Test 1 Chapter 3

An expectant mother is at her first prenatal visit. She informs the nurse that she smokes cigarettes but has cut back to approximately 10 cigarettes per week and asks if she may continue to smoke this many per week. What would be the best response?

"Factors such as smoking and alcohol use may adversely affect your baby's development."

What is the most accurate response from a nurse when a pregnant woman having an ultrasound at 8 weeks of gestation asks if she may learn her expectant child's sex?

"The tenth week is when the external genitalia are visible on ultrasound."

* What takes place in the 8th week of development?

- Embryo has a human appearance - Purposeful movement occurs - Tail is gone - Sex organs form (ovaries and testes) - Beginnings of most external and internal structures form - Embryo enters fetal period. Becomes a fetus at 9 weeks.

* What takes place in the 29th week of development?

- Fetus assumes stable (cephalic) position - Central nervous system is funcitoning - skin is less wrinkled - spleen stops forming blood cells and bone marrow starts forming blood cells - increased surfactant is present in lungs

* How long does the sperm stay viable for?

5 days

* What is the normal length of the umbilical cord?

55 cm (22inches)

What functions does the amniotic fluid have?

Allows buoyancy and fetal movement Maintains an even temperature Allows for symmetrical growth

* What takes place in 3rd week of development? Missed period is noticed

Cardiovascular - Single tubular heart is formed and begins pumping Nervous - Neural tube forms - Spinal cord and brain appear

What is hPl? AKA hCs

Causes decreased insulin sensitivity and utilization of glucose by the mother, making more glucose available to fetus to meet growth needs.

* Membranes in the uterus are:

Chorion Amnion Yolk Sac Germ Layers

* What are the 46 chromosomes in the body called

Diploid number of chromosomes

* Biological developement is influenced by what external factors?

Drug use (prescribed)

The fetal nervous system is formed by the germ layer known as the

Ectoderm

* What are the 3 Germ Layers?

Ectoderm Mesoderm Endoderm

What do the Germ layers consist of?

Ectoderm = outer layer of skin, oil glands and hair follicles skin, nails and hair, external sense organs, and mucous membrane of the mouth and anus. Mesoderm = True skin, skeleton, bone and cartilage, connective tissue, muscles, blood and blood vessels, kidneys and gonads. Endoderm = Linings of trachea, pharynx, bronchi, digestive tract, bladder and urethra.

* What is the 2nd to 8th week of development called?

Embryonic stage

Which hormone is produced by the placenta?

Estrogen

* When does the forman ovale close?

Temporarily 2 hours after birth Permanently by 3 months

*When does the ductus venosus close?

Temporarily when the cord is cut Permanently in 1 week

*When does the ductus arteriosus close?

Temporarily within 15 hours Permanently in 3 weeks

* Where does fertilization occur?

The outer third of the fallopian tube, near the ovary.

A woman who wants to become pregnant should avoid all medications unless they are prescribed by a physician who knows she is pregnant, because:

The placenta allows most medications to cross into the fetus.

* What covers and cushions the cords vessels and keeps the 3 vessels seperated?

Whartons Jelly

* The process of mitosis in the ovum is called

oogenesis

The purpose of the foramen ovale is to:

reduce blood flow to the lungs

The childs sex is determined by the :

sperm, which contains either an x or Y chromosome

* During meiosis the # of chromosomes is reduced by half making it 23. This is called :

the haploid number of chromosomes

When a couple has unprotected sexual intercourse 4 days before the woman ovulates, the risk of the woman becoming pregnant is:

very low, because that is not the woman's fertile period

* The ovum contributes what chromosome?

x (gamete)

* What chromosomes make a female child?

x and x

* What chromosomes make a male child?

x and y

* The sperm contributes what chromosome?

x or y (gamete)

* What takes place in the 17th week of development?

- Genitalia and leg movements are visable on ultra sound and can be felt by mom - Bones are ossified - Eye movements occur - Fetus sucks and swallows amniotic fluid - Ovaries contain ova - No sub q fat is present - Thin skin allows blood vessels of scalp to be visible

* What takes place in the 36th week of development?

- Sub q fat is present - Skin is pink and smooth - Grasp reflex is present - circumferences of head and abdomen are equal - Surge in lung surfactant production occur

* What takes place in the 25th week of development?

- Wrinkled skin, lean body - eyes are open - fetus is now VIABLE at 20 weeks - Mother feels stronger movement (quickening) - Fetus has schedule of sleeping and moving - Vernix is present on skin - Lanugo covers body - Brown fat is formed - LUNGS begin to secrete SURFACTANT - Fingernails are present - Respiratory movements begin

* How does the circulation before birth go?

- blood enters from cord, half goes to liver and the other goes to inferior vena cava through ductus venosus. - It then goes to the right atrium and most then goes to left atrium through the foreman ovale - A small amount goes into the lungs by the right ventricle. The rest from the right joins with the left ventricle through the ductus arteriosus. - It circulated the fetus and is then returned to the placenta thought he umbilical artery.

Which statements are true about the placenta?

-It produces estrogen which stimulates the development of breasts for lactation. -It serves as an organ for fetal respiration, nutrition, and excretion. -It functions as an endocrine gland during the pregnancy.

* What are the 3 fetal circulatory shunts?

1. Ductus venosus 2. Foramen ovale 3. Ductus arteriosus

* The 3 effects of estrogen not related to pregnancy are:

1. Increased skin pigmentation (mask of pregnancy) 2. Vascular changes in the skin and the mucous membrane of the nose and mouth. 3. Increased salivation

* What are the 5 functions of the amniotic sac?

1. Maintains an even temp 2. Prevents the amniotic sac from adhering to the fetal skin 3. allows symmetrical growth 4. allows buoyancy and fetal movement 5. Acts as a cushion to protect the fetus and the umbilical cord from injury.

* Progesterone is produced by the corpus luteum first and the placenta later. It has what 4 functions?

1. Maintains the lining of uterus for implantation of the zygote 2. Reduces contractions to prevent abortion. 3. Prepares the glands of the breast for lactation. 4. Stimulates the testes to produce testosterone, which aids the male fetus in developing the reproductive tract.

* What 4 hormones are produced by the placenta?

1. Progesterone 2. estrogen 3. Human chorionic gonadotropin (hcG) 4. Human placental lactogen (hPL)

* Estrogen has what 3 main functions?

1. Stimulate uterine growth 2. Increase the blood flow to uterine vessels 3. Stimulates the development of breast ducts to prepare for lactions

* When is external genitalia visible by ultrasound?

10th week

* Fertilization includes what chromosomes?

23 chromosomes from sperm and 23 from the ovum. Therefore it returns to the diploid number of chromosomes.

* When is the fetus considered full term?

38-40 weeks

* Each body cell contains how many chromosomes?

46

* Yolk sac

Forms on the 9th day - functions only during embryonic stage to produce RBC - 6 weeks till liver takes over

* What are Dizygotic (DZ) twins?

Fraternal have 2 placentas and are not the same.

* What takes place in the 4th week of development?

GI - Esophagus and trachea seperate - stomach forms Nervous - Neural tube closes - Forebrain forms Muskuloskeletal - upper and lower limb buds appear Senses - ears and eyes begin to form

*What are Monozygotic (MZ) twins?

Identical twins (share one placenta)

* What does folic acid prevent?

Neural tube defects

The maternal hormone _________________ reduces uterine contractions to prevent spontaneous abortions.

Progesterone

* How many arteries and veins are in umbilical cord?

Remember AVA 2 arteries and 1 vein

* What takes place in the 6th week of development?

Senses - Auditory canal forms - eyes are obvious Cardiovascular - Heart has all 4 chambers GI - Nasal cavity and upper lip form

* How does the circulation after birth go?

Shunts are not needed after birth when the infant breaths. - the forman ovale will close because pressure in the right side of heart falls as lungs become fully inflated. - Blood oxygen level rises which causes the ductus arteriosus to constrict - Ductus venosus closes when the flow from the cord stops

* The process of mitosis in the sperm is called:

Spermatogenesis

* Amnion

The second membrane that is thin and envelopes & protects the embryo. - along with chorion it forms the amniotic sac

* What is HcG?

The signal sent to corpus luteum that conception has occured. It produces estrogen and progesterone to sustain pregnancy.

Why are twins often born early?

The uterus becomes overdistended

T or F The placenta is much larger than the developing infant during early pregnancy, but the fetus grows faster and the placenta ends up being smaller.

True

What is the usual site of implantation for the female reproductive system?

Upper section of the posterior uterine wall ~The zygote usually implants in the upper section of the posterior uterine wall.

* Chorion

developes from the trophoblast (outer layer of embryonic cells) and envelopes the amnion, embryo, and yolk sac. - Contains the villi

* What does the Ductus venosus do?

diverts blood away from the liver as it returns to placenta

* What does the Ductus arteriosus do?

diverts blood from pulmonary artery into the aorta.

* What does the Foramen ovale do?

diverts blood from the right atrium directly to the left atrium, rather than circulating it to the lungs