Hits: 1260

• Video Field: https://www.youtube.com/watch?v=iKPw6-cTpIA

We're for all- ALL are for us for the greater interest of Humanism-Truth-Facts-Friendship-Unity-Participation including Physico-Mental Sound Health  with Spirituality enrichment through ''TOTAL HEALTH SOLUTION'' to a Well-furnished GOALofTruth alloted for all in real sense ;

From wikipedia & other reliable sources ( Poets, Writers, Thinkers, Researchers, Free Lancers, Philosophers, Theologists, Scientists, Orators, Sociologists and Photographers +Artists-Musicians & etc.) we can learn as follows : 

The sperm and the egg cell, which has been released from one of the female's two ovaries, unite in one of the two Fallopian tubes. The fertilized egg, known as a zygote, then moves toward the uterus, a journey that can take up to a week to complete. Cell division begins approximately 24 to 36 hours after the female and male cells unite. Cell division continues at a rapid rate and the cells then develop into what is known as a blastocyst. The blastocyst arrives at the uterus and attaches to the uterine wall, a process known as implantation.

The development of the mass of cells that will become the infant is called embryogenesis during the first approximately ten weeks of gestation. During this time, cells begin to differentiate into the various body systems. The basic outlines of the organ, body, and nervous systems are established. By the end of the embryonic stage, the beginnings of features such as fingers, eyes, mouth, and ears become visible. Also during this time, there is development of structures important to the support of the embryo, including the placenta and umbilical cord. The placenta connects the developing embryo to the uterine wall to allow nutrient uptake, waste elimination, and gas exchange via the mother's blood supply. The umbilical cord is the connecting cord from the embryo or fetus to the placenta.

After about ten weeks of gestational age—which is the same as eight weeks after conception—the embryo becomes known as a fetus.^[45] At the beginning of the fetal stage, the risk of miscarriage decreases sharply.^[46] At this stage, a fetus is about 30 mm (1.2 inches) in length, the heartbeat is seen via ultrasound, and the fetus makes involuntary motions.^[47] During continued fetal development, the early body systems, and structures that were established in the embryonic stage continue to develop. Sex organs begin to appear during the third month of gestation. The fetus continues to grow in both weight and length, although the majority of the physical growth occurs in the last weeks of pregnancy.

Electrical brain activity is first detected at the end of week 5 of gestation, but as in brain-dead patients, it is primitive neural activity rather than the beginning of conscious brain activity. Synapses do not begin to form until week 17.^[48] Neural connections between the sensory cortex and thalamus develop as early as 24 weeks' gestational age, but the first evidence of their function does not occur until around 30 weeks, when minimal consciousness, dreaming, and the ability to feel pain emerges.^[49]

Although the fetus begins to move during the first trimester, it is not until the second trimester that movement, known as quickening, can be felt. This typically happens in the fourth month, more specifically in the 20th to 21st week, or by the 19th week if the woman has been pregnant before. It is common for some women not to feel the fetus move until much later. During the second trimester, when the body size changes, maternity clothes may be worn.

Read more ...

Hits: 1134

• Video Field: https://www.youtube.com/watch?v=iKPw6-cTpIA

We're for all- ALL are for us for the greater interest of Humanism-Truth-Facts-Friendship-Unity-Participation including Physico-Mental Sound Health  with Spirituality enrichment through ''TOTAL HEALTH SOLUTION'' to a Well-furnished GOALofTruth alloted for all in real sense ;

From wikipedia & other reliable sources ( Poets, Writers, Thinkers, Researchers, Free Lancers, Philosophers, Theologists, Scientists, Orators, Sociologists and Photographers +Artists-Musicians & etc.) we can learn as follows : 

''A distinguishing characteristic of the class Mammalia is the presence of mammary glands. Mammary glands are modified sweat glands that produce milk, which is used to feed the young for some time after birth. Only mammals produce milk. Mammary glands are obvious in humans, because the female human body stores large amounts of fatty tissue near the nipples, resulting in prominent breasts. Mammary glands are present in all mammals, although they are normally redundant in males of the species.^[25]

Most mammalian females have two copies of the X chromosome, while males have only one X and one smaller Y chromosome; some mammals, such as the platypus, have different combinations.^[26][27] One of the female's X chromosomes is randomly inactivated in each cell of placental mammals while the paternally derived X is inactivated in marsupials. In birds and some reptiles, by contrast, it is the female which is heterozygous and carries a Z and a W chromosome while the male carries two Z chromosomes. In mammals, females can have XXX or X.^[28][29]

Mammalian females bear live young, with the exception of monotreme females, which lay eggs.^[30] Some non-mammalian species, such as guppies, have analogous reproductive structures; and some other non-mammals, such as some sharks, also bear live young.^[31]

In sex determination for mammals, female is the default sex, while in the poplar genus Populus the default is male''.^[32]

Read more ...