Monday, November 21, 2011

PRE-NATAL DEVELOPMENT

Two kinds of sex cells or gametes are involved in human reproduction: the male gamete or the Sperm cell and the female gamete or the Ovum. When semen is deposited in the vagina the spermatozoa travels through the cervix and body of uterus, into the fallopian tube.  Fertilization of ovum usually takes place in the fallopian tube. The first sperm that penetrates fully into the egg, donates its genetic material (DNA).  The egg then polarizes and therefore repels any additional sperm.  The resulting combination is called zygote.
THE INITIAL STAGES OF HUMAN EMBRYO-GENESIS
The embryonic period in human beings at fertilization (penetration of the egg by the sperm) and continues until the end of 10th week of gestation (8th week by embryonic age).  The embryo spends next few days traveling down the fallopian tube. It starts out as a single cell zygote and then divide several times to form a ball of cell called a Morula.  Further cellular division is accompanied by the formation of small cavity between the cells. This stage is called a Blastocyst.  Up to this point there is no growth in the overall size of the embryo, as it is confined within a cyclo-protein shell, known as Zona pellucida.
The Blastocyst reaches the uterus at roughly the fifth day after fertilization. It is here that lysis of pellucida occurs. This allows the trophectoderm cells of Blastocyst to come into contact with, and here to, the endometrial cells of uterus. The trophectoderm will eventually give rise to extra-embryonic structures, such as placenta. Placenta and membranes are collectively referred to as conceptus or “product of conception”.
PRE-NATAL DEVELOPMENT
Prenatal development takes place during three periods: Germinal, Embryonic and Fetal periods.
Germinal Period
It is a period between conception and implantation (attachment to uterine wall – about 14 days).  The period occurs in the initial period of human embryogenesis
Embryonic Period
The period extends from 2 weeks to 8 weeks after conception.  Fourteen days after conception, the Blastocyst implants itself in the uterine wall. The embryonic period begins at the end of 2nd week. The embryo develops from a round layer of cells across the centre of Blastocyst. At 18 days embryo is about 0.0625 (1/16)thof an inch long. During its early weeks, human embryo closely resembles those of other vertebrate animals. The embryo has a tail and traces of gills, both of which will soon disappear. The head develops before the rest of the body. Eyes, nose and ears are not yet visible at one month, but a backbone and vertebral canal have formed. Small buds that will develop into arms and legs appear. The heart form and start beating: other body systems begin to take shape.
The Fetal Period
The period extends from 8 weeks through remainder of pregnancy.  By the end of the embryonic period (2 months), the fetus has developed the first bone structure and distinct limbs and digits that take in human form. Major blood vessels form and internal organs continue to develop. By the end of the first trimester (1/3rd length of pregnancy or 12.7 weeks).The fetus is about 3 inches long: most major organs are present, a large head and face are well developed, and heart beat can be detected with a stethoscope.
By the end of 4th or 5th period (month) can usually feel that movement. The skin of fetus is covered with fine hair, usually shed before birth. At the end of 5th month, fetus weighs about 1 pound and is about 12 inches long. It sleeps, wakes, sucks and moves its position. At the end of 6th month eyes, eyelids and eyelashes form. The fetus eyes are light sensitive and he/she can hear uterine sounds and respond to vibrations and acoustical stimulation.The head and body of the fetus become more proportionate during  3rd   trimester .Fat layers form under the skin. By the end of 8th month, the fetus weighs about 5 pounds and is about 18 inches long.
By the end of the 9th month, the nails have grown to the end of fingers and toes. The skin becomes smoother and is covered with a protective waxy substance called Vernix Caseosa.The baby is ready for delivery.

Wednesday, April 6, 2011

SEXISM

            Sexism is a term coined in the mid-20th century.  It is the belief or attitude that one sex is inherently superior to, more competent than, or more valuable than the other. Sexism primarily involves hatred of, or prejudice towards, either sex as a whole, or the application of stereotypes of masculinity in relation to men, or of femininity in relation to women.

BENEVOLENT SEXISM
            Benevolent sexism is a term which denotes “positive” ideas and attitudes of men towards women, which are based on the assumption that men must take care of and sacrifice themselves for women (Thaindian News, 2011).  It is a chivalrous attitude toward women that feels favorable but is actually sexist because it casts women as weak creatures in need of men's protection (Yahoo! Answers).  Like hostile sexism, it is an ideology that supports gender inequality, and in some ways benevolent sexism can be even more insidious.
Benevolent sexism may seem harmless, noble, or even "romantic," but studies suggest that benevolent sexist attitudes of men towards women in our society have negative impacts.  Such affection or protection cannot be called as innocent since women are here assumed to be inferior to men. 
Benevolent justifications for discrimination (e.g., "Women should forego a career because they excel at childcare") are more likely to be accepted than hostile justifications (e.g., "Women should forego a career because they lack ability"). However, women who are more likely than men to reject hostile sexism, they often endorse benevolent sexism -- especially in countries high in hostile sexism, where male protection is most appealing. Ironically, it may be that high levels of hostile sexism among men lead to high levels of benevolent sexism among women


HOSTILE SEXISM
Hostile sexism, as opposed to benevolent sexism, is a negative emotion directed specifically towards women, such as anger, resentment, etc. Hostile sexism has three sources: dominant paternalism, or a need to control women; competitive gender differentiation, which is an emphasis on the differences between women and men and a devaluation of women; and hostile heterosexuality is viewing sex a resource and women as controlling sex for their own purposes.
Hostile sexism is the type that results in men believing that women are inferior. Women are far more likely to be opposed to hostile sexism than men are.  Hostile Sexism is the traditional idea of sexism involving negative feelings towards women. Individuals high in hostile sexism are more likely to endorse items such as “Women are too easily offended” and “Once a women gets a man to commit to her, she usually tries to put him on a tight leash.”  High hostile sexists are likely to have less favorable attitudes towards women in a nontraditional role (career woman).
There is a correlation between hostile sexism and benevolent sexism in men, meaning that men who have hostile sexist attitudes, such as thinking a woman's place is in the kitchen, also tend to have benevolent sexist attitudes, such a believing women should be protected by men.  According to Glick et al (2000), male dominance creates hostile sexism, but men's dependence on women fosters benevolent sexism--subjectively positive attitudes that put women on a pedestal but reinforce their subordination. Research done by Glick et al (2000) in a sample of 15,000 men and women from 19 nations showed that (a) hostile sexism and benevolent sexism are coherent constructs that correlate positively across nations, but (b) hostile sexism predicts the ascription of negative and BS the ascription of positive traits to women, (c) relative to men, women are more likely to reject hostile sexism than benevolent sexism, especially when overall levels of sexism in a culture are high, and (d) national averages on benevolent sexism and hostile sexism predict gender inequality across nations. These results challenge prevailing notions of prejudice as an antipathy in that benevolent sexism (an affectionate, patronizing ideology) reflects inequality and is a cross-culturally pervasive complement to hostile sexism.