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The dynamic process by which the single-cell human zygote(zī΄gōt)[1] becomes a 100 trillion (1014) cell adult[2] is perhaps the most remarkable phenomenon in all of nature.
Researchers now know that many of the routine functions performed by the adult body become established during pregnancy – often long before birth.[3]
The developmental period before birth is increasingly understood as a time of preparation during which the developing human acquires the many structures, and practices the many skills, needed for survival after birth.
سُہہ لگاتار يا نہ ژينہ وُون عمل يمہٕ سيئتی اکھ انسٲنی سیل زے گوٹ بنن چھ اکھ بتھ سیلہ ووُل جوان چُھ شاید۔ سٲرٕسی قدرتس منڒ ساروی کھوتۂ زیادہ یادگار (قابل زکر) عمل۔
تحقیق کرن وٲلی چھ وونیٕ زانان زِواراہ معمولچہٕ کٲمیہ۔ یمہٕ اکھ جوان جسم انجام چُھ دوان۔ چھ حملسٔ دوران مکمل گژان واراھٕ لٹہٕ ذِینہ بڒونہہ واراہ کال۔
زینہ بڒونہم بنہ نوکُ وکھ چُھ زیادہ زبرپٲٹھی سمجھنہ یوان تیاری ہُند وکھ یتھ منز بنن وۄل انسان؛ چُھ پراۉان واڒاہ ڈانچہ ییہ چُھ عملاوان وارہ ہُنرہ؛ یمہ زینہ پتھ زندہ روزنۂ خٲطرہ ضرورت چھ
Pregnancy in humans normally lasts approximately 38 weeks[4] as measured from the time of fertilization,[5] or conception,[6] until birth.
During the first 8 weeks following fertilization, the developing human is called an embryo,[7] which means "growing within."[8] This time, called the embryonic period,[9] is characterized by the formation of most major body systems.[10]
From the completion of 8 weeks until the end of pregnancy, "the developing human is called a fetus," which means "unborn offspring." During this time, called the fetal period, the body grows larger and its systems begin to function.[11]
All embryonic and fetal ages in this program refer to the time since fertilization.[12]
انسناننٔ منز چھ حمل یاڈنب لگُن عام پٲٹھی الہ پلہ اڑترہن ہفتین روزان۔ یہٕ وکھ چُھ حمل لگنۂ پیٹھ مینۂ آمتھ۔ یا حمل لگنہ پیٹھٕ زینہ وکھتس تٲم۔
حمل ٹھہرنہ پتہ گوڑنیکو آٹھو ہفتو پتۂ چھ۔ بنن وٲٕلس انسانس ونان ایمبریو (Embryo)۔ یمکُھ مانۂ گواندری بڑنٔ ٳتھ وکتس یتھ ایمبر Embryonic Period ینا کھ وکھ ونان چھ۔ چھ پرزناۉنہ یوان بڑی بڑی جسمانی نظام بنہ نہ سیتی
آٹھ ہفتہ اندواتتھ تالا گاتہٕ حمل اندواتنس تام بنن والس انسانس چُھ فیٹس (Fetus) ونان یتھٔ ونان چھٔ زینہ برونہم ینۂ وۄل۔ اتھ وقتس یتھ فیٹل وکھ ونان چُھ چُھ جسم واراہ بڑان تۂ نظام چُھ ہیوان کام کرنی
اتھ پروگرامس منز چھ ساری ایمبر یانکھ تہٕ فیٹل وکھ فرٹيلائيزيشن پیٹھے شروع گژھان۔
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[1]
Gasser, 1975, 1.
[2]
Guyton and Hall, 2000, 2;
Lodish et al., 2000, 12.
[3]
Vindla and James, 1995, 598.
[4]
Cunningham et al., 2001, 226;
O’Rahilly and Müller, 2001, 92.
[5]
O’Rahilly and Müller, 1987, 9.
[6]
Spraycar, 1995, 377 & 637.
[7]
O’Rahilly and Müller, 2001, 87.
[8]
Quote from Ayto, 1990, 199.
[9]
Human development during the 8-week embryonic period has been divided into a series of 23 stages called Carnegie Stages. These stages are well described in O’Rahilly and Müller, 1987. Because human growth is unique and dependent on multiple factors, different embryos may reach a certain developmental milestone or a certain size at slightly different ages. This internationally-accepted staging system provides a way to describe development independent of age and size. Each of the 23 Carnegie Stages has specific structural features. As we describe various milestones of development, the Carnegie Stage at which they occur will be noted by a designation such as: [Carnegie Stage 2]. See Appendix B for additional information relating embryonic staging and age assignments.
[10]
Moore and Persaud, 2003, 3.
[11]
Quotes from Moore and Persaud, 2003, 3: “After the embryonic period (eight weeks), the developing human is called a fetus.“ Also see O’Rahilly and Müller, 2001, 87.
[12]
This convention, termed “postfertilization age“ by O’Rahilly, has been long preferred by embryologists. [see Mall, 1918, 400;
O’Rahilly and Müller, 1999b, 39;
O’Rahilly and Müller, 2001, 88 & 91.] Obstetricians and radiologists typically assign age based on the time elapsed since the first day of the last menstrual period prior to fertilization. This is correctly termed “postmenstrual age“ and begins 2 weeks before fertilization occurs. To summarize: postmenstrual age = postfertilization age + 2 weeks. Therefore, postmenstrual age equals approximately 2 weeks at the time of fertilization. The commonly used term “gestational age“ has been used with both age conventions and is best either avoided or carefully defined with each use.
Page 3
Biologically speaking, "human development begins at fertilization,"[13] when a woman and a man each combine 23 of their own chromosomes through the union of their reproductive cells.
A woman's reproductive cell is commonly called an "egg" but the correct term is oocyte (ō´ō-sīt).[14]
Likewise, a man's reproductive cell is widely known as a "sperm," but the preferred term is spermatozoon (sper´mă-tō-zō´on).[15]
Following the release of an oocyte from a woman's ovary in a process called ovulation (ov´yū-lā´shŭn),[16] the oocyte and spermatozoon join within one of the uterine tubes,[17] which are often referred to as Fallopian tubes.
The uterine tubes link a woman's ovaries to her uterus or womb.
The resulting single-celled embryo is called a zygote,[18] meaning "yoked or joined together."[19]
حیاتاتی علم مطابق فرٹيلائيزيشن پٹھے چُھ ہیۉان انسان بنُن یلہٕ اکھ زنان تۂ مرد رلاوان تروۂ 23 پننیٕ پننیٕ کرؤ موزم پیداواری سیلہٕ (Cells) جورہ نۂ سیئتی
زنانہ ہینز پیداواری سیلہ چُھ عام پٲٹھی ٹھول ونانٔ۔ مگر اوسیٹ چُھ صیح لفظ۔
یتھے پٲٹھی چُھ مردہ سنز پیداواری سیلہ عام پٲٹھی ونان سئپرم مگر جان لفظ چُھ سپُر میٹازون (Super Metazoon)
زنٲنۂ ہئنز بچہ دٲنہٕ منز یلہ اوسیٹ یلۂ (نیران) چُھ گژھان۔ تتھ عملہ چُھ اویولیشن (Ovulation) ونان اوسیٹھ تۂ سپرمیٹازون چھ رلان۔ ٲکس بچہ دٲنہ ہنزہ نالہ منز یتھ عام پاٹھی Fallopian Tube ونان چھ
بچہ دٲنہ ہنزہ نالہ چھ زنانۂ ہنزنٔ بچۂ دٲنن رلاوٲن تسندسٕ شکمس سیتی
ٲتھ اکسی (Embryo) سیلہ چھ ونان زٔیگوٹ (Zygote) ٲمیکھ مٲنہ گو/رلاوتھٔ (پانہٕ وانی رلاوتھ)
DNA
The zygote's 46 chromosomes[20] represent the unique first edition of a new individual's complete genetic blueprint. This master plan resides in tightly coiled molecules called DNA. They contain the instructions for the development of the entire body.
DNA molecules resemble a twisted ladder known as a double helix.[21] The rungs of the ladder are made up of paired molecules, or bases, called guanine, cytosine, adenine, and thymine.
Guanine pairs only with cytosine, and adenine with thymine.[22] Each human cell contains approximately 3 billion (3×109) base pairs.[23]
The DNA of a single cell contains so much information that if it were represented in printed words, simply listing the first letter of each base would require over 1.5 million (1.5×106) pages of text![24]
If laid end-to-end, the DNA in a single human cell measures 3⅓ feet or 1 meter.[25]
If we could uncoil all of the DNA within an adult's 100 trillion (1014) cells, it would extend over 63 billion (6.3×1010) miles. This distance reaches from the earth to the sun and back 340 times.[26]
Cell Division
Approximately 24 to 30 hours after fertilization, the zygote completes its first cell division.[27] Through the process of mitosis, one cell splits into two, two into four, and so on.[28]
Early Pregnancy Factor (EPF)
As early as 24 to 48 hours after fertilization begins, pregnancy can be confirmed by detecting a hormone called "early pregnancy factor" in the mother's blood.[29]
DNA
زیگوٹکھ شیتاجی (46) کروموزُم چھ نمٲندگی کران گوڈ ٕنکی چھاپوکُھ اکس نوس انسانہ سندہ مکمل جینی نقشکھ یہٕ ماسٹر پلان چُھ روزان DNA ڈی این ٲیس منز چیرہ وٕلتھ خُولن ہندس صورتس منز یمن منز چھ آسان ترقی پروٳنکی ہدایت سٲری جسم خٲطر
ڈی،این اے چھ ہشئر تھاوان ٲکس ورلد ہیرہ ہندی پٲٹھی یتھ ڈبل ہیلکس ونان چُھ امہ ہیرہ ہند پٲوٕچھی آسان بنے فخرزرن ہند یو جوروِسیتیٔ یا بنیادو سیئتی یتھ گوی نٲین سیٹو سٲین، ایڈی نٲین تہٕتھیامٲین ونان چُھ
گوی نٲین چھی جُوربناوان صرف سیٹوسٲنس سیئتی تۂ ریڈی نٲین تھیامٲنس سیتی پرتھ اکھس انسانی سیلہٕ (cell) منز چھٕ آسان الہ پلہ ترہ بلین۔ یژہ بنیادی جورٕہ۔
اکسی سیلہ ہندس ڈی، این ٲیس منز چھ تیژہ معلومات۔ زِہرگاہ تمن لفظن اندر لیکھو۔ صرف پرتھ بنیادچ اکہٕ لفظوکھ گوڈنکی اچھر سیتی۔ لیکھن لگن کتابہ ہندٕ 1.5 ملین ورق۔
ہرگاہ اکھ اندبیس اندس سیئتی رلٲۉو۔ اکسی انسانی سیلہ منز ڈی،این اے، بنہ 31/3 فٹ یا اکھ میٹر۔
اگر،ڈی،این،ایس ورمژ راوۄ۔ اکس جوان انسانہ سند اکھ ہتھ کھرب سیلہ ٲمیکھ پورہ زیچھر واتہٕترہاٹھ (63) کھرب میلن تام یہ گۉ زمینہ پیٹھ آفتابس تام تۂ تتہ پیٹھ وٳلس زینس تام زیچھر تربتھ تہ ژتجٲہ لٹہ۔
Cell Division
فرٹیلائیزیشن یارلنہ پتہ الہپلہ ژوہیہ پیٹھ ترہن گھنٹن تام چُھ زیگوٹ چُھ پورہ کران گوڑنیکھ سیل ڈیوژن (Cell Division) مٲٹاسیس عملہ سیئتی اکھ سیل چھ دون منز تہٕ زِہ ژورن منز پٹھان یابیون گژھان تۂ بہوے عمل برنہہ پکان۔
Early Pregnancy Factor (EPF)
فرٹیلائیزیشنس یارلنہ پتہ ژوہیہ پیٹھ اڑتٲجی گھنٹہ پتھ۔ ہیکو ہارمون کہ زریعہ حمل لگ نوک پے کڑتھ یتھ ماجہ ہندس خونس منز گوڈنیکھ حمل ٹھہرن ونان چھ۔
[13]
Quote from Moore and Persaud, 2003, 16;
From O’Rahilly and Müller, 1987, 9: “Fertilization is the procession of events that begins when a spermatozoon makes contact with an oocyte or its investments and ends with the intermingling of maternal and paternal chromosomes at metaphase of the first mitotic division of the zygote.“ See Carlson, 2004, 3;
O’Rahilly and Müller, 2001, 8. [Carnegie Stage 1]
[14]
O’Rahilly and Müller, 2001, 25: “The term ‘egg’ should be discarded from human embryology.“ From O’Rahilly and Müller, 1987, 9: “The term ‘egg’ is best reserved for a nutritive object frequently seen on the breakfast table.“
[15]
O’Rahilly and Müller, 2001, 23-24.
[16]
O’Rahilly and Müller, 2001, 30.
[17]
Dorland and Bartelmez, 1922, 372;
Gasser, 1975, 1;
Mall, 1918, 421;
O’Rahilly and Müller, 2001, 31.
[18]
Gasser, 1975, 1;
O’Rahilly and Müller, 2001, 33.
[19]
Quote from Saunders, 1970, 1;
Spraycar, 1995, 1976.
[20]
Guyton and Hall, 2000, 34.
[21]
Guyton and Hall, 2000, 24;
Watson and Crick, 1953, 737.
[22]
Guyton and Hall, 2000, 24;
Lodish et al., 2000, 103;
Watson and Crick, 1953, 737.
[23]
Lodish et al., 2000, 456.
[24]
See Appendix A.
[25]
See Appendix A;
Alberts et al., 1998, 189.
[26]
See Appendix A.
[27]
Hertig, 1968, 26;
Hertig and Rock, 1973, 130;
(cited by O’Rahilly and Müller, 1987, 12);
Shettles, 1958, 400.
[28]
Guyton and Hall, 2000, 34.
[29]
Moore and Persaud, 2003, 33 & 60;
Morton et al., 1992, 72;
Nahhas and Barnea, 1990, 105.
Page 4
By 3 to 4 days after fertilization, the dividing cells of the embryo assume a spherical shape and the embryo is called a morula (mōr´ū-lă).[30]
By 4 to 5 days, a cavity forms within this ball of cells and the embryo is then called a blastocyst.[31]
The cells inside the blastocyst are called the inner cell mass and give rise to the head, body, and other structures vital to the developing human.[32]
Cells within the inner cell mass are called embryonic stem cells because they have the ability to form each of the more than 200 cell types contained in the human body.[33]
فرٹیلائیزیشن پتۂ تریۂ پیٹھ ژورن دوہو پتہ۔ شکمس منز تقسیم گژونہ سیلہ چھ رٹان گول شکل۔ تہ اتھٔ ایمبر یوہس چھ ونان ماریولا (Morula)
ژورٕ پیٹھ پٲنژن دوہن اندرٕ چُھ اتھ ماریولا بالہ منز اکھ کھوڑہیؤ بنان۔ اتھ ایمبر یوہس چھ ونان بلاسٹوسسِٹ (Blasto Cyst)
(Blasto Cyst) ہنزن ٲندریمن سیلن چُھ۔ ونان اندرم سیل ماس یاہج کج شکلہٕ واجنی بال۔ امہ سیئتی چھ بنان کلہ، جسم تہ باقی وسُکھان۔ یم وسکان چُھ بڑہ ونس انسانہ سندہ خاطرہ اہم آسان
اتھ اندرمس سیل ماس منز سیلن۔ چُھ ونان ایمبر یٲنکھ سٹم سیلز (Embryonic Stem Cells) تکیازِ تمن چھٕ ۔ زِہ ہتھ کھوتۂ زیادہٕ سلہ ہند قسم بنا دنکھ قابلیت آسان۔ یم انسانہ سندٕس جسمس منز آسان چُھ
After traveling down the uterine tube, the early embryo embeds itself into the inner wall of the mother's uterus. This process, called implantation, begins 6 days and ends 10 to 12 days after fertilization.[34]
Cells from the growing embryo begin to produce a hormone called human chorionic gonadotropin (human kō-rē-on'ik gō'nad-ō-trō'pin), or hCG, the substance detected by most pregnancy tests.[35]
HCG directs maternal hormones to interrupt the normal menstrual cycle, allowing pregnancy to continue.[36]
یلہ یہٕ یوٹرین ٹیوبہ منز بکینہ بیتھ۔ یلہ گوڑنکھ ایمبریو یوٹرین نالہ منز بون وسان چُھ ۔ ییہٕ چھ ماجہ ہندس شکمس اندرمس دیوارس سیتی روزان تۂ قرار کران اتھ عملہ چھ ونان رٹتھ روزان یا ایمپلانٹیشن تہ حمل لگنہ پیٹھ چُھ دہن یا باین دوہن تام اندروٲ تان
بڑہ ونہ ایمبریو جہ سیلہ چھ اکھ ہارمون لاگان پیدہ کرُن یتھ (Human Chronic Gowadotropin) یا HCG چھٕ ونٲن حمل لگنس چھ گوڑیہوے مادہ بِد کڑان۔
HCG ماجہ ہندین ہارمونن اشارہ کرٲن۔ زِماہورای ہُندر عمل گژِتھامہ روزن تۂ حمل گژھ برونہہ پکُن
Following implantation, cells on the periphery of the blastocyst give rise to part of a structure called the placenta (plă-sen'tă), which serves as an interface between the maternal and embryonic circulatory systems.
The placenta delivers maternal oxygen, nutrients, hormones, and medications to the developing human; removes all waste products; and prevents maternal blood from mixing with the blood of the embryo and fetus.[37]
The placenta also produces hormones and maintains embryonic and fetal body temperature slightly above that of the mother's.[38]
The placenta communicates with the developing human through the vessels of the umbilical (ŭm-bil'i-kăl) cord.[39]
The life support capabilities of the placenta rival those of intensive care units found in modern hospitals.
تھامہ یاروہتھ گژھنہ یتہً چھ ایمبریوچہ۔ Blastocyst چھ نیبرم سیلہٕ چھ اکس تتھس ڈانچس بناوان یتھ ناف یا (Placenta) ونٲن چھٕ یُس ماجہٕ تہ ایمبریوہس درمیٲن۔ خون کہ گردشس رلٲوان چُھ
ناف (Placenta) چُھ مٲجہ پیٹھ بچس تام آکسیجن، خوراک ہارمون تہ دوا واتہ ناوٲن۔ نکارہ چیزہ چھ دور کران۔ تۂ ماجہ ہندس خونس سیتھٕ چُھ بچہ سندس خونس رلنہ نشہٕ بچاوان
ناف تہٕ چھ ہارمون پیدہ کرٲن تہٕ برقرٲر تھاوان، ایمبریانکھ تہ فیٹلٔ حرارت۔ ماجہٕ ہندہ حرارتہ کھوتہ زراز یادہ پہنٔ۔
ناف چھ بڑہ ونس بچس سیتی رابطہ کرٲن اکہ نالی داررزہ ہندہ زریعہ
زندگی مدرکرنچہ قابلیت یس نافہٕ منز آسان چُھ ہیکن۔ ازکہ زمانہ کین ہسپتالن منز ICU سہی سیتھ مقابلہ کرتھ
[30]
Gasser, 1975, 1;
O’Rahilly and Müller, 2001, 37;
Spraycar, 1995, 1130: “Morula“ is derived from the Latin word morus meaning “mulberry.“ [Carnegie Stage 2]
[31]
O’Rahilly and Müller, 2001, 39. [Carnegie Stage 3]
[32]
Gasser, 1975, 1;
O’Rahilly and Müller, 2001, 39;
Sadler, 2005, 6.
[33]
Alberts et al., 1998, 32. For a discussion and definition of embryonic stem cells see the website of the National Institutes of Health: http://stemcells.nih.gov/infoCenter/stemCellBasics.asp#3
[34]
O’Rahilly and Müller, 2001, 40;
Implantation begins with attachment of the blastocyst at about 6 days after fertilization. [Attachment of the blastocyst to the inner wall of the uterus is a transient event and is the hallmark of Carnegie Stage 4.] See also Adams, 1960, 13-14;
Cunningham et al., 2001, 20;
Hamilton, 1949, 285-286;
Hertig, 1968, 41;
Hertig and Rock, 1944, 182;
Hertig and Rock, 1945, 81 & 83;
Hertig and Rock, 1949, 183;
Hertig et al., 1956, 444. [Carnegie Stage 5]
[35]
Chartier et al., 1979, 134;
Cunningham et al., 2001, 27;
O’Rahilly and Müller, 2001, 43.
[36]
Cunningham et al., 2001, 20 & 26-27;
O’Rahilly and Müller, 2001, 31.
[37]
Hertig, 1968, 16;
Cunningham et al., 2001, 86 & 136;
For a detailed description of the placenta see Hamilton and Boyd, 1960. For a detailed description of the placenta vasculature see Harris and Ramsey, 1966. This separation of maternal and fetal blood is almost but not quite perfect as a
small number of fetal cells may be found in the maternal circulation and vice-versa. See Cunningham et al., 2001, 96 & 136.
[38]
Liley, 1972, 101;
O’Rahilly and Müller, 2001, 78-79.
[39]
For a detailed description of umbilical cord formation see Florian, 1930.
Page 5
By 1 week, cells of the inner cell mass form two layers called the hypoblast and epiblast.[40]
The hypoblast gives rise to the yolk sac,[41] which is one of the structures through which the mother supplies nutrients to the early embryo.[42]
Cells from the epiblast form a membrane called the amnion (am-nē-on),[43] within which the embryo and later the fetus develop until birth.
اکھ ہفتہ گذرنہ پتہ۔ اندرمہ سیل ماس چہ سیلہٕ۔ چھ بناوان زہٕ نہنۂ یتھHypoblast یہٕ اېپی بلاسٹھ، Epiblast ونان چھ
Hypoblast بناوان Yolk Sacs یسُ ڈانچو منزی اکھ تیوتھ ڈانچہ چُھ ۔ یمہٕ کہ زریعہ مٲج چھ بچس خوراک وا تناوان یلہ ایمبریو گوڑنکہ وقتس منز آسان چھ
Epiblast چھہ سیلہ بناوان اکھ پردہ ہیویتھ Amnion ونان چھ ۔ یتھ منز گوڑہ ایمبریو (Embryo) تہٕ امہ پتۂ فیٹس (Fetus) زیونس تام بڑان چُھ
By approximately 2½ weeks, the epiblast has formed 3 specialized tissues, or germ layers, called ectoderm, endoderm, and mesoderm.[44]
Ectoderm gives rise to numerous structures including the brain, spinal cord, nerves, skin, nails, and hair.
Endoderm produces the lining of the respiratory system and digestive tract and generates portions of major organs such as the liver and pancreas.
Mesoderm forms the heart, kidneys, bones, cartilage, muscles, blood cells, and other structures.[45]
By 3 weeks the brain is dividing into 3 primary sections called the forebrain, midbrain, and hindbrain.[46]
Development of the respiratory and digestive systems is also underway.[47]
As the first blood cells appear in the yolk sac,[48] blood vessels form throughout the embryo, and the tubular heart emerges.[49]
Almost immediately, the rapidly growing heart folds in upon itself as separate chambers begin to develop.[50]
The heart begins beating 3 weeks and 1 day following fertilization.[51]
The circulatory system is the first body system, or group of related organs, to achieve a functional state.[52]
اڈیئ ہفتہٕ گذرتھ چُھ اېپی بلاسٹھ(Epiblast) چُھ بناوان ترہ خاص ٹِشوٕ یا جرم تہٕ یتھٔ ایکٹوڈرم (Ecto Derm) اینڈوڈرم (Endo Derm) میزوڈرم(Meso Derm) ونان چھٕ
ایکٹوڈرم(Acto Derm) چھ بناوان واراہ ڈانچہٕ دماغ سٲن گدود (Spinal Cord) رگہ (Nervs) مُسلہٕ(Skin) نم تہٕ مس
Endoderm چُھ نظام تفسچ لٲننگ بناوان ییہ ہاظمہ نالی بیہ چُھ پیدہ کران بڈی تٲن مثالہ: کرہنۂ مٲز تہ لبہ لب
Mesoderm چھ بنٲوان دٕل بکُہ وچہ (گردہ) ٲڈجہٕ، ترکہ اڈجہٕ، پٹہ تہٕ، خونہ چہٕ سیلہٕ تہ بیہٕ باقی ڈانچہ
ترہ ہفتہ گذرتھ چھ دماغ چھ ترین بنیادی حصن منز با گراونہ یوان یتھ برنہم دماغ منزیم دماغ تہٕ پتئیم دماغ وننہ چُھ یوان
نظامِ نفس تہٕ ہاظمہ تۂ چُھ سیتٕ سیئتی بنان
یام گوڑنکٸ خون سیلہٕ (Blood Cell) Yolk Sacs منز نُنہ چُھ نیرٲن تہٕ خونہ چہٕ نالہ چھ بنٲن سارسی ایمبریوہس منز یتہٕ پٳٹھی چُھ ٹیوب ہیُودلٕ بنٲن
امہٕ پتہ سیتی چُھ تیزی سٲن بڑون دل چُھ پانے وٹنہ یوٲن بیئون بیئون کمرہ ہیوی چھ ہیوان بڑنی تہٕ بننئ
دل چُھ ہیوان دُبہ رائے کرنی ترہ ہفتہ تہٕ اکھ دوہ گژتھ حمل لگنہ پتہ۔
خونہ کہ گردش کرنکھُ نظام چُھ گڈنکھ نظام یااتھ سیت وابستہ انگن ہُند گرُوپ یُس پورہ پٳٹھی کام چھ ہیوان کرُون
Between 3 and 4 weeks, the body plan emerges as the brain, spinal cord, and heart of the embryo are easily identified alongside the yolk sac.
Rapid growth causes folding of the relatively flat embryo.[53] This process incorporates part of the yolk sac into the lining of the digestive system and forms the chest and abdominal cavities of the developing human.[54]
تریوہ پیٹھ ژون ہفتن منز باگ چھ جسمک پلان نون نیران بوتھ دماغ گدودتہ ایمبریو کہ دل چُھ آسانی سٲن پرزناون یوان Yolk Sac سیت سیتی
تیزی سٲن بڑن چُھ تہہ کران سوس ایمبریوہس (Embryo) یہ عمل چُھ سیتی تھاوان Yolk Sac کسی حصس تتھ تہس سیتی یوس نظام ہاظمہ ہس سیتی چُھ آسان تۂ بناوان چُھ سینۂ بیہٕ یڈہُند خولٔ امس بڑونس بچۂ سُند
[40]
O’Rahilly and Müller, 2001, 39.
[41]
Moore and Persaud, 2003, 50;
O’Rahilly and Müller, 2001, 82. [Carnegie Stages 5 & 6];
In humans, the term “yolk sac“ has fallen out of favor among some embryologists (including O’Rahilly and Müller) because it is not a nutrient reservoir and does not contain yolk. The technically preferred term is umbilical vesicle. This structure plays a vital role in the transfer of nutrients from mother to embryo before placental circulation becomes fully functional.
[42]
Campbell et al., 1993, 756;
Kurjak et al., 1994, 437;
O’Rahilly and Müller, 2001, 82.
[43]
O’Rahilly and Müller, 1987, 29;
O’Rahilly and Müller, 2001, 43. [Carnegie Stages 4-5]
[44]
O’Rahilly and Müller, 2001, 14 & 135. [Carnegie Stage 7];
It should be noted there are many examples of organs derived from multiple germ layers. For instance, the liver is largely derived from endoderm but contains blood vessels and blood cells derived from mesoderm and nerves of ectodermal origin.
[45] Moore
and Persaud, 2003, 80 & 83; Sadler, 2005, 9.
[46]
Bartelmez, 1923, 236;
Müller and O’Rahilly, 1983, 419-420 & 429;
O’Rahilly and Gardner, 1979, 123 & 129;
O’Rahilly and Müller, 1984, 422;
O’Rahilly and Müller, 1987, 90;
O’Rahilly and Müller, 1999a, 47 & 52. [Carnegie Stage 9]
[47]
DiFiore and Wilson, 1994, 221;
Fowler et al., 1988, 793;
Grand et al., 1976, 793-794 & 796 & 798;
O’Rahilly, 1978, 125;
O’Rahilly and Boyden, 1973, 238-239;
O’Rahilly and Müller, 1984, 421;
O’Rahilly and Tucker, 1973, 6 & 8 & 23;
Streeter, 1942, 232 & 235.
[48]
Carlson, 2004, 117.
[49]
Gilmour, 1941, 28;
O’Rahilly and Müller, 1987, 86. [Carnegie Stage 9]
[50]
Campbell, 2004, 14;
Carlson, 2004, 116 & 446;
Navaratnam, 1991, 147-148;
O’Rahilly and Müller, 1987, 99. [Carnegie Stage 10]
[51]
Campbell, 2004, 14;
Carlson, 2004, 430;
De Vries and Saunders, 1962, 96;
Gardner and O’Rahilly, 1976, 583;
Gilbert-Barness and Debich-Spicer, 1997, 650;
Gittenger-de Groot et al., 2000, 17;
van Heeswijk et al., 1990, 151;
Kurjak and Chervenak, 1994, 439;
Navaratnam, 1991, 147-148;
O’Rahilly and Müller, 1987, 99;
Wisser and Dirschedl, 1994, 108. [Carnegie Stage 10, possibly late Stage 9]
[52]
Moore and Persaud, 2003, 70: “The cardiovascular system is the first organ system to reach a functional state.“
[53]
Moore and Persaud, 2003, 78.
[54]
Gasser, 1975, 26;
Moore and Persaud, 2003, 78.
Page 6
The heart typically beats about 113 times per minute.[57]
Note how the heart changes color as blood enters and leaves its chambers with each beat.
The heart will beat approximately 54 million (5.4×107) times before birth and over 3.2 billion (3.2×109) times over the course of an 80-year lifespan.[58]
Upper and lower limb development begins with the appearance of the limb buds by 4 weeks.[59]
The skin is transparent at this point because it is only one cell thick.
As the skin thickens, it will lose this transparency, which means that we will only be able to watch internal organs develop for about another month.[60]
Between 4 and 5 weeks, the brain continues its rapid growth and divides into five distinct sections.[61]
The head comprises about one-third of the embryo's total size.[62]
The cerebral (ser'ĕ-brăl) hemispheres appear,[63] gradually becoming the largest parts of the brain.[64]
Functions eventually controlled by the cerebral hemispheres include thought, learning, memory, speech, vision, hearing, voluntary movement, and problem-solving.[65]
ژور پیٹھٔ پٲنژن ہفتن منز چھ دمٲغ تیزی سٲن بڑان تہ چُھس پٲنژن نمایاں حصن منز تقسیم گژھان
کلۂ چھ سٲری ایمبریوس تریم حصس برابر آسان
سرِ برٔمکٸ تھزر چھ نون نیرٲن تۂ وارہ وارہ چھ دماغکٔ بڑ حصۂ بنٲن
برونہۂکُن چھ سرٕ برٔمی کنٹرول کرٲن تمنٕ کامین یمن منز، سوچُن، ہیچھن یاداشت، بوُلُن، نظرہ ین، بوزہ تہٕ والنٹری حرکت خود مختیاری تہٕ کانہہ مسلہٕ حل کرُن شامل چُھ
[55]
Gasser, 1975, 30;
O’Rahilly and Müller, 2001, 80.
[56]
O’Rahilly and Müller, 2001, 81.
[57]
van Heeswijk et al., 1990, 153.
[58]
See Appendix A.
[59]
Gasser, 1975, 49 & 59;
O’Rahilly and Gardner, 1975, 11;
O’Rahilly and Müller, 1985, 148 & 151;
O’Rahilly and Müller, 1987, 143;
Streeter, 1945, 30;
Uhthoff, 1990, 7 & 141. [upper and lower limb buds: Carnegie Stages 12 & 13]
[60]
Moore and Persaud, 2003, 486;
O’Rahilly, 1957, 459;
O’Rahilly and Müller, 2001, 165. For information about the first-trimester, direct-imaging technique used in this program (called embryoscopy), see Cullen et al., 1990.
[61]
O’Rahilly and Müller, 1999a, 134;
Sadler, 2005, 106. [Carnegie Stage 15]
[62]
Laffont, 1982, 5.
[63]
Bartelmez and Dekaban, 1962, 25;
Campbell, 2004, 17;
O’Rahilly and Gardner, 1979, 130;
O’Rahilly et al., 1984, 249;
O’Rahilly and Müller, 1999a, 115;
van Dongen and Goudie, 1980, 193. [Carnegie Stage 14]
[64]
Moore, 1980, 938.
[65]
Guyton and Hall, 2000, 663-677.
Page 7
In the respiratory system, the right and left main stem bronchi (brong'kī) are present[66] and will eventually connect the trachea (trā´kē-ă), or windpipe, with the lungs.
Note the massive liver filling the abdomen adjacent to the beating heart.
The permanent kidneys appear by 5 weeks.[67]
The yolk sac contains early reproductive cells called germ cells. By 5 weeks these germ cells migrate to the reproductive organs adjacent to the kidneys.[68]
[66]
Moore and Persaud, 2003, 245;
O’Rahilly and Boyden, 1973, 239;
O’Rahilly and Müller, 2001, 291;
Sparrow et al., 1999, 550.
[67]
Angtuaco et al., 1999, 13;
Lipschutz, 1998, 384; Moore and Persaud, 2003, 288;
O’Rahilly and Müller, 1987, 167 & 182;
O’Rahilly and Müller, 2001, 301;
Sadler, 2005, 72. [Carnegie Stage 14]
[68]
O’Rahilly and Müller, 2001, 23;
Waters and Trainer, 1996, 16;
Witschi, 1948, 70, 77 & 79.
[69]
O’Rahilly and Müller, 1987, 175;
Streeter, 1948, 139. [Carnegie Stage 15 ]
[70]
O’Rahilly and Gardner, 1975, 4. [Carnegie Stages 16 and 17 ]
Page 8
By 6 weeks the cerebral hemispheres are growing disproportionately faster than other sections of the brain.
The embryo begins to make spontaneous and reflexive movements.[71] Such movement is necessary to promote normal neuromuscular development.
A touch to the mouth area causes the embryo to reflexively withdraw its head.[72]
شيےٕ ہفتۂ پتۓ چُھ سرِ برم بڑٲن دماغ کيوبٲقی حصو کھوتۂ زياديہٕ پہنٔ
وونی چُھ ايمبريو پانۓ، بيہٕ کُنہ وجہ ورايیٕ حرکت باوٲن يژھ حرکتٔ چھ ضروری Neuromuscular بڑنۂ خٲطرہ۔
آسس سيتٕ اکہٕ لٹہ رلُن چُھ پانیٕ پانۓ کلۂ والسٕ تنس پيٹھ مايلٔ کران
The diaphragm (dī'ă-fram), the primary muscle used in breathing, is largely formed by 6 weeks.[75]
A portion of the intestine now protrudes temporarily into the umbilical cord. This normal process, called physiologic herniation (fiz-ē-ō-loj'ik her-nē-ā'shŭn), makes room for other developing organs in the abdomen.[76]
چھاتی ہُند پردہ ۔ يُس شہہ ہنس منز بنيادی ريشہ چُھ آسان۔ چُھ زيادہ پہن شين ہفتن اندر بنٲن
ٲندرمکھ اکھ حصہ چھ عارضی پاٹھی نيبر ہیوٲن نيرٔون ٲکس (Umbilical Cord) ٹيوبس منز یيہ عمل پتہٕ Physiological heriniation ونٲن چُہ۔ چُھ شمکس منز باقی انگن ہندس بننسٔ جاۓ پراوان۔
[71]
Birnholz et al., 1978, 539;
de Vries et al., 1982, 301 & 304: “The first movements were observed at 7.5 weeks postmenstrual age.“ [or 5½ weeks postfertilization age];
Humphrey, 1964, 99: earliest reflex 5½ weeks;
Humphrey, 1970, 12;
Humphrey and Hooker, 1959, 76;
Humphrey and Hooker, 1961, 147;
Kurjak and Chervenak, 1994, 48;
Visser et al., 1992, 175-176: “Endogenously generated fetal movements can first be observed after 7 weeks postmenstrual age (i.e. 5 weeks after conception);“
Natsuyama, 1991, 13;
O’Rahilly and Müller, 1999a, 336: 5½ weeks postfertilization;
Sorokin and Dierker, 1982, 723 & 726;
Visser et al., 1992, 175-176;
Natsuyama, 1991, 13: Spontaneous movement observed by “Carnegie stage 15“ (about 33 days postfertilization);
Hogg, 1941, 373: Reflex activity begins at 6½ weeks [adjusted to postfertilization age].
[72]
Goodlin, 1979, D-128.
[73]
Karmody and Annino, 1995, 251;
O’Rahilly and Müller, 2001, 480;
Streeter, 1948, 190.
[74]
Kurjak and Chervenak, 1994, 19.
[75]
de Vries et al., 1982, 320.
[76]
Gilbert-Barness and Debich-Spicer, 1997, 774;
Grand et al., 1976, 798;
O’Rahilly and Müller, 1987, 213;
Sadler, 2005, 66;
Spencer, 1960, 9;
Timor-Tritsch et al., 1990, 287.
[77]
O’Rahilly and Müller, 1987, 202-203.
[78]
Borkowski and Bernstine, 1955, 363 (cited by Bernstine, 1961, 63 & 66;
O’Rahilly and Müller, 1999a, 195;
van Dongen and Goudie, 1980, 193.);
Hamlin, 1964, 113. For a summary of in utero fetal encephalography (measuring brainwaves) in the near- term fetus using abdominal and vaginal electrodes see Bernstine et al., 1955.
Page 9
Nipples appear along the sides of the trunk shortly before reaching their final location on the front of the chest.[79]
[79]
O’Rahilly and Müller, 1985, 155: “The nipple appears at stages 17 and 18.“ [41-44 days postfertilization];
Wells, 1954, 126.
[80]
O’Rahilly and Müller, 2001, 221;
Streeter, 1948, 187.
[81]
Carlson, 2004, 189;
O’Rahilly and Gardner, 1972, 293;
O’Rahilly and Gardner, 1975, 19;
O’Rahilly and Müller, 2001, 385;
Sperber, 1989, 122 & 147. [Carnegie Stage 19]
[82]
de Vries et al., 1982, 305 & 311;
Visser et al., 1992, 176.
[83]
de Vries et al., 1988, 96;
Visser et al., 1992, 176.
[84]
Cooper and O’Rahilly, 1971, 292;
James, 1970, 214; Jordaan, 1979, 214;
Streeter, 1948, 192;
Vernall, 1962, 23: “The four chambers of the heart and the associated major vessels are externally apparent in a close approximation to their adult positions.“ [Carnegie Stage 18]
[85]
van Heeswijk et al., 1990, 153.
[86]
Straus et al., 1961, 446 (cited by Gardner and O’Rahilly, 1976, 571.): “…an electrocardiogram with the classical P, QRS, and T configuration has been obtained from a 23mm human embryo (Straus, Walker, and Cohen, 1961).“
[87]
O’Rahilly and Müller, 2001, 320. [Carnegie Stage 20]
[88]
Andersen et al., 1965, 646;
O’Rahilly, 1966, 35;
O’Rahilly and Müller, 1987, 259;
Pearson, 1980, 39;
Streeter, 1951, 193. [Carnegie Stage 22] Pigment within the retina is present from about 37 days postfertilization per O’Rahilly, 1966, 25. [Carnegie Stage 16]
[89]
Streeter, 1951, 191;
reiterated by O’Rahilly and Müller, 1987, 257.
[90] O’Rahilly and Gardner, 1975, 11;
O’Rahilly and Müller, 1987, 262.
Page 10
By 8 weeks, 75 percent of embryos exhibit right-hand dominance. The remainder is equally divided between left-handed dominance and no preference. This is the earliest evidence of right- or left-handed behavior.[93]
Pediatric textbooks describe the ability to "roll over" as appearing 10 to 20 weeks after birth.[94] However, this impressive coordination is displayed much earlier in the low-gravity environment of the fluid-filled amniotic sac.[95] Only the lack of strength required to overcome the higher gravitational force outside the uterus prevents newborns from rolling over.[96]
The embryo is becoming more physically active during this time.
Motions may be slow or rapid, single or repetitive, spontaneous or reflexive.
Head rotation, neck extension, and hand-to-face contact occur more often.[97]
Touching the embryo elicits squinting, jaw movement, grasping motions, and toe pointing.[98]
بچن ہنز نصابی کتاب چُھ باوان زِچکر لگُن (Roll Over) چُھ ظاہر گژھان زينہٕ پتہٕ 10 يا 20 ہفتہٕ بہرحالٕ يہٕ متاثر کرُن وۄل ربطہ چُھ نون گژھان کم کشش وإلس آبۂ سيت برٔتھ Amnolic Sac منز ضروری قوت رنہ آسنہ موکھ زيٲدہ زمينی کششہٕ ہُند مقابلہٕ کرنۂ کُنی يُس بچہ دٲنہٕ نيبر آسان چُھ۔ ۔ بچہٕ چھنہ ہکان دُبہ پھيرتھٕ
ايمبريو چُھ جسمانی طور زيادہ چُست آسان۔ اتھ وقتس منز
حرکتہٕ ہيکُن لوژہ تہٕ تيز آستھٕ اکۓ ياوارارہےٕلٹہٕ خودبخود يانيبرٔيم کُنہ وجہٕ کنی
کلوکٔ چکر، گردنہٕ ہُند پھلاوتہٕ اتہٕ پيٹھ بوتھس، سيت رلُن۔ چُھ واراہے لٹہ گژٲن
ايمبريوہس زِير کرنہ سيت چھ آچھ دولہٕ پھيرٲن دندہ ؤٹھی چھٕ حرکت کرٲن حرکتہٕ رٹھان۔ تہٕ کھور پنجہٕ اکسی طرفسٔ اشارہ کرٲن
Between 7 and 8 weeks, the upper and lower eyelids rapidly grow over the eyes and partially fuse together.[99]
Although there is no air in the uterus, the embryo displays intermittent breathing motions by 8 weeks.[100]
By this time, kidneys produce urine which is released into the amniotic fluid.[101]
In male embryos, the developing testes begin to produce and release testosterone (tes-tos´tĕ-rōn).[102]
Eight weeks marks the end of the embryonic period.
During this time, the human embryo has grown from a single cell into the nearly 1 billion (109) cells[106] which form over 4,000 (4×103) distinct anatomic structures.
The embryo now possesses more than 90 percent of the structures found in adults.[107]
[91]
O’Rahilly and Müller, 1999a, 288: “The brain at [Carnegie] Stage 23 is far more advanced morphologically than is generally appreciated, to such an extent that functional considerations are imperative.“
[92]
Jordaan, 1979, 149.
[93]
Hepper et al., 1998, 531;
McCartney and Hepper, 1999, 86.
[94]
Bates, 1987, 534.
[95]
de Vries et al., 1982, 320;
Goodlin and Lowe, 1974, 348;
Humphrey, 1970, 8.
[96]
Liley, 1972, 101.
[97]
de Vries et al., 1982, 311.
[98]
Humphrey, 1964, 102;
Humphrey, 1970, 19.
[99]
Process described by Andersen et al., 1965, 648-649;
O’Rahilly, 1966, 36-37;
O’Rahilly and Müller, 1987, 261. [Carnegie Stage 23]
[100]
Connors et al., 1989, 932;
de Vries et al., 1982, 311;
McCray, 1993, 579;
Visser et al.,1992, 177.
[101]
O’Rahilly and Müller, 2001, 304;
Windle, 1940, 118; (Windle reports urine formation begins at nine weeks.)
[102]
Moore and Persaud, 2003, 307;
Waters and Trainer, 1996, 16-17.
[103]
O’Rahilly and Gardner, 1975, 15: ”By the end of the embryonic proper (Stage 23, 8 postovulatory weeks), all of the major skeletal, articular, muscular, neural, and vascular elements of the limbs are present in a form and arrangement closely resembling those of the adult.“ See O’Rahilly,
1957, for a summary of joint types and a description of limb joint development during the embryonic period. See Gray et al., 1957, for a detailed examination of the bones and joints of the hand throughout the embryonic and fetal periods.
[104]
Hogg, 1941, 407;
Pringle, 1988, 178.
[105]
Hogg, 1941, 387;
O’Rahilly and Müller, 2001, 169.
[106]
Pringle, 1988, 176.
[107]
O’Rahilly and Müller, 2001, 87: “It has been estimated that more than 90% of the more than 4500 named structures of
the adult body become apparent during the embryonic period (O’Rahilly).“
Page 11
The fetal period continues until birth.
By 9 weeks, thumb sucking begins[108] and the fetus can swallow amniotic fluid.[109]
The fetus can also grasp an object,[110] move the head forward and back, open and close the jaw, move the tongue, sigh,[111] and stretch.[112]
Nerve receptors in the face, the palms of the hands, and the soles of the feet can sense light touch.[113]
"In response to a light touch on the sole of the foot," the fetus will bend the hip and knee and may curl the toes.[114]
The eyelids are now completely closed.[115]
In the larynx, the appearance of vocal ligaments signals the onset of vocal cord development.[116]
In female fetuses, the uterus is identifiable[117] and immature reproductive cells called oogonia (ō-ō-gō′nē-ă) are replicating within the ovary.[118]
External genitalia begin to distinguish themselves as either male or female.[119]
فيٹل پيريڈ (Fetal Period) چُھ زينس تام جاری روزان
نوہہٕ ہفتہ چُھ نيوٹھ ژشن شروع گژھان۔ تہٕ Fetus چُھ نينگلٲوان Amniotic Fluid
فيٹس چُھ کُنہ چيزس رٹتھ تہٕ ہيکان، کلہ برونہہٕ ياپتھٔ ہکان پھيرتھٕ دندہ وٹی مژرٲوتھ يابند کرتھ، ديويلہ ناوتھ، وش تراوتھ تہٕ وٲش کڈتھ ہيکان،
بوتھکی تہ ٲتھن ہُند Nerve Receptors تہٕ کھورن ہُند تلہ پتی چُھ گاشيچ زير محسوس کرٔتھ ۔
تلہٕ پتس پيٹھ گاشکہٕ زير ہندس جوابس منز چُھ ۔ Fetus مندلس تہٕ کوٹھسٔ تہ پنجن ہول کران۔
ٲچھ ٹٲر (Eye lids) چُھ وۄنی پورہ پٲٹھی بند روزان۔
ہٹس منز (Lyrinx) چُھ آوازٕہ ہُندLigments ننہ گژھنہ سيتی۔ يہٕ اشٲرہ ميلانٕز آواز ہُندCord چُھ بڑان۔
زنانہٕ حمل منز چُھ بچہ دانی نون نيرٲن۔ تہٕ نٲمکمل پيداواری سيلہٕ يمن Oogonia ونٲن چُھ ۔ چُھ اوری منز پانس ہيوی سيلہ بناوٲن
نيبريمGenitalia چُھ ہيوان فرق ننی کرٔنی۔ نرچھٲ کنہ مادہ۔
A burst of growth between 9 and 10 weeks increases body weight by over 75 percent.[120]
By 10 weeks, stimulation of the upper eyelid causes a downward rolling of the eye.[121]
The fetus yawns and often opens and closes the mouth.[122]
Most fetuses suck the right thumb.[123]
Sections of intestine within the umbilical cord are returning to the abdominal cavity.[124]
Ossification is underway in most bones.[125]
Fingernails and toenails begin to develop.[126]
Unique fingerprints appear 10 weeks after fertilization. These patterns can be used for identification throughout life.[127]
نون تہ دہنٔ ہفتين منز چُھ وُسجارزيٲدہ تيز آسان۔ جسمکو وزن چُھ 75 فی صد بڑٲن
دہمہ ہفتہ چُھ ہرٔم ٲچھ ٹٲرٕ Stimulation سيئت بونٴ کُن ہيوان وژنٔ
Fetus چُھ زٲمنہ کرٲن تہٕ وٲرہ لٹہ ٲچھ مژراوٲن تہٕ ٹوٲن۔
وارہ Fetus چُھ وُچھن نيوٹھ ژہان۔
اندرمن ہند حصہ يمٴ Umbilical Cord منز آسان چُھ ۔ ہيوان شکمس منز واپس گژن۔
ٲڈجہ چُھ قوت رٹٲن۔
اُونگجن ہندنم چھ بنان۔
فرٹيلائيزيشن پتہٕ دہٕ ہفتہ چُھ Finger Prints ننی نيران يم ہيکن سارسی زندگی پرزناونہ خاطرہ استعمال کرتھ ۔
By 11 weeks the nose and lips are completely formed.[128] As with every other body part, their appearance will change at each stage of the human life cycle.
The intestine starts to absorb glucose and water swallowed by the fetus.[129]
Though sex is determined at fertilization, external genitalia can now be distinguished as male or female.[130]
کہمہ ہفتۂ۔ نس تہ ووٹھ چُھ پورہ پٳٹھی بنٲن يم تہٕ گژن باقی جسم کين حصن ہندی پٲٹھی۔ پرتھ موقس پيٹھ تبديل گژتھ ۔ انسانی زندگی ہندس چکرس منز
ٲندريم چُھ آب تۂگلوکوزژشُن ہيوٲنا يس Fetus ننگلاوان چُھ ۔
يُدوے جنس بنانٔچُھ ۔ Fertilization وقتيے نيبرمن Genitilia ہيکووونی فرق کرتھ ۔ مرد يا زنانہ ہُند ۔
[108]
Liley, 1972, 103.
[109]
Campbell, 2004, 24;
de Vries, 1982, 311;
Petrikovsky et al., 1995, 605.
[110]
Robinson and Tizard, 1966, 52;
Valman and Pearson, 1980, 234.
[111]
de Vries et al., 1982, 305-307.
[112]
de Vries et al., 1982, 311.
[113]
Humphrey, 1964, 96;
Humphrey, 1970, 16-17 (cited by Reinis and Goldman,
1980, 232);
Humphrey and Hooker, 1959, 77-78.
[114]
Robinson and Tizard, 1966, 52;
Quote from Valman and Pearson, 1980, 234.
[115]
Andersen et al., 1965, 648-649;
O’Rahilly and Müller, 2001,
465; Pearson, 1980, 39-41.
[116]
O’Rahilly and Müller, 1984, 425. See also Campbell, 2004, 29.
[117]
O’Rahilly, 1977a, 128;
O’Rahilly, 1977b, 53;
O’Rahilly and Müller, 2001, 327.
[118]
O’Rahilly and Müller, 2001, 25 & 322.
[119]
Campbell, 2004, 28 & 35;
O’Rahilly and Müller, 2001, 336.
[120]
Brenner et al., 1976, 561.
[121]
Goodlin, 1979, D-128;
Humphrey, 1964, 102.
[122]
de Vries et al., 1982, 309.
[123]
Hepper et al., 1991, 1109.
[124]
Grand et al., 1976, 798;
Pringle, 1988, 178;
Sadler, 2005, 66;
Spencer, 1960, 9. [Pringle reports the bowel returns into the abdomen during the ninth or tenth week.]
[125]
Cunningham et al., 2001, 133.
[126]
O’Rahilly and Müller, 2001, 170-171.
[127]
Babler, 1991, 95;
Penrose and Ohara, 1973, 201;
For an overview of ridge formation in the skin of the hands see Cummins, 1929.
[128]
Timor-Tritsch et al., 1990, 291.
[129]
Koldovský et al., 1965, 186.
[130]
O’Rahilly and Müller, 2001, 336;
Wilson, 1926, 29.
Page 12
Between 11 and 12 weeks, fetal weight increases nearly 60 percent.[131]
Twelve weeks marks the end of the first third, or trimester, of pregnancy.
Distinct taste buds now cover the inside of the mouth. By birth, taste buds will remain only on the tongue and roof of the mouth.[132]
Bowel movements begin as early as 12 weeks and continue for about 6 weeks.[133]
The material first expelled from the fetal and newborn colon is called meconium (mĭ-kō'nē-ŭm).[134] It is composed of digestive enzymes, proteins, and dead cells shed by the digestive tract.[135]
By 12 weeks, upper limb length has nearly reached its final proportion to body size. The lower limbs take longer to attain their ultimate proportions.[136]
With the exception of the back and the top of the head, the body of the entire fetus now responds to light touch.[137]
Sex-dependent developmental differences appear for the first time. For instance, female fetuses exhibit jaw movement more frequently than males.[138]
In contrast to the withdrawal response seen earlier, stimulation near the mouth now evokes a turning toward the stimulus and an opening of the mouth.[139] This response is called the "rooting reflex" and it persists after birth, helping the newborn find his or her mother's nipple during breastfeeding.[140]
The face continues to mature as fat deposits begin to fill out the cheeks[141] and tooth development begins.[142]
By 15 weeks, blood-forming stem cells arrive and multiply in the bone marrow. Most blood cell formation will occur here.[143]
Although movement begins in the 6-week embryo, a pregnant woman first senses fetal movement between 14 and 18 weeks.[144] Traditionally, this event has been called quickening.[145]
کٲہن تۂ باہنٔ ہفتن منز باگٔ Fetal وزن چُھ 60 فی صدی بڑان۔
باہ ہفتہ چُھ گوڑنيوکھ ترين حصن ہُند اند آسان يا حمل لگنوکٔ Trimestar
ننی مزہ چشمہ چُھ آسکس ٲندر مسٔ حصس کور کرٲن۔ زينہ پتہٕ چُھ مزہ چشمہٕ روزٲن صرف زيوہ تہ آسکس چُھتس پيٹھٕ
Bowel Movements چُھ باہ ہفتۂ برونہہ شرو گژھان۔ تہٕ روزان چُھ شين ہفتنٕ تٲم۔
يُس مادہ گوڈہ چُھ Fetal تہٕ نور آمتہٕ کولانہٕ منز کڈٲن۔ تتھٕ چھ ونٲن Meconium يہ چُھ بنان ہاضمہٕ کررسہ سيت۔ پروٹين تہٕ مردہ سيلہٕ يمٕ ہاضمہ نالہٕ چُھ تراومتھ آسان۔
بٲہمہ ہفتہٕ چُھ نرن ہُندزيچھرواتان جسمکہٕ سائیز مطابق۔ يمنٔ زنگن چُھ زيٲدہ وکھ لگٲن۔ پورہ زيچھر رٹنس منز۔
کمرتہٕ کلہٕ کہ ہرمہ حصہ وارٔی چُھ ۔ سوری Fetus چھ روشنی ہنز زير محسوس کرٲن
جنس پيٹھ ورتھ بڑونی فرقہٕ چھ گوڈنکہ لٹہ ظاہر گژھان مثالےٕ زنٲنہٕ Fetus چُھ تاڑ کھنجين ہنز حرکت باوٲن مردِ سُندٕ کھوتہ زيادہ لٹہٕ
برونہہٕ يُس پتھ ہينوک Response وچھنہ آؤتتھ مقابل چُھ آسس نشٕStimulation چُھ وتلاوان اتھ Stimulus کُن پھيرُن تہٕ ٲس مژراوُن اتھ عملہ چُھ ونان Rooting Reflix يہ چھ زينۂ پتہٕ تہٕ روزٲن تہٕ چھ زينۂ ؤليئس بچس ماجہٕ ہُند ببہٕ ٹويئنڈ ژھارنس منز مدد کرٲن بيہٕسيتی دودھ چنہٕ وز
بُتھ چُھ وتلان۔ يام رخسارن پيٹھٕ چربی چھ کھسٲن تَہ دندن ہند بڑن چُھ شروع گژھان۔
پنداہ ہفتہٕ چُھ خون بنہٕ نچہٕ سيلہ واتٲن۔ تہٕ ٲڈجن ہنزوسہ منز چُھ تيدٲد بڑاوان ٲتہ نس چھ وارٔہ خون سيلہ بنٲن
يدوے حرکت چُھ شين ہفتن ہندس ايمبريوس منز شروع گژھٲن حاملہٕزنانہٕ چُھ گوڈہ Fetal Movement محسوس کرٲن ژوداہٕ پيٹھ ٲرداہٕ ہفتنٔ تٲم عٲم پٲٹھی چُھ اتھ Quickening ونان
[131]
Brenner, 1976, 561.
[132]
Lecanuet and Schaal, 1996, 3;
Miller, 1982, 169;
Mistretta and Bradley, 1975, 80.
[133]
Abramovich and Gray, 1982, 296;
Ramón y Cajal and Martinez, 2003, 154-155, report visualizing defecation (bowel movements) with ultrasound in utero in all 240 fetuses studied between 15 and 41 weeks [postmenstrual age].
[134]
O’Rahilly and Müller, 2001, 257;
For a description of meconium by Aristotle see Grand et al., 1976, 791.
[135]
Grand et al., 1976, 806.
[136]
Moore and Persaud, 2003, 105.
[137]
Lecanuet and Schaal, 1996, 2;
Reinis and Goldman, 1980, 232.
[138]
Hepper et al., 1997, 1820.
[139]
Mancia, 1981, 351.
[140]
Bates, 1979, 419.
[141]
Poissonnet et al., 1983, 7;
Poissonnet et al., 1984, 3: In a study of 488 fetuses, Poissonnet’s group found that adipose tissue (fat) appears in the face from 14 weeks postfertilization. By 15 weeks, fat appears in the abdominal wall, back, kidneys, and shoulders. By 16 weeks, fat is also present throughout the upper and lower limbs.
[142]
Pringle, 1988, 178. [Thirteenth week postfertilization]
[143]
Pringle, 1988, 179.
[144]
Sorokin and Dierker, 1982, 720;
Leader, 1995, 595: “Some pregnant women reported fetal flutters as early as 12 weeks (quickening).“ Women also tend to accurately
recognize fetal movement at earlier fetal ages during second and subsequent pregnancies as compared to first pregnancies.
[145]
Spraycar, 1995, 1479;
Timor-Tritsch et al., 1976, 70.
Page 13
By 16 weeks, procedures involving the insertion of a needle into the abdomen of the fetus trigger a hormonal stress response releasing noradrenalin, or norepinephrin (nor-ep'i-nef'rin), into the bloodstream.[146]
In the respiratory system, the bronchial tree is now nearly complete.[147]
A protective white substance, called vernix caseosa (ver'niks caseo'sa), now covers the fetus. Vernix protects the skin from the irritating effects of amniotic fluid.[148]
From 19 weeks fetal movement, breathing activity, and heart rate begin to follow daily cycles called circadian (ser-kā'dē-ăn) rhythms.[149]
شورا ہمہٕ ہفتہٕ سُہ طريقہ يتھ منز اژان چھ ۔ Fetus سندس شکمس منز سژن ہشنہ چھ وتش ديوٲن ہارمونن ہندس دباوس جواب ديتھ Noradrenaline يلہٕ تراونہٕ سيتی يا Norepinephocine خونہ چين رگنٔ منز نوی بچہٕ تہٕ جوان چُھ ہيوی ردعمل ہاوان۔ ہرگاہ تہندس جسمس منز کانہۂ آلہ آژہ
شہہٕ ہنکسٕ نظامس منز چُھ شہۂ رگن ہُند کُل چُھ الہ پلہ مکمل آسان
اکھ بچٲۄ کرن وۄل سيد مادہ يتھ Vernix Caseosa ونان چھ چھ fetus بچاوان۔ Vernix چھ مسلس بچاوان کھرونہ اثراتو نشہٕ يُس Aminiotic Fluid سيت گژھان چُھ ۔
کونوہيمٕ ہفتۂ پيٹھ چُھ Fetal حرکت تۂ شہۂ ہنچٕ کٲم تہٕ۔ دليچ حرکت چُھ روزانہ گردش کرٲن بتھ Circadrium rhythis ونان چھ ۔
By 20 weeks the cochlea, which is the organ of hearing, has reached adult size[150] within the fully developed inner ear. From now on, the fetus will respond to a growing range of sounds.[151]
Hair begins to grow on the scalp.
All skin layers and structures are present, including hair follicles and glands.[152]
By 21 to 22 weeks after fertilization, the lungs gain some ability to breathe air.[153] This is considered the age of viability because survival outside the womb becomes possible for some fetuses.[154]
وُہيمہٕ ہفتۂ چُھ Cochelea يس بوزنکٔ انگ ونٲن چُھ ۔ چُھ جوانسندس Sizes وٲتان پورہ بنے متس اندرٕمس کنس منز ٲتھ پيٹھ چُھ ۔ Fetus ردعمل ہاوٲن بڑوئين وارہن آوازنٔ
کلس پيٹھ چھ مس ہيوان يوُن
مُسلکس پيٹھ چھ مس ہيوانٕ يوُن يتھ منز مس مول تہٕ گو گجہ تۂ چھ
فرٹيلائيزيشن پتۂ 21 پيٹھ 22 ہفتن منز شوشس چھ شہۂ ہنچ قابليت بڑان يہٕ چھ۔ ۔۔۔۔۔ Viableيوان ماننہ تکيازہ شکمہ نيبر زندہ روزن چُھ کينژن بچن ہندٕہ باپت ممکن آسان دواہن ہندزيچھ کامٕ يابی چھ یژھ زندگی بچاونس ممکن بناوٲن يمٕ وقتہ برونہہ زيوان چُھ
[146]
Giannakoulopoulos et al., 1999, 494 & 498-499;
Glover and Fisk, 1999, 883;
Smith et al., 2000, 161. Cortisol levels also rise after invasive procedures following 21 weeks postfertilization - see Giannakoulopoulos et al., 1994, 80.
[147]
DiFiore and Wilson, 1994, 221-222;
Pringle, 1988, 178. [There is some disagreement among experts regarding when the bronchial tree is complete. Some say completion occurs as early as 16 weeks postfertilization while others say it occurs after birth.]
[148]
Campbell, 2004, 48;
Moore and Persaud, 2003, 107;
O’Rahilly and Müller, 2001, 168.
[149]
de Vries et al., 1987, 333;
Goodlin and Lowe, 1974, 349;
Okai et al., 1992, 391 & 396;
Romanini and Rizzo, 1995, 121;
For a description of the circadian system, see Rosenwasser, 2001, 127;
From Vitaterna et al., 2001, 92: Glossary: “Circadian: A term derived from the Latin phrase “circa diem,“ meaning “about a day;“ refers to biological variations or rhythms with a cycle of approximately 24 hours.“
[150]
Lecanuet and Schaal, 1996, 5-6;
Querleu et al., 1989, 410.
[151]
Glover and Fisk, 1999, 882;
Hepper and Shahidullah, 1994, F81;
Querleu et al., 1989, 410;
Sorokin and Dierker, 1982, 725 & 730;
Valman and Pearson, 1980, 233-234.
[152]
Pringle, 1988, 180.
[153]
Hansen and Corbet, 1998, 542.
[154]
O’Rahilly and Müller, 2001, 92, report the age of viability as 20 weeks postfertilization; Draper et al., 1999, 1094, report a survival rate of 2% at 20 weeks postfertilization, 6% at 21 weeks, and 16% at 22 weeks. Moore
and Persaud, 2003, 103, report viability at 22 weeks;
Wood et al., 2000, 379, report survival rates of 11% at 21 weeks, 26% at 22 weeks and 44% at 23 weeks (postfertilization weeks) based on premature birth data from the United Kingdom during 1995. Cooper et al. 1998, 976, (Figure 2) report infants with a birth weight over 500 grams experienced survival rates (all approximate) of 28% at 21 weeks postfertilization, 50% at 22 weeks, 67% at 23 weeks, and 77% at 24 weeks. Draper et al., 2003, updated their previously published survival tables for premature infants and now report an overall survival rate of 7% at 20 weeks, 15% at 21 weeks, 29% at 22 weeks, 47% at 23 weeks and 65% at 24 weeks. [All ages corrected to reflect postfertilization age.] These survival tables are available online at http://bmj.bmjjournals.com/cgi/content/full/319/7217/1093/DC1. Their methodology is described in their earlier paper (Draper et al., 1999, 1093-1094.) Note: These published survival tables reflect postmenstrual ages. Hoekstra et al., 2004, e3, report a survival rate of 66% at 23 weeks and 81% at 24 weeks “gestational age“ [not specifically defined] for premature births from 1996 to 2000 at their center in Minneapolis, Minnesota.
Page 14
By 24 weeks the eyelids reopen[155] and the fetus exhibits a blink-startle response.[156] This reaction to sudden, loud noises typically develops earlier in the female fetus.[157]
Several investigators report exposure to loud noise may adversely affect fetal health. Immediate consequences include prolonged increased heart rate, excessive fetal swallowing, and abrupt behavioral changes.[158] Possible long-term consequences include hearing loss.[159]
The fetal respiratory rate can rise as high as 44 inhalation-exhalation cycles per minute.[160]
During the third trimester of pregnancy, rapid brain growth consumes more than 50 percent of the energy used by the fetus. Brain weight increases between 400 and 500 percent.[161]
By 26 weeks the eyes produce tears.[162]
The pupils respond to light as early as 27 weeks.[163] This response regulates the amount of light reaching the retina[164] throughout life.
All components required for a functioning sense of smell are operational. Studies of premature babies reveal the ability to detect odors as early as 26 weeks after fertilization.[165]
Placing a sweet substance in the amniotic fluid increases the rate of fetal swallowing. In contrast, decreased fetal swallowing follows the introduction of a bitter substance. Altered facial expressions often follow.[166]
Through a series of step-like leg motions similar to walking, the fetus performs somersaults.[167]
The fetus appears less wrinkled as additional fat deposits form beneath the skin.[168] Fat plays a vital role in maintaining body temperature and storing energy after birth.
ژوہو ہفتہ گژھتہ چُھ ٲچھ ٹٲری بيہ مژاونہ يوان تہٕ Fetus چُھ ہاوان ٹٲرِتُل نک ردِعمل اچانک تہٕ تيز آوازٕ پيٹھ ردعمل چھ زنانہ Fetus منز برونہہ پيدہ گژھان
وارۂ تحقيق کرن والی چُھ ونٲن زِتيزٕ آواز۔ چھ ہيکان بڑہ ونس بچس راوۂ ناکارۂ اثر کرٲن نزديک نتيجہ چُھ ۔ ژير تام روزن واجُن دليچ دبراۓ بنن وۄل بچہ زيادہ ننگلاوان تۂ يکدم چُھ ہاوان ورتاوس منز تبديلی زيٹھ وقتکينٕ نتچن منز چُھ بوزنُک قوت ضایع سُپدن
Fetal شہۂ ہيکہ تيوتٕ بڑتھ زٕٲکس منٹس منز ہييہٕتہٕ تراوہ 44 لٹہٕ شہۂ
حملکس تريمس حصس منز چُھ دماغچ تيز بڑون تماقو تک 50% خرچاوان۔ يُس Fetus استعمال چُھ کرٲن دماغکُ وزن چُھ 400% پيٹھ 500% ہُران
شتوہمس ہفتس منز چُھ اوشُ پيدہ گژھان۔
ستُووہمہ ہفتہٕ برونی چُھ اچھن ہُند Pupil گاشک ردعمل ہاوان۔ يہ ردعمل چھ روشنی ہُند تعداد باقاعدہ بناوان چُھ يُس Retina پيٹھ سارسی زندگی واتان چُھ ۔
ساری ضروری جُزيم مشک ہنس منز بکار چھ يوان چھ بنان کٲم کرنس لائيق برونہی زنہ والين بچن متعلق معلومات چھ ہاوان زمُشک ہينک حس چُھ بدہ نيران۔ فرٹيلائيزيشن پتہٕ شتوہہ ہفتہ پتۓ
Aminiotic Fluid منز اکھ مزہ دار مادہ آسنہ سيت چُھ ۔ فيٹسس منز ننگلاونُک قوت ہُران اتھ مقابلہ چُھ Fetus کم ننگلاوان ژُوکی مادہ اندر گژنہ سيت۔ تبديل گژون بوتھکی تاثرات چُھ اکثرامہٕ پتہٕ گژان
مسلسل قدم تُلنکہ زنگہ ہُند حرکژ سيت۔ يُس پکنکُ ہيو چُھ آسان Fetus چھ لرہ پھيرٲن۔
Fetus چُھ کم گنہٕ وٲلی بٲسان۔ تکيازہٕ علاوہ چربی چُھ مسلس تلٕ جمع گژان چربی چھ جسمانی حرارت برقرار تھاونس منز مدد کرٲن تہٕ زينہٕ پتۂ قوت جمع کرتھ تھاوان
[155]
Open eyes are visualized by 4D ultrasound following 22 weeks postfertilization per Campbell 2002, 3; De Lia, 2002, personal communication;
O’Rahilly and Müller, 2001, 465. For a detailed ultrastructural study of the union between the upper and lower eyelids see Andersen et al., 1967, 293.
[156]
Birnholz and Benacerraf, 1983, 517 (cited by Drife, 1985, 778);
See also Campbell, 2002, 3: Professor Stuart Campbell correctly points out that the eyes of the fetus are closed most of the time and a true blink requires the eyes to be open. Perhaps the “blink-startle“ response would be more accurately termed “squint-startle.“
[157]
Lecanuet and Schaal, 1996, 9.
[158]
Visser et al., 1989, 285.
[159]
Gerhardt, 1990, 299;
Petrikovsky et al., 1993, 548-549;
Pierson, 1996, 21 & 26.
[160]
Natale et al., 1988, 317.
[161]
Growth of the human brain, 1975, 6;
Mancuso and Palla, 1996, 290.
[162]
Isenberg et al., 1998, 773-774.
[163]
Robinson and Tizard, 1966, 52.
[164]
Noback et al., 1996, 263.
[165]
Lecanuet and Schaal, 1996, 3.
[166]
Lecanuet and Schaal, 1996, 3;
Liley, 1972, 102;
Moore and Persaud, 2003, 219;
Reinis and Goldman, 1980, 227.
[167]
Liley, 1972, 100.
[168]
England, 1983, 29.
Page 15
By 28 weeks the fetus can distinguish between high- and low-pitched sounds.[169]
By 30 weeks, breathing movements are more common and occur 30 to 40 percent of the time in an average fetus.[170]
During the last 4 months of pregnancy, the fetus displays periods of coordinated activity punctuated by periods of rest. These behavioral states reflect the ever-increasing complexity of the central nervous system.[171]
Fetus چُھ ہيکان فرق محسوس کرتھٕ تيزتہٕ لوژ آواز ہُند
تريمہٕ ہفتہ چُھ شہۂ ہنچۂ حرکتہٕ زيادہ عام آسان تۂ يوان چھ 30 پيٹھ 40% عام Fetus منز۔
حملکسٕ آخری ژورمين ريتن منز۔ Fetus چُھ باؤان رلتھ ميلتھ حرکاتن ہُند وکھ ۔ ٕيمن منز آرام کرنہٕ خاطر وکھ چُھ ميلان۔ يم ورتاؤ چھ باوٲن وارٲہ بڑے مژ Complexity مرکزی اعصابی نظامکی
By approximately 32 weeks, true alveoli (al-vē'ō-lī), or air "pocket" cells, begin developing in the lungs. They will continue to form until 8 years after birth.[172]
At 35 weeks the fetus has a firm hand grasp.[173]
Fetal exposure to various substances appears to affect flavor preferences after birth. For instance, fetuses whose mothers consumed anise, a substance which gives licorice its taste, showed a preference for anise after birth. Newborns without fetal exposure disliked anise.[174]
الہ پلۂ دوٕترہمس ہفتسٔ منز ٕچھ ہوا تھيلہٕ يا ہوا سيلن ہُند چندہ چُھ ہيوان شوشس منز بڑنی يم چھ زينہ پتہ آٹھن ريتن تام بڑان۔
پانژترہميسٔ ہفتس منز چُھ اتھن ہنز تھپ کرنگی طاقت بڑان۔
وارہن مادن سيت فيٹس رلنہ سيت چُھ زينہ پتہٕ مُشککی ترجی حاتن پيٹھ اثر پيوان۔ مثالے تم بچہٕ ہنزٕ ماجہٕAnise استعمال چُھ کران اکھ سُھ مادہ يُس مٹرس مزہ چُھ ديوان چُھ باوان زينہ پتہٕ Anise متعلق ترجيحات۔ نوزينہ والی چُھ Anise ناپسند کران يمن نہٕ اتھ سيت واٹھ چُھ پيوان۔
The fetus initiates labor[175] by releasing large amounts of a hormone called estrogen (es´trō-jen)[176] and thus begins the transition from fetus to newborn.
Labor is marked by powerful contractions of the uterus, resulting in childbirth.[177]
From fertilization to birth and beyond, human development is dynamic, continuous, and complex. New discoveries about this fascinating process increasingly show the vital impact of fetal development on lifelong health.
As our understanding of early human development advances, so too will our ability to enhance health––both before and after birth.
Fetus چُھ محنت شروع کران۔ زيادہ مقدارسٔ منز Estrogen ہارمون يلہٕ تراونۂ سيت يتھٔ پٲٹھی چھٕ تم Fetus پيٹھ نوزائيد بنان
بچہ دانی منز طاقتور ژومرن سيتی چُھ مشقت شروع گژھان۔ يم سيت بچہ چُھ ذيوان۔
فرٹيلائيزيشن پيٹھ ذينہٕ تام تۂ تمہٕ پتۂ انسانی ترقیٕ چھٕ متحرک مسلسلٕ تہٕ رلتھ ۔ اتھ پُرکشش عملہٕ متعلق ايجادات۔ چھ واراہ اہم اثرات Fetal Developments پيٹھ ہاوان صحتس پيٹھ سارسی وٲنسہٕ
يوتھ اس گوڈنکی انسانی ترقی سمجھتہ ہيکان چُھ ۔ تيوتھ ہيکو اُس صحت ٹھيک تھاونس منز قابليت حاصل کرتھ ۔ زينہٕ برونہہ تہٕ زينۂ پتہ تہٕ
[169]
Glover and Fisk, 1999, 882;
Hepper and Shahidullah, 1994, F81.
[170]
Connors et al., 1989, 932;
de Vries et al., 1985, 117;
Patrick et al., 1980, 26 & 28;
Visser et al., 1992, 178.
[171]
DiPietro et al., 2002, 2: “One of the hallmarks of development before birth is the coalescence of patterns of fetal and behavioral and cardiac function into behavioral states, which is widely viewed as reflective of the developing integration of the central nervous system.“
[172]
Lauria et al., 1995, 467.
[173]
Moore and Persaud, 2003, 108.
[174]
Schaal et al., 2000, 729.
[175]
Liley, 1972, 100.
[176]
Moore and Persaud, 2003, 131.
[177]
Cunningham et al., 2001, 252.
Page 16
Given:
1. The DNA molecule measures 3.4×10-9 meters per 10 base pairs.[178]
2. There are 3 billion (3×109) base pairs per cell.
3. There are an estimated 100 trillion (1014) cells per adult.
4. The distance from the earth to the sun is approximately 93 million miles.
5. There are 2.54 centimeters (cm) per inch.
Step 1 Compute the length of DNA in a single cell:
3.4×10-9 meters/10 base pairs × 3×109 base pairs/cell = 1.02 meters of DNA per cell
Step 2 Compute the total length of DNA in an adult’s 100 trillion cells:
1.02 meters of DNA/cell × 1014 cells = 1.02×1014 meters of DNA per adult*
Step 3 Convert 1.02×1014 meters to miles:
1.02×1014 meters × 100 cm/meter × 1inch/2.54 cm × 1 foot/12 inches × 1 mile/5,280 feet
= 6.3379×1010miles of DNA
Step 4 Compute how many round trips from the earth to the sun:
6.3379×1010 miles of DNA ÷ (93,000,000 miles/trip × 2 trips/round trip) =
Therefore, the DNA in a single adult, if oriented in linear fashion, would exceed 63 billion miles in length. This is long enough to extend from the earth to the sun and back––340 times.
* Approximately 25 trillion red blood cells are present in the adult.[179] It should be noted that red blood cells contain DNA early in their maturation phase but this DNA degenerates and is not present in the mature form. This calculation includes the DNA from red blood cells.
[178]
Lodish et al., 2000, 104.
[179]
Guyton and Hall, 2000, 2.
Page 17
The following page contains a list of 3,808 capital letters each of which represents a single base.
Given:
1. A, G, T, and C each represent a base within the DNA of a single cell.
2. Each line contains 68 letters without spaces representing 68 bases.
3. Each page contains 56 lines. (Page size: 8½ × 11 inches, font: Times New Roman, font size: 10, spaces between letters: none, lines: single spaced, margins: as shown)
4. Each cell contains 3 billion base pairs equaling 6 billion bases.
The calculation of the number of pages required to list all DNA bases in a single cell is as follows:
68 bases/line × 56 lines/page = 3,808 bases/page
6,000,000,000 bases/cell ÷ 3,808 bases/page = 1,575,630 pages/cell
Page 18
Given:
1. The placenta maintains embryonic and fetal temperature between 0.5 ºC and 1.5 ºC above maternal core temperature.[180]
2. Maternal core temperature is approximately 99.6º Fahrenheit.
3. The formula to convert temperature from Fahrenheit (ºF) to Celsius (ºC) is:
ºC = 5/9 (ºF - 32)
The calculation to compute the range of embryonic and fetal body temperature is as follows:
Step 1 Convert maternal core temperature to Celsius:
Maternal core temperature in ºC: ºC = 5/9 (99.6 - 32) = 37.56 ºC
Step 2 Compute lower and upper ranges of fetal body temperature in Celsius:
Lower range (Celsius) = maternal core temperature + 0.5 ºC = 37.56 + 0.5 = 38.2 ºC
Upper range (Celsius) = maternal core temperature + 1.5 ºC = 37.56 + 1.5 = 39.2 ºC
Step 3 Convert results to Fahrenheit:
ºC = 5/9 (ºF - 32) 9/5 ºC = (ºF - 32) ºF = 9/5 ºC + 32
Substituting to find the lower limit of fetal body temperature
ºF = 9/5 ºC + 32 ºF = 9/5 (38.16) + 32 ºF = 100.7º
Substituting to find the upper limit of fetal body temperature
ºF = 9/5 ºC + 32 ºF = 9/5 (39.16) + 32 ºF = 102.5º
Summary of Normal Embryonic and Fetal Body Temperature Range
ºF | ºC | |
---|---|---|
Lower Limit | 100.7 | 38.2 |
Upper Limit | 102.5 | 39.2 |
Page 19
The Embryonic Period
Various authors agree the heart rate peaks at 7 weeks. Reported heart rates vary however. Van Heeswijk et al. report a peak heart rate of 167 ± 8 beats per minute (bpm)[181] while Leeuwen et al. report a peak rate of 175 bpm.[182] Van Lith et al. report the median fetal heart rate peaks at 177 bpm at 7 weeks.[183] One hundred seventy (170) bpm has been chosen as the peak heart rate for illustration purposes in this calculation. The heart rate for the various weeks from 7 through 38 have been calculated via linear interpolations[184] assuming heart rates of 170 bpm at 7 weeks and 140 bpm at term or 38 weeks.[185]
(Note: Heart rates are estimated. Living conditions and individual experience can and will vary.)
The Fetal Period
Week # | Average Heart Rate (Beats per Minute) |
Beats per Week | Running Total |
---|---|---|---|
9 | 168.06 | 1,694,090 | 9,103,216 |
10 | 167.10 | 1,684,336 | 10,787,551 |
11 | 166.13 | 1,674,581 | 12,462,132 |
12 | 165.16 | 1,664,826 | 14,126,958 |
13 | 164.19 | 1,655,071 | 15,782,029 |
14 | 163.23 | 1,645,316 | 17,427,346 |
15 | 162.26 | 1,635,562 | 19,062,907 |
16 | 161.29 | 1,625,807 | 20,688,714 |
17 | 160.32 | 1,616,052 | 22,304,766 |
18 | 159.35 | 1,606,297 | 23,911,063 |
19 | 158.39 | 1,596,542 | 25,507,605 |
20 | 157.42 | 1,586,787 | 27,094,393 |
21 | 156.45 | 1,577,033 | 28,671,425 |
22 | 155.48 | 1,567,278 | 30,238,703 |
23 | 154.52 | 1,557,523 | 31,796,226 |
24 | 153.55 | 1,547,768 | 33,343,994 |
25 | 152.58 | 1,538,013 | 34,882,008 |
26 | 151.61 | 1,528,259 | 36,410,266 |
27 | 150.65 | 1,518,504 | 37,928,770 |
28 | 149.68 | 1,508,749 | 39,437,519 |
29 | 148.71 | 1,498,994 | 40,936,513 |
30 | 147.74 | 1,489,239 | 42,425,752 |
31 | 146.77 | 1,479,484 | 43,905,237 |
32 | 145.81 | 1,469,730 | 45,374,966 |
33 | 144.84 | 1,459,975 | 46,834,941 |
34 | 143.87 | 1,450,220 | 48,285,161 |
35 | 142.90 | 1,440,465 | 49,725,626 |
36 | 141.94 | 1,430,710 | 51,156,337 |
37 | 140.97 | 1,420,956 | 52,577,292 |
38 | 140.00 | 1,411,201 | 53,988,493 |
(Approximately 54 million beats before birth) |
Counting the Beats of a Lifetime
The Postnatal Period from Birth to 80 Years
Year # | Average Heart Rate (Beats per Minute)*[186] |
Beats per Year | Running Total |
---|---|---|---|
1 | 120 | 63,115,200 | 63,115,200 |
2 | 110 | 57,855,600 | 120,970,800 |
3 | 103 | 54,173,880 | 175,144,680 |
4 | 103 | 54,173,880 | 229,318,560 |
5 | 103 | 54,173,880 | 283,492,440 |
6 | 103 | 54,173,880 | 337,666,320 |
7 | 95 | 49,966,200 | 387,632,520 |
8 | 95 | 49,966,200 | 437,598,720 |
9 | 95 | 49,966,200 | 487,564,920 |
10 | 95 | 49,966,200 | 537,531,120 |
11 | 85 | 44,706,600 | 582,237,720 |
12 | 85 | 44,706,600 | 626,944,320 |
13 | 85 | 44,706,600 | 671,650,920 |
14 | 85 | 44,706,600 | 716,357,520 |
15 | 80 | 42,076,800 | 758,434,320 |
16 | 80 | 42,076,800 | 800,511,120 |
17 | 75 | 39,447,000 | 839,958,120 |
18 | 75 | 39,447,000 | 879,405,120 |
19 | 70 | 36,817,200 | 916,222,320 |
20 | 70 | 36,817,200 | 953,039,520 |
21-80 | 70 | 2,209,032,000 | 3,162,071,520 |
(Approximately 3.16 billion beats from birth to age 80 years) | |||
Estimated Total Heart Beats From the 3-Week Embryo to Age 80 Years |
3,216,060,000 | ||
(Approximately 3.2 Billion Beats Per Lifetime) |
[181]
van Heeswijk et al., 1990, 153.
[182]
Leeuwen et al., 1999, 265.
[183]
van Lith et al., 1992, 741.
[184]
See Appendix A.
[185]
DiPietro et al., 1996, 2559.
[186]
Age appropriate pediatric heart rates adapted from Bates, 1987, 541.
Page 20
O'Rahilly and Müller's Age Assignments vs. Carnegie Stages, 1987 to 2001
Carnegie Stage |
Number of Somites |
Greatest Length (mm) |
1987 Age [187] Convention (in PF Days*) |
1999 Age [188] Convention (in PF Days*) |
2001 Age [189] Convention (in PF Days*) |
---|---|---|---|---|---|
1 | 0.1 - 0.15 | 1 | - | 1 | |
2 | 0.1 - 0.2 | 1½ - 3 | 2 - 3 | 2 - 3 | |
3 | 0.1 - 0.2 | 4 | 4 - 5 | 4 - 5 | |
4 | 0.1 - 0.2 | 5 - 6 | 6 | 6 | |
5 | 0.1 - 0.2 | 7 - 12 | 7 - 12 | - | |
5a | 0.1 | 7 - 8 | - | 7 - 8 | |
5b | 0.1 | 9 | - | 9 | |
5c | 0.15 - 0.2 | 11 - 12 | - | 11 - 12 | |
6 | 0.2 | 13 | 17 | 17 | |
6a | - | - | - | - | |
6b | - | - | - | - | |
7 | 0.4 | 16 | 19 | 19 | |
8 | 1.0 - 1.5 | 18 | 23 | - | |
8a | - | - | - | 23 | |
8b | - | - | - | 23 | |
9 | 1-3 | 1.5 - 2.5 | 20 | 26 | 25 |
10 | 4-12 | 2 - 3.5 | 22 | 29 | 28 |
11 | 13-20 | 2.5 - 4.5 | 24 | 30 | 29 |
12 | 21-29 | 3 - 5 | 26 | 31 | 30 |
13 | 30+ | 4 - 6 | 28 | 32 | 32 |
14 | 5 - 7 | 32 | 33 | 33 | |
15 | 7 - 9 | 33 | 35 | 36 | |
16 | 8 - 11 | 37 | 37 | 38 | |
17 | 11 - 14 | 41 | 40 | 41 | |
18 | 13 - 17 | 44 | 42 | 44 | |
19 | 16 - 18 | 47½ | 44 | 46 | |
20 | 18 - 22 | 50½ | 47 | 49 | |
21 | 22 - 24 | 52 | 50 | 51 | |
22 | 23 - 28 | 54 | 52 | 53 | |
23 | 27 - 31 | 56½ | 56 | 56 |
* PF Days = Postfertilization Days
There is international agreement among embryologists that human development during the embryonic period be divided into 23 stages (which were initially proposed by Mall, described by Streeter, and amended by O'Rahilly and Müller in 1987).[190] These have come to be known as Carnegie Stages. Particular internal and external features are required for inclusion in any given embryonic stage. These stages are independent of age and length and the use of the term 'stage' should be reserved for reference to this system per O'Rahilly and Müller in multiple publications.
Along with nearly-universal acceptance of the human embryonic staging system, a variety of age assignments have been proposed for each embryonic stage. Streeter believed the embryonic period spanned a 47- to 48-day period instead of the 56-day period accepted today. The Endowment for Human Development adopts the convention set forth by O'Rahilly and Müller in 1987 which has received widespread, but not universal, acceptance. O'Rahilly and Müller have since proposed amending this convention in light of transvaginal ultrasound data through a personal communication with Dr. Josef Wisser in 1992.[191] These alternate proposals are provided for the interested reader.
For instance, the onset of embryonic cardiac contraction (onset of the heartbeat) has long been described as a Carnegie Stage 10 or possibly a late Stage 9 event.[192] We report this event occurring at an age of 3 weeks, 1 day (22 days) postfertilization using the 1987 convention. Others may report this occurrence at 28 or 29 days as shown above. Of interest is a paper by Wisser and Dirschedl who reported using transvaginal ultrasound to visualize the embryonic heartbeat 23 days postfertilization in two embryos fertilized in vitro “with exactly known … age” and “in embryos from 2 mm of greatest length onwards.”[193] This finding most closely coincides with the 1987 age convention. Schats et al. reported the earliest cardiac activity at 25 days after follicle aspiration in embryos conceived in vitro.[194] Tezuka et al. reported the earliest cardiac activity at 23 days postfertilization in embryos conceived naturally.[195]
There is considerable variation in normal human development during the postnatal period. The prenatal period is no different with variations in the size, rate of growth, and order of appearance of some structures or functions. No one knows the exact age range for each stage with absolute certainty. These approximations may change in the future as additional knowledge is gained through careful, published research.
[187]
O'Rahilly and Müller, 1987, 3. Greatest length data is essentially uniform throughout the various texts.
[188]
O'Rahilly and Müller, 1999a. Various pages.
[189]
O'Rahilly and Müller, 2001, 490. Table A-1 – essentially unchanged from the 1996 edition. The 2001 convention
differs only slightly from the 1999 convention as shown.
[190]
O'Rahilly and Müller, 2001, 3.
[191]
O'Rahilly and Müller, 1999a, 13.
[192]
See footnote #51.
[193]
Quotes from Wisser and Dirschedl, 1994, 108.
[194]
Schats et al., 1990, 989.
[195]
Tezuka, 1991, 211.
Page 21
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Journal Abbreviation | Journal Name |
---|---|
Acta Anat | Acta Anatomica |
Acta Opthalmol | Acta Ophthalmologica |
Adv Contracept | Advances in Contraception |
Alcohol Res Health | Alcohol Research & Health |
Am J Anat | The American Journal of Anatomy |
Am J Cardiol | The American Journal of Cardiology |
Am J Kidney Dis | American Journal of Kidney Diseases |
Am J Obstet Gynecol | American Journal of Obstetrics and Gynecology |
Am J Reprod Immunol | American Journal of Reproductive Immunology and Microbiology |
Am J Respir Cell Mol Biol | American Journal of Respiratory Cell and Molecular Biology |
Am J Roentgenol | American Journal of Roentgenology |
Anat Embryol | Anatomy and Embryology |
Ann Otol Rhinol Laryngol | The Annals of Otology, Rhinology, and Laryngology |
Ann R Coll Surg Eng | Annals of the Royal College of Surgeons of England |
Arch Dis Child | Archives of Disease in Childhood |
Arch Ophthalmol | Archives of Ophthalmology |
Aust N Z J Psychiatry | The Australian and New Zealand Journal of Psychiatry |
Biol Neonate | Biology of the Neonate |
Birth Defects Orig Artic Ser | Birth Defects Original Article Series |
Br J Obstet Gynaecol | British Journal of Obstetrics and Gynaecology |
Br Med Bull | British Medical Bulletin |
Br Med J | British Medical Journal |
Chem Senses | Chemical Senses |
Child Dev | Child Development |
Clin Obstet Gynecol | Clinical Obstetrics and Gynecology |
Contrib Embryol | Contributions to Embryology |
Dev Med Child Neurol | Developmental Medicine and Child Neurology |
Dev Pharmacol Ther | Developmental Pharmacology and Therapeutics |
Early Hum Dev | Early Human Development |
Eur J Obstet Gynecol Reprod Biol | European Journal of Obstetrics, Gynecology, and Reproductive Biology |
Eye | Eye |
Facial Plast Surg | Facial Plastic Surgery |
Fertil Steril | Fertility and Sterility |
Fetal Ther | Fetal Therapy |
Gastroenterology | Gastroenterology |
Gynecol Invest | Gynecologic Investigation |
Gynecol Obstet Invest | Gynecologic and Obstetric Investigation |
Int J Psychoanal | The International Journal of Psycho-Analysis |
Ir J Med Sci | Irish Journal of Medical Science |
J Clin Ultrasound | Journal of Clinical Ultrasound |
J Comp Neurol | The Journal of Comparative Neurology |
J Med Genet | Journal of Medical Genetics |
J Comp Neurol | Journal of Neuroradiology |
J Pathol Bacteriol | The Journal of Pathology and Bacteriology |
J Pediatr Surg | Journal of Pediatric Surgery |
J Perinat Med | Journal of Perinatal Medicine |
J Anat | Journal of Anatomy |
JAMA | JAMA : The Journal of the American Medical Association |
Lancet | Lancet |
N Engl J Med | The New England Journal of Medicine |
N Z Med J | New Zealand Medical Journal |
Nature | Nature |
Neurology | Neurology |
Neuropsychologia | Neuropsychologia |
Nutr Rev | Nutrition Reviews |
Obstet Gynecol | Obstetrics & Gynecology |
Pediatr Pathol Lab Med | Pediatric Pathology & Laboratory Medicine |
Pediatr Res | Pediatric Research |
Pediatrics | Pediatrics |
Physiol Rev | Physiological Reviews |
Science | Science |
Semin Pediatr Surg | Seminars in Pediatric Surgery |
Semin Perinatol | Seminars in Perinatology |
Semin Reprod Endocrinol | Seminars in Reproductive Endocrinology |
Semin Roentgenol | Seminars in Roentgenology |
Teratology | Teratology |
Trans Am Neurol Assoc | Transactions of the American Neurological Association |
Ultrasound Obstet Gynecol | Ultrasound in Obstetrics & Gynecology |
Z Anat Entwicklungsgesch | Zeitschrift fur Anatomie und Entwicklungsgeschichte |
Page 28
A |
Page Links |
abdomen | 8, 9, 14 |
abdominal | 6, 12 |
activity | 10, 14, 16 |
adenine | 4 |
adult(s) | 3, 4, 10, 11, 14 |
age | 14 |
age of viability | 14 |
air | 11, 14, 16 |
alveoli | 16 |
amnion | 6, 7 |
amniotic fluid | 7, 11, 12, 14, 15 |
anise | 16 |
articular | 11 |
B |
|
base pairs | 17 |
base(s) | 4, 18 |
behavior(al) | 11, 15, 16 |
billion | 4, 7, 11 |
birth | 3, 6, 7, 11, 12, 13, 15, 16 |
blastocyst | 5 |
blink-startle | 15 |
blood | 4, 5, 6, 7, 9, 11, 13 |
blood cells | 6 |
blood vessels | 6, 11 |
blueprint | 4 |
body | 3, 4, 5, 6, 11, 12, 13, 15 |
body plan | 6 |
bone(s) | 6, 10, 11, 12, 13 |
bowel | 13 |
brain | 6, 7, 9, 11, 15 |
breastfeeding | 13 |
breathing | 9, 11, 16 |
bronchi | 8 |
bronchial tree | 14 |
buds | 7, 13 |
C |
|
cardiac | 16, 21 |
cardiovascular | 6 |
Carnegie Stage(s) | 3, 4, 5, 6, 7, 8, 9, 10, 21 |
cartilage | 6, 8 |
cell(s) | 3, 4, 5, 6, 7, 8, 9, 11, 12, 13, 16 |
central nervous system | 16 |
cerebral hemispheres | 7, 9 |
chambers | 6, 7 |
cheeks | 13 |
chest | 6, 10 |
childbirth | 16 |
chromosomes | 4 |
circulatory | 5, 6 |
clavicle | 10 |
close | 12 |
cochlea | 14 |
collar bone | 10 |
conception | 3 |
contraction | 16 |
cytosine | 4 |
D |
|
day(s) | 5, 6, 8, 10 |
development(al) | 3, 4, 6, 7, 9, 12, 13, 16 |
diaphragm | 9 |
digestive | 6, 13 |
distinguish(ed) | 12, 16 |
DNA | 4, 17, 18 |
E |
|
ear | 9, 14 |
early pregnancy factor (EPF) | 4 |
earth | 4, 17 |
ectoderm | 6 |
egg | 4 |
elbows | 10 |
electrocardiogram | 10 |
electrodes | 9 |
embryo | 3, 4, 5, 6, 7, 8, 9, 11, 13 |
embryology | 4 |
embryonic | 3, 4, 5, 7, 9, 11, 19, 20 |
embryonic period | 11, 20 |
encephalography | 9 |
endoderm | 6 |
energy | 15 |
enzymes | 13 |
epiblast | 6 |
epidermis | 11 |
estrogen | 16 |
extension | 11 |
eye(s) | 10, 11, 12, 15 |
eyelids | 10, 11, 12, 15 |
Page 29
F |
Page Links |
face | 11, 12, 13 |
Fallopian tubes | 4 |
fat | 13, 15 |
female | 10, 12, 13, 15 |
fertilization | 3, 4, 5, 6, 12, 14, 15, 16 |
fetal | 3, 5, 12, 13, 14, 15, 16 |
fetal period | 3, 12, 17 |
fetus | 3, 5, 6, 12, 13, 14, 15, 16 |
fingerprints | 12 |
fingers | 10 |
flattening | 9 |
fluid | 7, 11, 12, 14, 15 |
folding | 6 |
follicles | 14 |
forebrain | 6, 7 |
formation | 3, 8, 11, 12 |
function(s) | 3, 7, 21 |
fuse | 11 |
G |
|
genitalia | 12 |
germ cells | 8 |
germ layers | 6 |
gestational age | 3, 14 |
glands | 14 |
glucose | 12 |
grasp | 12, 16 |
grasping | 11 |
gravity | 11 |
grow(ing)(s) | 3, 5, 6, 9, 11, 14 |
growth | 6, 7, 10, 11, 12, 15 |
guanine | 4 |
H |
|
hair | 6, 11, 14 |
hand(s) | 8, 9, 10, 11, 12, 16 |
head | 5, 7, 9, 11, 12, 13 |
health | 15, 16 |
hearing | 7, 14, 15 |
hearing loss | 15 |
heart | 6, 7, 8, 10, 14, 15 |
heart rate | 14, 15, 20 |
heartbeat(s) | 20 |
helix | 4 |
hindbrain | 6, 7 |
hormone(s) | 5 |
hours | 4, 14 |
human | 3, 4, 5, 6, 11, 12, 16 |
human chorionic gonadotropin (hCG) | 5 |
hypoblast | 6 |
I |
|
implantation | 5 |
inner cell mass | 5, 6 |
intestine | 9, 12 |
J |
|
jaw | 10, 11, 12, 13 |
jaw movement | 11, 13 |
joints | 10, 11 |
Page 30
K |
Page Links |
kidneys | 6, 8, 11 |
knee | 10 |
L |
|
labor | 16 |
larynx | 12 |
learning | 7 |
left-handed | 11 |
leg | 15 |
licorice | 16 |
life cycle | 12 |
lifespan | 7 |
light | 12, 13, 15 |
limb(s) | 7, 11, 13 |
lips | 12 |
liver | 6, 8, 9 |
lungs | 8, 14, 16 |
lymphocytes | 9 |
M |
|
male | 11, 12, 13 |
man | 4 |
marrow | 13 |
maternal | 4, 5, 19 |
meconium | 13 |
medications | 5 |
memory | 7 |
menstrual cycle | 5 |
mesoderm | 6 |
metaphase | 4 |
meters | 17 |
midbrain | 6, 7 |
miles | 4, 17 |
million | 4, 7, 17 |
mitosis | 4 |
molecule(s) | 4, 17 |
morula | 5 |
mouth | 9, 11, 12, 13 |
move | 12 |
movement(s) | 7, 9, 10, 11, 13, 14, 16 |
mulberry | 5 |
muscle(s) | 6, 11 |
muscular | 11 |
N |
|
nails | 6 |
nerve(s) | 6, 11 |
neural | 11 |
neuromuscular | 9 |
newborn(s) | 11, 13, 14, 16 |
nipple(s) | 10, 13 |
noise | 15 |
noradrenaline | 14 |
norepinephrine | 14 |
nose | 12 |
O |
|
odors | 15 |
oocyte | 4 |
oogonia | 12 |
open(s) | 12, 13, 15 |
ossification | 10 |
ovaries | 4, 10 |
ovary | 4, 12 |
ovulation | 4 |
oxygen | 5 |
Page 31
P |
Page Links |
palms | 12 |
pancreas | 6 |
percent | 11, 12, 13, 15, 16 |
physiologic herniation | 9 |
placenta | 5, 19 |
postfertilization age | 9, 10, 13, 14, 15, 20 |
postmenstrual age | 3, 9, 13, 14 |
postnatal | 20 |
preference(s) | 11, 16 |
pregnancy | 3, 4, 5, 13, 15, 16 |
premature(ly) | 14, 15 |
prenatal | 21 |
problem-solving | 7 |
proportion | 13 |
protection | 7 |
pupils | 15 |
Q |
|
quickening | 13 |
R |
|
reflex | 13 |
reflexive(ly) | 9, 11 |
reopen | 15 |
reproductive | 4, 8, 12 |
respiratory | 6, 8, 14, 15 |
respond(s) | 13, 14, 15 |
response | 10, 12, 13, 14, 15 |
retina | 10, 15 |
right-hand | 11 |
rolling over | 11 |
roof | 13 |
rooting reflex | 13 |
rotation | 11 |
S |
|
sac | 6, 7 |
scalp | 14 |
sense(s) | 12, 13, 15 |
sex | 12 |
sigh | 12 |
skeletal | 11 |
skin | 6, 7, 11, 14, 15 |
skin layers | 14 |
sole(s) | 12 |
somersaults | 15 |
sounds | 14, 16 |
speech | 7 |
sperm | 4 |
spermatozoon | 4 |
spinal cord | 6 |
spontaneous | 9, 11 |
squinting | 11 |
startle | 10, 15 |
stem cells | 5, 13 |
stimulation | 12, 13 |
stress response | 14 |
stretch | 12 |
structure(s) | 3, 5, 6, 11, 14, 21 |
survival | 3, 14 |
swallow(ed)(ing) | 12, 15 |
system(s) | 3, 5, 6, 8, 9, 14, 16, 21 |
T |
|
taste | 13, 16 |
taste buds | 13 |
tears | 15 |
temperature | 5, 15, 19 |
testes | 11 |
testosterone | 11 |
thought | 7 |
thumb sucking | 12 |
thymine | 4 |
toes | 10, 12 |
tongue | 12, 13 |
tooth | 13 |
touch(ing) | 9, 11, 12, 13 |
trachea | 8 |
transparency | 7, 11 |
trillion | 3, 4, 17 |
trimester | 13, 15 |
trunk | 10 |
U |
|
umbilical cord | 5, 9, 12 |
umbilical vesicle | 6 |
urine | 11 |
uterine tube(s) | 4, 5 |
uterus | 4, 5, 11, 12, 16 |
V |
|
vascular | 11 |
vernix caseosa | 14 |
viability | 14 |
vocal cord development | 12 |
vocal ligaments | 12 |
W |
|
walking | 15 |
water | 12 |
weight | 11, 12, 13, 15 |
white blood cell | 9 |
windpipe | 8 |
woman | 4, 13 |
womb | 4, 14 |
wrinkled | 15 |
wrist | 8 |
Y |
|
yawns | 12 |
yolk sac | 6, 8 |
Z |
|
zygote | 3, 4 |