click below
click below
Normal Size Small Size show me how
physio prego
prep for conceptio in fe,
Question | Answer |
---|---|
gametogenesis | devo of ova in woman & sperm in man |
ovulation and ejaculation relate to human conception by what? | human fertilization occurs when the sperm penetrates an ovum and unites it, |
implantation of the embryo is done how? | mature ovum is released on the surface of ovary, picked up by the fallopian tube, carried to uterus where it may become fertilized, 3 days after release from ovary |
how is it nourished? | primary chorionic villi form that nourixh zygote by diffusion b/c the circ system is not yet established, villi will form fetal side of placenta, |
what is normal prenatal development from conception to birth | zygotic stage,zygote is fully embedded with in uterus by 10 days, mbrionic period 3rd week through 8th week after concepton, then differentiation of cells, fetus 9th week til birth |
what is formation of female gamete? | Oogenesis, spermatogenesis for men, Meiosis is the process in which cells divide to form gametes, Ovulaton at 14 days before menses, survives 24 hrs after ovulation |
Embrionic stage 3 primary cell layers differentiate? | Ectoderm, Mesoderm, Endoderm; growth is rapid, develops human appearance, susceptivle to teratogenic agents |
prenatal development week 3 first body segments are? | neural tube, primitive brain, primitive spinal cord, primitive/tubular heart begins beating 22-23 days |
prenatal development week 4, how long is embryo, what is ratio of head to body, and how are segments affected? | 1/5 in long, head is third of total length, ebryo shape resembles C with tail/head, neural tube close, face/URT begin, Ears/eyes, UE appear as buds, Partitioning of the heart into 4 chambers begins, Esophagus and trachea separate |
Prenatal development Week 5 what happens to heart, head, and limbs? | heart is beating/continuing to develop 4 chambers, limbs continue to form, head is large due to rapid brain growth |
prenatal development week 6 results in what features/? | heart has 4 chambers and facial development of eyes, ears, and nasal pits begins |
prenatal development week 7 results in what changes? | rapid development makes face look more human, eylids form, fast intestinal growth occurs. |
prenatal development week 8 results in | little more than one inchlong embrio, fingers/toes formed, purposeful movement unfelt by Mom, heart beats at 40-80/per min |
Fetal period at 9 weeks is what kind of period related to embrionic and zygotic? | longest part of prenatal development, begins 9 weeks after conception and ends with birth, teratogens may damage already formed structures but are less likely to cause major structural |
weeks 9-12 commonly result in what development of the fetus? | head is half the total length of the fetus at the start of this period, first fetal movements begin (too slight for Mom to know), eyes close at 9 weeks/reopen at 26 weeks, Urine production begins, end of 12th: gender |
week 13-16 incurs what two metabolic factors? | Grows rapidly i length, quickening (fetal movement occurs) |
Weeks 17-20 what happens? | vernix covers skin, lanugo is present, eyebrows and head hair appear, Brown fat(special heat producing fat that helps newborn maintain temp stability after birth) is deposited |
Prenatal Development Weeks 21-24 | Fetus appears thin due to minimal fat, skin is translucent and red, Lungs begin to produce surfactant although alveoli immature, most systems still extrmely immature and fetal survival not likely |
what are the three vessel shunts of the prenatal circulatory system? |