starting from a common point in a geographical
are radiate to other geographical areas. Darwin observed many varieties of finches (small black birds)
in the Galapagos Island and all the varieties, he conjectured, evolved on the island itself. But from the
original seed-eating features, many other forms with altered beaks arose, enabling them to become
insectivorous and vegetarian finches. This process of evolution of different species in a given
geographical area starting from a point and literally radiating to other areas of geography is called
adaptive radiation.
Another example is Australian marsupials. A number of marsupials, each different from the other
evolved from an ancestral stock, but all within the Australian continent. When more than one adaptive
radiation appeared to have occurred in an isolated geographical area but representing different
habitats. One can call this convergent evolution. For example (placental wolf and Tasmanian wolf-
marsupial; flying squirrel and flying phalanger-marsupial, etc.)
Theories of biological evolutions
a. Lamarck’s theory: according to Lamarck, evolution of life forms occurred due to use and disuse of
organs. As of his view, giraffes initially did not have long necks. But to access leaves on tall trees,
they had to adapt by elongating their necks. By passing this acquired character to succeeding
generation, they acquired long necks. This theory is no more accepted due to wrong concepts.
b. Darwin’s theory: Charles Darwin based on his observations during his trips to Galapagos Island, he
concluded following aspects.
 There has been gradual evolution of life forms with new forms arising at different periods of history.
 Any population has built in variations in characteristics which adapt it better to environment.
 The individuals to survive better in natural conditions only over-come challenges from nature (survival
for the fittest).
 Those populations which are better fit in an environment will be selected by nature (natural selection).
 Natural selection is based on following factual observations
1. Limited natural resources.
2. Stable population size except seasonal fluctuations.
3. Varying characteristics of members of populations.
4. Most of the variations are inherited.
Industrial Melanism:
In England before industrialization, white-winged moths were more in number than dark-winged
moths. But after industrialization dark-winged moths becomes more in number than white-winged
moths. This is because during industrialization, white lichens died, due to dust and coal particles. In
the pre-industrial period, the white winged moths could survive better as the trees were covered with
almost white coloured lichens. As a result white-winged moths could be easily picked by predators
from the dark background and dark-winged moths survived. But in rural areas where industrial
revolution did not occur, the melanic forms did not survive and their count was low. It shows that in a
mixed population, individuals that are better adapted survive and reproduces in large numbers and
increase their population size and no variant was completely wiped out.
c. Mutation theory: This is put forward by Hugo de Vries based on his work on evening primrose.
According to him evolution is caused by sudden large differences in the population. Mutation and not
the minor variations as per Darwin. He believed that mutation brings formation of new species.
Formation of new species from mutation is called saltation. Mutations are random and directionless
in contrast to small directional variations as per Darwin.
Hardy-Weinberg principle: this principle states that allelic frequencies in a population are stable and
remains constant from generation to generation. I.e. gene pool is constant. This is called genetic
equilibrium or hardy-weinberg equilibrium. It can be expressed as p
2
+2pq+q
2
=1 where p and q are
frequencies of different alleles. Disturbances in genetic equilibrium results in evolution.
The following are the factors affecting hardy-Weinberg equilibrium.
1. Gene migration or gene flow: when individuals migrate to another plac4e or population new genes or
alleles are added to new population and are lost form old population, in turn changing the
frequencies. When gene migration occurs many times, it is called gene flow.
2. Genetic drift: A change occurring in frequencies by chance is called genetic drift. Sometimes, due to
changes in allele frequency in new population, some form a different species. This effect is called
founder effect and the original drifted population is called founder.
3. Mutation: advantageous mutations lead to new phenotypes and over few generations, result in
speciation.
4. Genetic recombination: during gametogenesis, variations due to recombination result in new
phenotypes.
5. Natural selection: heritable variations that enable survival of the fittest will leave greater number of
progeny. Natural selection can have following three effects.
 Stabilization: Large number of individuals acquires mean character value.
 Directional change: Large number of individuals acquires value other than mean character value.
 Disruption: Large number of individuals acquires peripheral character value at both ends of the
distribution curve.
Evolution of Plants: plants invaded land before animals. Bryophytes originated earlier than the
vascular plants like pteridophytes and gymnosperms. The first vascular developed in Silurian period.
Seed weeds and few plants existed around 320 million years back.
Evolution of Animals: around 500 million years back invertebrates originated and were active.
Around 350 million years back jawless fish and amphibious fish with stout and strong fins originated.
Lobefins were the first amphibians and ancestors of modern-day frogs. Around 200 million years back
reptiles dominated the earth. The land reptiles were dinosaurs, of which tyrannosaurus rex was
biggest. Dinosaurs suddenly disappeared around 65 million years back. The first mammals that
evolved in Jurassic period were like shrews (mouse like animals)
Evolution of man
The common ancestor of apes and man is a primate Dryopithecus that lived 15 million years ago. At
the same time, another genus Ramapithecus also existed. Both were hairy and walked like gorillas
and chimpanzees. Dryopithecus was more ape-like; Ramapithecus was more man-like and is the
forerunner of hominid evolution.
1. Australopithecines: they probably lived 2 million years back, in the east African grasslands. They had
a brain capacity of 450cc-600cc. they hunted with stone weapons but essentially ate fruits.
2. Homo habilis: This is called the first human-like being, the hominid. They had a brain capacity of 650-
800cc. they probably did not eat meat.
3. Homo erectus: their fossils were found in java in 1981. They probably lived about 1.5 million years
back. They had a brain capacity of about 900cc. they probably ate meat.
4. Homo sapiens: their fossils were found in near East and Central Asia. He most has lived between 1,
00,000 to 40,000 years back. He had a brain capacity of about 1400cc. they used to hides to protect
the body and buried the dead. They moved across continents and developed into distinct races.
5. Modern man: This Homo sapiens arose during the ice age between 75000 -10000 years ago. He
spread all over the globe and learned to cultivate plants and domesticate animals. Pre-historic cave
art developed about 18000 years before. Agriculture started around 10000 years back. Human
settlements and civilizations started.