- Oct 31, 2000
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Alright, I have to write a small report and I can't come up with a conclusion. Yes, I know you are thinking "God - not another dumb high schoolers report!". But hey, since you guys are much smarter than me - you can lend some of your brains to help me out 
I have been working on the report for the last hour, so it's rushed and it's not very good. My AP biology teacher doesn't grade our reports by any guidelines - just as long as they sound good, so I'm not concentrating on great quality writing. Here's everyhting but the conclusion:
<FONT size=3><FONT face="Times New Roman"><SPAN style="mso-spacerun: yes">Conjoined twins, commonly known as Siamese twins, are some of the rarest and peculiar anomalies that occur in human nature and in biology. This disorder occurs when a fertilized female egg partially splits apart in a woman?s uterus, which forms two humans; both connected to each other. Overtime, we have witnessed many documentations of them, ranging from stories of Greek Gods to the reports of conjoined twins of today. Although many people know what conjoined twins are, few people know how this disorder occurs, and how or if it can be treated.
Throughout history, conjoined twins have appeared in myths and legends. The Greek and Roman God Janus had one body, but two heads. Centaurs, a combination of horse and man, may have been inspired by conjoined twins who often have four legs, and a common symbol, the Double-Headed Eagle, is common throughout central Europe.
In the 16th century, French doctor Ambroise Pare set out to discover the cause of this disorder. He came up with several inaccurate theories about why some twins are conjoined, including too much constriction in the womb, little space in a womb, tight clothing, and the position in which a woman sat while pregnant. These early theories were used when scientists two centuries later suggested that conjoined twins resulted from the blending of two independent twin embryos or from the fertilization of one egg by two sperm.
The most well known Siamese twins are Chang and Eng Bunker, who were joined by a narrow band of flesh in which their livers were connected. When the brothers immigrated into the United States from Siam, they could find little work due to their disability. They joined a popular carnival, in which they were billed as ?The Joined Siamese Twin Brothers?, and this is where the well known term ?Siamese Twins? originated from. Chang and Eng led fairly normal lives, in which they each had a wife, and many children.
Conjoined twins start in their lives the same way every human starts life. When an egg is fertilized in a woman?s uterus, it typically begins rapidly dividing and forming what will later be a human. In day one of the cell?s life, it becomes a ball of cells called a zygote. It is protected by an outer protective covering, or shell. The original cell has divided into many cells, and at this point continues this division until the fourth day. On the forth day, something unique happens. The outer covering opens up, and the zygote?s cells spill out. The cells then clump up in two, or more groups. The most common grouping is the grouping of two cells, but more can form. By day 10, these cell groupings then separate and form their own coverings. This is where an error may occur, resulting in conjoined twins. When the cells start to clump, they don?t become completely separated from each other, and form two connected and identical zygotes. As they form into embryos and then fetuses, the area where they weren?t completely separated is where they will be connected.
The possibilities of giving birth to conjoined twins ranges from 1 in 50,000 to 1 in 100,000. The majority of conjoined twins are females, and 75% of all twins are born stillborn, or die within the first 24 hours after birth. Depending where the twins are joined, the majority of them share organs, including the heart, brain, and liver. While in the womb, they also share a single umbilical cord, which is often large and misshapen. The types of conjunctions vary, but a vast majority fit into the following 6 categories based on their positions and where they are connected:
1. Thoraopagus ? joined at the thorax. This is the most common form of attachment, occurring in 35%-45% of all cases. These twins usually share a chest wall, or heart, or lungs.
2. Omphalopagus ? joined at the abdomen. This is the second most common form of attachment, accounting for at least 34% of cases. These twins typically share abdominal organs, and the attachment can span from the waist to the lower breastbone.
3. Pygopagus ? joined along the back. Accounting for 20% of cases, these twins can share a spinal column.
4. Ischiopagus ? joined at the pelvis. About 6% of all conjoined twins have this condition, with the twins joined by the coccyx and the sacrum.
5. Craniopagus ? joined at the head. 2% of all cases are with the twins joined at the head. The severity can range from just sharing the epidermis and cranial bones, to the sharing of one brain with two bodies.
6. Dicephalus ? one body with two separate heads and necks. The rarest of all cases, the twins usually have only one body, supporting two different heads and necks.
Although the majority of conjoined twins fit into these categories, the range of the conjunction varies greatly. One of the twins could form normally, while the other lacks many physiological features. They may be missing either the lower or upper half of their bodies, they may share limbs, and sometimes one of the twins is dependant on the other to make up for it?s missing features (heat, liver, etc).
In the majority of cases, when the conjoined twins are born, the first thing doctors assess is the possibility of separation. If the twins share only minor fusion of bones, and have complete sets of vital organs for which each could be sustained, doctors usually attempt separation. If the twins only have one vital organ (heart, liver, brain) to support them both, they are usually not separated, or they are separated, leaving only one surviving twin. Separation surgeries are usually very difficult due to the fact that doctors need to divide the twins separately, with equal amounts of their shared organs. Sometimes this is very difficult since one of the twin?s organs is usually weaker than the others, and in this case, the weaker twin depends on the stronger one to survive. Separation possibilities are unique in every case, due to the fact that all of the cases of conjoined twins are different.
Recently, there have been many successes and failures in conjoined twin separation. Last April, Jamuna and Ganga Shrestha were successfully separated. They had been conjoined at the head, sharing the same brain cavities. In an unrelated story, last year British courts ruled that two conjoined twins had to be separated against the parent?s wishes. The two children, whose identities were kept secret, were joined at the stomach. One baby was fully developed, and had regular organs, while the other didn?t have any lungs or a heart. The second twin was living off of the other twins organs. If separated, the weaker twin would die, but the stronger one would live. The parents didn?t want the twins separated because they saw it as killing one of them, but the courts ruled differently. This case is a testimonial about how complex and ethical separation can be. Many twins who have not been separated have led normal and productive lives, such as Chang and Eng Bunker.
*****conclusion goes here******
Thanks!</SPAN></FONT></FONT>
I have been working on the report for the last hour, so it's rushed and it's not very good. My AP biology teacher doesn't grade our reports by any guidelines - just as long as they sound good, so I'm not concentrating on great quality writing. Here's everyhting but the conclusion: <FONT size=3><FONT face="Times New Roman"><SPAN style="mso-spacerun: yes">Conjoined twins, commonly known as Siamese twins, are some of the rarest and peculiar anomalies that occur in human nature and in biology. This disorder occurs when a fertilized female egg partially splits apart in a woman?s uterus, which forms two humans; both connected to each other. Overtime, we have witnessed many documentations of them, ranging from stories of Greek Gods to the reports of conjoined twins of today. Although many people know what conjoined twins are, few people know how this disorder occurs, and how or if it can be treated.
Throughout history, conjoined twins have appeared in myths and legends. The Greek and Roman God Janus had one body, but two heads. Centaurs, a combination of horse and man, may have been inspired by conjoined twins who often have four legs, and a common symbol, the Double-Headed Eagle, is common throughout central Europe.
In the 16th century, French doctor Ambroise Pare set out to discover the cause of this disorder. He came up with several inaccurate theories about why some twins are conjoined, including too much constriction in the womb, little space in a womb, tight clothing, and the position in which a woman sat while pregnant. These early theories were used when scientists two centuries later suggested that conjoined twins resulted from the blending of two independent twin embryos or from the fertilization of one egg by two sperm.
The most well known Siamese twins are Chang and Eng Bunker, who were joined by a narrow band of flesh in which their livers were connected. When the brothers immigrated into the United States from Siam, they could find little work due to their disability. They joined a popular carnival, in which they were billed as ?The Joined Siamese Twin Brothers?, and this is where the well known term ?Siamese Twins? originated from. Chang and Eng led fairly normal lives, in which they each had a wife, and many children.
Conjoined twins start in their lives the same way every human starts life. When an egg is fertilized in a woman?s uterus, it typically begins rapidly dividing and forming what will later be a human. In day one of the cell?s life, it becomes a ball of cells called a zygote. It is protected by an outer protective covering, or shell. The original cell has divided into many cells, and at this point continues this division until the fourth day. On the forth day, something unique happens. The outer covering opens up, and the zygote?s cells spill out. The cells then clump up in two, or more groups. The most common grouping is the grouping of two cells, but more can form. By day 10, these cell groupings then separate and form their own coverings. This is where an error may occur, resulting in conjoined twins. When the cells start to clump, they don?t become completely separated from each other, and form two connected and identical zygotes. As they form into embryos and then fetuses, the area where they weren?t completely separated is where they will be connected.
The possibilities of giving birth to conjoined twins ranges from 1 in 50,000 to 1 in 100,000. The majority of conjoined twins are females, and 75% of all twins are born stillborn, or die within the first 24 hours after birth. Depending where the twins are joined, the majority of them share organs, including the heart, brain, and liver. While in the womb, they also share a single umbilical cord, which is often large and misshapen. The types of conjunctions vary, but a vast majority fit into the following 6 categories based on their positions and where they are connected:
1. Thoraopagus ? joined at the thorax. This is the most common form of attachment, occurring in 35%-45% of all cases. These twins usually share a chest wall, or heart, or lungs.
2. Omphalopagus ? joined at the abdomen. This is the second most common form of attachment, accounting for at least 34% of cases. These twins typically share abdominal organs, and the attachment can span from the waist to the lower breastbone.
3. Pygopagus ? joined along the back. Accounting for 20% of cases, these twins can share a spinal column.
4. Ischiopagus ? joined at the pelvis. About 6% of all conjoined twins have this condition, with the twins joined by the coccyx and the sacrum.
5. Craniopagus ? joined at the head. 2% of all cases are with the twins joined at the head. The severity can range from just sharing the epidermis and cranial bones, to the sharing of one brain with two bodies.
6. Dicephalus ? one body with two separate heads and necks. The rarest of all cases, the twins usually have only one body, supporting two different heads and necks.
Although the majority of conjoined twins fit into these categories, the range of the conjunction varies greatly. One of the twins could form normally, while the other lacks many physiological features. They may be missing either the lower or upper half of their bodies, they may share limbs, and sometimes one of the twins is dependant on the other to make up for it?s missing features (heat, liver, etc).
In the majority of cases, when the conjoined twins are born, the first thing doctors assess is the possibility of separation. If the twins share only minor fusion of bones, and have complete sets of vital organs for which each could be sustained, doctors usually attempt separation. If the twins only have one vital organ (heart, liver, brain) to support them both, they are usually not separated, or they are separated, leaving only one surviving twin. Separation surgeries are usually very difficult due to the fact that doctors need to divide the twins separately, with equal amounts of their shared organs. Sometimes this is very difficult since one of the twin?s organs is usually weaker than the others, and in this case, the weaker twin depends on the stronger one to survive. Separation possibilities are unique in every case, due to the fact that all of the cases of conjoined twins are different.
Recently, there have been many successes and failures in conjoined twin separation. Last April, Jamuna and Ganga Shrestha were successfully separated. They had been conjoined at the head, sharing the same brain cavities. In an unrelated story, last year British courts ruled that two conjoined twins had to be separated against the parent?s wishes. The two children, whose identities were kept secret, were joined at the stomach. One baby was fully developed, and had regular organs, while the other didn?t have any lungs or a heart. The second twin was living off of the other twins organs. If separated, the weaker twin would die, but the stronger one would live. The parents didn?t want the twins separated because they saw it as killing one of them, but the courts ruled differently. This case is a testimonial about how complex and ethical separation can be. Many twins who have not been separated have led normal and productive lives, such as Chang and Eng Bunker.
*****conclusion goes here******
Thanks!</SPAN></FONT></FONT>
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