Conception E1 Flashcards
Define Gamete
Sperm or Ova
Fertilization
The process where the two gametes (sperm and ova) form a single new cell called a zygote
Meiosis vs Mitosis
Meiosis: Gamete formation
Mitosis: Every other cell replication
How many ova/sperm does someone have
400,000 ova at birth
Several 100 million sperm produced per day in men
Germinal stage
Conception-Week 2
Embryonic Stage
3-8 weeks
Fetal Stage
9-42 weeks
Threats to prenatal development
Mom/Dad behaviors; TORCHES panel, mom diet + mom age
Age > 30 or Adolescents at risk for LBW, down syndrome, higher infant mortality rates
Rubella, Chicken Pox/Mumps, Syphilis/Gonorrhea threats to prenatal development
Rubella: prior to 11th week can cause blindness, deafness, heart defects or brain damage
Chicken pox/mumps: birth defects + miscarriage
Syphilis/Gonorrhea: Transmission to child
Germ Layers
Ectoderm, Mesoderm, Endoderm
Ectoderm Contents
Epidermis, glands, nails, hair, CNS, PNS, tooth enamel, floor of amniotic cavity
Mesoderm
Bone + teeth, muscles, dermis, connective tissue, cardiovascular, spleen, urogenital system
Endoderm
Epithelium for respiratory and digestive tracts, glandular cells, roof of yolk sak
Cell membranes
Amnion: Inner cell membrane develops from cells of blastocyst (cluster of dividing cells)
Chorion: Outer cell membrane, contains villi on surface, covers fetal side of placenta
Amniotic Fluid
Comes from maternal blood via diffusion
800-1200mL at term
Fetus will swallow, in/out of lungs and urinate, should be clear
Oligohydramnios
<300 mL r/t renal abnormalities
Polyhydraminos/hydramnios
> 2L r/t GI and other malformations
Yolk sac
Aids in transferring maternal nurtients/oxygen (diffused through chorion that becomes part of the placenta) Blood/plasma cells made keeps the pregnancy viable until placenta takes over
Umbilical Cord
AVA - Two arteries one vein
At term: 2 cm diameter, 30-90 cm long
Whartons Jelly: surrounds
True knot: looks like a knot
False knot: curved/bent in a way to create a cut in circulation
Nuchal Cord: wrapped around neck of fetus
Purpose of placenta
Metabolic exchange: Respiration, nutrition, excretion/storage
Hormones: HcG, human placental lactogen, progesterone
Pulmonary surfactants (active phospholipids)
Maintains proper function of lungs + gas exchange
Lecithin: Critical alveolar surfactant
Sphingomyelin
2:1 (L:S) indicates lung maturity
Sensory awareness
Sound, Light: 24 wks
Taste: 16 wks
Rate of Multiples
<3% of all
Rate of muliples in fertility drugs
1 in 10, more likely in older mom
Monozygotic Vs Dizygotic
Mono: Identical ovum splits during first two weeks of gestation
Dizygotic: 2 separate ova are fertilized by separate sperm
