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Maternal Child Nrsng
Question | Answer |
---|---|
The development of ova in the woman and sperm in the man. | gametogenesis |
formation of female gamete | Oogenesis |
formation of male gamete | spermatogenesis |
the process in which cells divide to form gametes | meiosis |
When does ovulation occur? | 14 days before a womans next menstrual cycle would begin |
where is the mature ovum released? | on the surface of the ovary where it is picked up by the fallopian tube and transported through the tube and awaits fertilization |
when does the ovum enter the uterus | 3 days after its release from the ovary |
How long does sperm last after ejaculation? | most survive no longer than 24 hours, but few may remain fertile for up to 5 days |
Are sperm immidiatly ready to fertalize the ovum? | No. During the trip to the ovum, they undergo changes that enable one of the to penetrate the protective layers surrounding the ovum, a process called capacitation. |
When does fertilization occur? | when one spermatozoon enters the ovum and the 2 nuclei containing the parents chromosomes merge. |
When sperm enters the ovum, where is the ovum fertilized? | the distal third of the fallopian tube near the ovary |
Describe the process of fusion between the sperm and ovum | The 23 chromosomes from the sperm unite with the 23 chromosomes from the ovum restoring the total number to 46 |
When is fertilization complete and cell division can begin? | when the nuclei of the sperm and ovum unite |
The pre-embryonic period | First 2 weeks after conception |
What happens around the 4th day after conception? | The fertilized ovum, now called a zygote, enter the uterus |
When a zygote divides until it reaches 16 cells , it is called a... | morula |
Describe the entry of the zygote into the uterus | 1) When the blastocyte contains approx. 100 cells, it enters the uterus. 2) it lingers in the uterus another 2-4 days before beginning implantations. Cont next slide... |
Cont from previous slide... | 3) The endometrium, now called the decidua, secretes rich fluids to nourish the zygote before placental circulation is established. |
What is critical for the implantation in the decidua fro continued development? | Proper time and place in the uterus |
When does the implantation in the decidua happen? | between the 6th and 10th day after conception. |
Why does the zygote secret HCG? | To signal that the woman requires a continuing supply of estrogen and progesterone to tell the body that a pregnancy has begun |
Why is the site of implantation important? | Because that is where the placenta develops |
Where does normal implantation develop? | In the upper uterus, slightly more often on the posterior wall than the anterior wall. |
What will form to nourish the zygote by diffusion because the circulatory system is not yet developed? | Primary chorionic villi. The villi will eventually form from the fetal side of the placenta |
When is the zygote embedded with the uterus? | 10 days |
The beginning of the 3rd week through the 8th week is considered to be the... | Embryonic period |
What are teratogens? | drugs, viruses, radiation and infectious agents |
Zygote | cell formed by union of sperm and ovum |
embryo | 3rd-8th week of development |
fetus | 9th week until birth |
What are the 3 primary cell layers that differentiate during the embryonic stage | ectoderm, mesoderm, endoderm...GROWTH IS RAPID |
What body segments appear in the 3rd week of prenatal development? | neural tube forms, primitive brain, primitive spinal cord and a primitive or tubular heart begins beating at 22 to 23 days. |
Embryo charecteristics in prenatal development week 4 | C shaped with tail and head, neural tubes closed, ears and eyes are apparent, upper extrmities appear as buds, partitioning of the heart into 4 chambers begins, esophagus and trachea seperate |
Embryo charecteristics in prenatal development week 5 | Heart is beating and continuing to develop into 4 chambers, limbs continue to form |
Embryo charecteristics in prenatal development week 6 | Heart has 4 chambers, facial development begins with eyes, ears, and nasal pits |
Embryo charecteristics in prenatal development week 7 | Face is more human looking, eyelids begin to form, fast intestinal growth |