2. In this chapter, an attempt will be madeto explain the major happenings during thenine months before birth, to emphasize thesignificance of the moment ofconception, and to show what environmentaland psychological factors affect the course ofdevelopment.
3. How Life Begins vagina, uterus, fallopian tube and ovaries testes, epididymis and vas deferens Union of sperm and egg
4. 1. Many sperm try to penetrate the egg.2. The first sperm through succeeds.3. The outside of the egg swells, casting away the othe sperm. The spermsnucleus seeks the eggs nucleus.4. The 2 nuclei merge and chromosomes pair up.5. The fertilized egg divides.The fertilization process
5. Gestation Period 260 days- Trimester:1. Germinal2. Embryonic3. Fetal
6. Germinal Stage (Fertilization-2 weeks)
7. Timetable of Prenatal DevelopmentPeriod of the Zygote (fertilization toend of second week) The size of the zygote- that of apinhead- remains unchangedbecause it has no outside source ofnourishment. As it passes down the fallopian tubeto the uterus, it divides many timesand separates into an outer andinner layer. An outer layer later develops into theplacenta, the umbilical cord, and theamniotic sac, and the inner layerdevelops into a new human being. About 10 days after fertilization, thezygote becomes implanted in theuterine wall.
8. Embryonic stage- age 2 weeks-2 months Develops into a miniature humanbeing. Major development occurs, in thehead region first and the extremitieslast. All the essential features of the bodyare established. The embryo begins to turn in theuterus, and there is spontaneousmovement of the limbs. The placenta, the umbilicalchord, and the amniotic sac develop. At the end of the 2nd prenatalmonth, the embryo weighs, on theaverage, 1 ounces and measuresin length 1 inches.
9. Fetal Stage- age 8 weeks-birth Changes occur in the actual size of the partsalready formed and in their functioning. No newfeatures appear in this time. Some internal organs are well enoughdeveloped to begin to function. Heartbeat can bedetected by about the 15th week The different internal organs have assumedpositions. Nerve cells increase rapidly in number. Fetal movements appear- rolling and kicking andshort or quick. By the end of 7th lunar month, fetus is wellenough developed to survive. By the end of the 8th lunar month the fetal bodyis completely formed.
10. Fetal Development (adapted from Jane Beltran) First Lunar Month- Foundations formed for nervous system, genito-urinary system, skin, bones andlungs.- Buds of arms and legs begin to form.- Rudiments of eyes, ears, and nose appear.
11. Second Lunar Month- Fetus markedly bent- Head disproportionately large, owing to brain development- Sex differentiation begins- Centers of bone begin to ossify
12. Third Lunar Month- Fingers and toes are distinct- Placenta is complete- Fetal circulation is complete
13. Fourth Lunar Month- Sex is differentiated- Rudimentary kidneys secrete urine- Heart beat is present
14. Fifth Lunar Month- Lanugo (fine downy hair covering a human fetus) covers entire body- Fetal movements are felt by mother- Heart sound are perceptible with fetoscope
16. Seventh Lunar Month- Skin is red- Papillary membrane disappears- If born, infant cries, breathes, but usually expires
17. Eight Lunar Month- Fetus is viable- Eyelids open- Fingerprints are set- Vigorous fetal movement occur
18. Ninth Lunar Month- Face and body have loose wrinkled appearance due to subcutaneous fatdeposit- Lanugo disappears- Amniotic fluid decreases somewhat
19. Kinds of BirthNatural, or Spontaneous birth- headfirst positionBreech birth- buttocks appear first, followed by the legs, and finally, theheadTransverse birth- the fetus is positioned crosswise in the mothersuterus. Instruments must be used for delivery unless the position can bechanged before the birth process beginsInstrument birth- when the fetus is too large to emerge spontaneously orwhen its position makes it normal birth impossible, instruments must beused to aid in delivery.Caesarean section- if x-rays taken during the part of pregnancy indicatethat complications may result if the infant emerges through the birthcanal, the baby is brought into the world through a slit made surgically inthe mothers abdominal wall.
20. Natural or Spontaneous Breech birth
21. Transverse birth Instrument birth
22. Caesarean Section
23. Your Logo
24. Infancy is the beginning or early period of existence as anindividual rather than a parasite in the mothers body.
25. Adjustments of InfancyTemperature Changes- there is a constant temperature of 100F in theuterine sac, while temperatures in the hospital or way home may varyfrom 60-70FBreathing- when the umbilical cord is cut, infants must begin to breatheon their own.Sucking and swallowing- the infant must now get nourishment bysucking and swallowing, instead of receiving it through the umbilicalchord. These reflexes are imperfectly developed at birth, and the infantoften gets less nourishment than is needed and thus loses weight.Elimination- the infants organs of elimination begin to work soon afterbirth; formerly, waste products were eliminated through the umbilicalchord
26. Indications of the difficulty of adjustment to postnatal lifeLoss of weight- because of difficulties in adjusting to sucking andswallowingDisorganized behavior- such as irregularities in breathing rate, frequenturinations and defecations.Infant mortality- the rate of infant mortality during the first 2 days ofpostnatal life is high.
27. Physical developmentThe head grows the fastest and matures the earliest, followed bythe rest of the body downward. In addition, those parts that are closest tothe center of the infants body (e.g., the trunk) grow faster and matureearlier than do parts that are farther from the center (e.g., the hands). Thephysical structure of the brain develops rapidly as well.