Unit 2 Flashcards
(121 cards)
Heredity
Process of transmitting biological traits from parents to offspring through genes
Genetics
The study of heredity and how genes work
Chromosomes
- 23 pairs
- 22 are the same (autosomes)
- 1 pair are sex chromosomes (Females=XX Males=XY)
Amniocentesis
- done between 12-16 weeks
- sample of amniotic fluid taken by syringe
- tests for chromosomal or metabolic disorders
Ultrasound Sonography
- high frequency sound waves direction into abdomen
- echo is transformed into visual image of fetus’s inner structures
- 3D and 4D imagery
Chorionic villus test
- small sample of placenta is removed
- 8-11 weeks
Maternal blood test
- diagnostic test to assess neural tube defects
- administered at 14-20 weeks only if at risk for defects in the formation of brain/spinal cord
Why would someone go for genetic testing?
- possibility of hereditary disorder is high in family history
- you or your partner are over 37 years old (quality of eggs deteriorates)
- prenatal ultrasound indicates a risk of a birth defect
Gamete
- sex cell
- male = sperm
- female = egg
- one set of chromosomes
Zygote
- fertilized egg cell
- 2 sets of chromosomes
- divides up to holding 150 cells inside
- lasts for 14 days (2 weeks)
- after 2 weeks, it implants into the uterus wall (confirmed pregnancy)
Blastocyst
- stage after zygote
- inner mass of cells
- fertilized egg cell
- cell division where the cells become types
- becomes yolk sac, fetus, and amniotic sac
Trophoblast
- external part of egg (outer layer)
- grows into uterus lining
In Vitro Fertilization
- ova are surgically removed from the ovaries and fertilized by sperm in the lab
- divide until the 16 or 32 cell stage
- cells inserted into uterus
- implants to uterine wall
- 1 in 7 are successfully implanted to become healthy baby/just under 20% success rate
Gamete Intrafallopian Transfer (GIFT)
- gamete is a haploid reproductive cell, either egg or sperm
- doctor inserts unfertilized eggs and sperm directly into woman’s fallopian tube
- success rate is almost 30%
Intrauterine (artificial) Insemination (I.U.I.)
- frozen sperm placed directly into uterus (passes cervix and upper vagina)
- naturally seeks egg
- success rate is 10%
Zygote Intrafallopian Transfer (ZIFT)
- egg fertilized in lab
- zygote then transferred to Fallopian tube
- success rate is 25%
Intracytoplasmic Sperm Injection (ICSI)
- doctor uses microscopic instrument to inject a single sperm into the egg in a lab (selection based on high mobility, health, form)
- zygote returned to woman’s body
- success rate is 25%
Ovum Donation (2)
- woman volunteers to be a surrogate mother, artificially inseminated with sperm from an infertile woman’s husband and carries baby to term
- woman volunteers her eggs to be removed, artificially inseminated, and inserted into another woman’s uterus
Key features doctors look for at 8 weeks?
- heartbeat
- size
- movement
What is sperm washing?
Separates healthy sperm (heavier/denser) from white blood cells, mucous, seminal fluid, dead sperm, and slow moving sperm
Difficulties sperm must overcome to fertilize an egg?
- acidic atmosphere of the vagina
- narrowness of uterotubal junction (entrance to cervix)
- white blood cells see sperm as pathogenic “foreign invaders”
Uterus
Fluid filled sac where fetus develops
Amniotic sac
Soft lining of uterus; amniotic fluid is fluid the fetus grows in inside the womb
Cervix
Neck of uterus, joins with vagina; strong muscles; dilates to allow baby to pass during birth