Maternity Nursing Chap 5 Flashcards
At ovulation, the ______ is released from the ruptured ovarian follicle. The cilia of the uterine tube capture(s) the ovum and propel(s) it through the uterine tube toward the uterus. Ova are fertile for about 24 hours after ovulation.
ovum
Following ejaculation, _______ reach the site of fertilization in an average of 4 to 6 hours and remain viable in a woman’s reproductive system for 2 to 3 days. With the process of capacitation, the protective coating from the sperm heads is removed, allowing enzymes to escape. Fertilization occurs in the ampulla of the uterine tube. Once penetrated by a sperm, the membrane surrounding the ovum becomes impenetrable through a process termed the zona reaction.
sperm
With the fusion of the male and female _______, the diploid number of chromosomes is restored. The new cell is called a zygote. Within 3 days a 16 cell ball called the morula is formed. A cavity develops within this ball of cells, creating the blastocyst, which is implanted into the endometrium 6-10 days after conception. The endometrium is now called the decidua. Fingerlike projections called chorionic villi develop from the trophoblast. These projections tap into the maternal blood vessels in teh decidua basalis.
nuclei
List the function of the yolk sac:
aids in transferring maternal nutrients and oxygen, which have diffused through the chorion, to the embryo
List the function of the amniotic membranes and fluid:
- helps maintain a constant body temperature
- serves as a source of oral fluid and as a repository for waste
- cushions the fetus from trauma by blunting and dispersing outside forces
- allows freedom of movement for musculoskeletal development
- fluid keeps the embryo from tangling with the membranes, facilitating symmetric growth of the fetus
List the function of the umbilical cord:
2 arteries carry blood from the embryo to the chorionic villi, and one vein returns blood to the embryo
List the function of the placenta:
as a means of metabolic exchange
True or False: All normal human somatic cells contain 46 chromosomes.
True
True or False: Hemophilia and color blindness are examples of sex chromosome abnormalities caused by nondisjunction during gametogenesis.
False
True or False: Neural tube defects and cleft lip and palate result from a combination of genetic and environmental factors.
True
True or False: For a recessive trait to be expressed in their offspring, both parents must contribute the abnormal gene.
True
True or False: In autosomal dominant inheritance, if one parent is affected by the disorder, there is a 100% chance of passing the abnormal gene to an offspring during each pregnancy.
False
True or False: Cystic fibrosis and phenylketonuria, both inborn errors of metabolism, follow the autosomal dominant inheritance pattern.
False
-autosomal recessive inheritance (PKU, galactosemia, maple syrup urine disease, Tay-Sachs disease, sickle cell anemia)
True or False: The stage of the fetus lasts from 9 weeks of gestation until the end of pregnancy.
True
True or False: The umbilical cord is composed of two veins, one artery, and Wharton’s jelly.
False
True or False: Human chorionic gonadotropin, which is produced by the placenta, reaches its peak serum level at 24 weeks gestation.
False
-7 to 10 days after conception, shortly after implantation.
True or False: The corpus luteum produces estrogen and progesterone to maintain the pregnancy until the placenta is mature enough to take over as an endocrine gland.
True
True or False: The placenta functions as an effective barrier to substances such as viruses and drugs, thereby protecting the fetus from their potentially harmful effects.
False
True or False: Oligohydramnios is associated with fetal renal abnormalities.
True
True or False: Meconium, fetal waste products in the intestine, can be passed into the amniotic fluid if fetal hypoxia occurs.
True
True or False: If a couple gives birth to a child with an autosomal dominant disorder, there is a 50% reduction in risk that the next pregnancy will result in an affected child.
False
True or False: Fetal viability is first reached at 30 weeks of gestation.
False
-20 weeks after conception
True or False: The limitations on survival outside the uterus are based on central nervous system function and oxygenation capability of the lungs.
True
True or False: The occurrence of multifetal pregnancies with three or more fetuses has steadily decreased as are a result of increased exposure to teratogens.
False
Describe the location and the purpose for the fetal circulatory structures: ductus venous, ductus arteriosus, and foramen ovale:
- ductus venous: liver bypass
- ductus arteriosus: lung bypass
- foramen ovale: shunt between the artia; lung bypass
What is unifactorial inheritance:
-inheritable characteristic is controlled by a single gene, recessive or dominant
Examples of common autosomal dominant disorders:
- Marfan syndrome
- neurofibromatosis
- myotonic dystrophy
- Stickler syndrome
- Treacher Collins syndrome
- achondroplasia (dwarfism)
Examples of common autosomal recessive disorders:
- PKU
- galactosemia
- maple syrup urine disease
- Tay Sachs disease
- sickle cell anemia
- CF
X-linked inheritance:
- transmission of abnormal genes on the X chromosome
- both males and females can be affected
- abnormality tends to be less severe in females because they also have a normal gene on their second X chromosome
Multifactorial inheritance:
-congenital disorder results from a combination of genetic and environmental factors
