Page 128 - 86 human physiology part-2

Pregnancy and Birth

because, with the present state of technology, starting a stem cell line requires the destruction of a
human embryo and/or therapeutic cloning. Opponents of the research argue that this practice is a
slippery slope to reproductive cloning and tantamount to the instrumentalization of a human being.
Contrarily, some medical researchers in the field argue that it is necessary to pursue embryonic stem
cell research because the resultant technologies are expected to have significant medical potential, and
that the embryos used for research are only those meant for destruction anyway (as a product of in vitro
fertilization). This in turn, conflicts with opponents in the pro-life movement, who argue that an
embryo is a human being and therefore entitled to dignity even if legally slated for destruction. The
ensuing debate has prompted authorities around the world to seek regulatory frameworks and
highlighted the fact that stem cell research represents a social and ethical challenge.

• Reproductive Cloning

Reproductive Cloning is a technology used to generate an animal that contains the same nuclear
DNA as another currently or previously existing animal. Scientists transfer the genetic material from
the nucleus of a donor adult cell to an egg whose nucleus, and thus its genetic material has been
removed. The egg containing the DNA, now reconstructed, has to be treated with chemicals or electric
current in order to stimulate cell division. Once the cloned embryo reaches a suitable stage, it is
transferred to the uterus of a female host to continue development until birth. Currently this is illegal to
practice in the United States.

• Therapeutic Cloning

Recent research by researchers led by Anthony Atala of Wake Forest University and a team from
Harvard University has found that amniotic fluid, in addition to its main functions of cushioning a
growing fetus and providing buoyancy, is also a plentiful source of non-embryonic stem cells. These
cells have demonstrated the ability to differentiate into a number of different cell-types, including
brain, liver and bone.

Therapeutic Cloning refers to a procedure that allows the cloning of specific body parts and organs
to be used for medical purposes. Although this has not been realized, much research is being done on
the subject.

Pregnancy and Lactation

Mothers milk is ideal because it meets specific needs. Lactation is a neuroendocrine response in
milk production sucking stimulates the sensory nerve endings in the nipples it sends stimulus tot he
hypothalamus the hypothalamus stimulates anterior pituitary and prolactin is released. In milk let-down
the sucking stimulates sensory nerves in the nipples this stimulates the hypothalamus in the
hypothalamus this stimulates the posterior pituitary. This goes on to the release of oxytocin, because,
when sucking occurs this stimulates contraction of the cells around the alveoli in the mammary cells
milk then flows into the milk ducts causing milk let-down.

Breast milk provides almost all the nutrients required for the first 4-6 months. It contains
macronutrients like carbohydrates like lactose, fat such as high linoleic acid and protein like readily
digest and absorbed alpha-lactalbumin. Breast milk also contains an adequate supply of vitamins and
minerals, digestive enzymes, hormones and immunological factors.

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