chapter 2.2 Flashcards
fertilization
the process by which a sperm and an ovum - the male and female gametes, respectively - join to form a single new cell
conception
the joining of sperm and ovum to create the single celled zygote from which all of us began our lives
prenatal period
the germinal, embryonic and fetal stages
germinal stage
the first and shortest stage of the prenatal period, which takes place during the first two weeks following conception
-zygote divides and grows and implants on uterus wall.
0methodical cell division: three days after fertilization the organism consists of 32 cells and doubles the next day
placenta
a conduit b/w the mother and fetus, providing nourishment and oxygen by the umbilical cord
embryonic stage
the period from 2-8 weeks following fertilization during which significant growth occurs in the major organs and body systems
- child is an embryo
- ectoderm, endoderm and mesoderm present
ectoderm
skin hair teeth sense organs and brain and spinal cord
endoderm
inner layer, produces the digestive system, liver, pancreas and respiratory system
mesoderm
the muscles, bones, blood and circulatory system are forged
fetal stage
the stage that begins at about eight weeks after conception and continues until birth
- major organs differentiated
- now called a fetus
fetus
a developing child, from eight weeks after conception until birth
REM sleep is important for
brain development
fetal origins theory
framework for understanding adult outcomes in health, the basic idea of which is that the uterine environment programs the genes to prepare for a certain type of environment
infertility
the inability to conceive after 12-18 months of trying to become pregnant
-correlated with age
artificial insemination
a process of fertilization in which a man’s sperm is placed directly into a woman’s reproductive tract by a physician
In vitro fertilization (IVF)
a procedure in which a woman’s ova are removed from her ovaries and fertilized with a man’s sperm in a laboratory
miscarriage
spontaneous abortion - occurs when the embryo detaches from the wall of the uterus and is expelled before the child can survive outside the womb
abortion
mother chooses to terminate the pregnancy
teratogen
a factor that produces a birth defect
-the brain is most susceptible to structural damage 15-25 days after conception, the heart is most vulnerable 20-40 days after conception
Mothers diet
high nutrient diets- fewer complications, easier labour, generally healthier baby
supplementation of folic acid and iodine
- beneficial effects on fetal brain development
- excessively high can lead to anxiety and hyperactivity in children
mothers age
- women over 35 are at greater risk for a variety of complications (premature, low birth weight bc of the decline of the condition of their eggs)
- by 42, 90% of eggs not normal (1 in 100 with down syndrome)
- 50 (1 in 4 with DS)
rubella and pregnancy
before 11th week of pregnancy can cause blindness, deafness, heart defects, or brain damage in the baby,
chicken poz
create birth defects