development and inheritance Flashcards
amphimixis
moment of conception
fertilization
fusion of two haploid (23 chromosomes) gametes, each containing chromosomes; produces zygote (46 chromosomes)
fertilization site
uterine tube within a day after ovulation
oocyte
contains everything needed to support development of embryo for nearly a week
ovum
oocyte completes meiosis II, becomes mature ovum
zygote
two fused haploid gametes, contains 46 chromosomes
morula
stage after 3 days of cleavage
gastrulation
forms third layer of cells in embryo (ectoderm, mesoderm, endoderm)
blastula
hollow sphere of cells, produced during the development of an embryo by repeated cleavage of a fertilized egg
four processes of first trimester
cleavage, implantation, placentation, embryogenesis
cleavage
first step after fertilization; zygote becomes pre-embryo; ends when blastocyst hits uterine wall
implantation
second step after cleavage; attachment of blastocyst to uterine wall
placentation
third step after implantation; blood vessels form around blastocyst; placenta develops to permit blood exchange between mother and embryo
embryogenesis
fourth step after placentation; formation of viable embryo; foundation for all major organ systems
braxton hicks contractions
false labor; occasional spasms in uterine musculature
stages of labor
dilation, expulsion, placental
dilation stage
begins with onset of true labor; cervix dilate; frequency of contactions increases; water breaks
expulsion stage
cervix dilated to 10 cm; contractions reach maximum intensity; ends when fetus leaves vagina
delivery stage
newborn infant enters outside world
APGAR newborn’s health assessment
assessment of newborn’s heart rate, breathing, skin color, muscle tone, and reflex response; 8-10 is healthy
extra-embryonic membranes
yolk sac, amnion, allantois, chorion
ectoderm
integumentary- epidermis, nails, hair follicles, hairs; glands communicating with skin
skeletal- pharyngeal cartilages (auditory ossicles)
nervous- all neural tissue
endocrine- pituitary gland and adrenal medullae
respiratory- mucous epithelium of nasal passageways
digestive- epithelium of mouth and anus; salivary glands
mesoderm
urinary- kidneys, nephrons
reproductive- gonads
connective tissues that support all organ systems
endoderm
endocrine- thymus, thyroid gland, pancreas
respiratory- respiratory epithelium
digestive- mucous epithelium, exocrine glands, liver, pancreas
urinary- bladder
reproductive- stem cells that produce gametes
genome
full set of genetic material (DNA) in our chromosomes
chromosomes
contain DNA and proteins
