Chapter 3- Embryogenesis and Development Flashcards
(28 cards)
earliest we can tell the sex of a baby
16 to 17 weeks
ampulla
widest part of fallopian tube where fertilization occurs
what happens after penetration of the sperm through the cell membrane of the egg
cortical reaction, a release of calcium ions (which depolarize cell preventing fertilization by multiple sperm and increases metabolic rate of newly formed diploid zygote)
where do fertilization and implantation occur?
fallopian tubes- fertilization
uterus- implantation
trophoblast cells
surround the blastocoel and give rise to chorion and later the placenta
placental development
trophoblastic cells –> chorion (extraembryonic membrane that develops into the placenta)
umbilical cord
2 arteries (carry deoxygenated blood and waste to placenta for exchange) and 1 vein (carries oxygenated blood with nutrients from placenta to embryo)
origin of the adrenal glands
adrenal cortex–> mesoderm
adrenal medulla–> ectoderm (b/c it contains some nervous tissue in it as well)
induction
ability of one group of cells to influence the fate of other nearby cells (process mediated by inducers)
Teratogens
substances that interfere with development, causing defects or even death of the developing embryo or fetus. (ex: alcohol, drugs, viruses, bacteria, and environmental chemicals)
what helps with neural tube closure
folic acid
stage of implantation during fetal development?
blastula stage (must be implanted for gastrulation)
what tissues do neural crest cells develop into?
PNS
Morphogens
Molecules that cause determination of cells, diffuse through the organism
apoptotic blebs
cell that can be digested by other cells (allows for recycling of materials)
necrosis
process of cell death in which a cell dies as a result of injury (can result in internal substances being leaked causing irritation of nearby cells or an immune response)
complete vs. incomplete regeneration
complete-replaced with identical tissue
incomplete-replaced with nonidentical in structure or function compared to lost tissue
senescence
biological aging. at the organismal level it represents changes in the bodys ability to respond to a changing environment.
placenta
where nutrients, gas, and waste exchange occurs through DIFFUSION without mixing mom and child blood types b/c they may be diff.
fetal vs. maternal hemoglobin
fetal hemoglobin has a higher O2 affinity
fetal vs. maternal organs
lungs (gas exchange at placenta) and liver (detoxification/metabolism in mothers liver) do not serve significant functions prior to birth
shunts to protect fetus organs from blood that aren’t in use
keep blood away from…
- lungs- foramen ovale (blocks R and L atrium connection) 2. ductus arteriosus (blocks leftover blood from pulmonary artery to aorta)
- liver- ductus venosus (blocks blood returning from placenta via umbilical vein directly to inferior vena cava
key events in 1st trimester
most organs have formed and bone is starts hardening, heart starts beating
key events in 2nd trimester
growth (9cm to 30/36cm), moves, face like human
