Term
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Definition
-trophoblast implantation
-inner layer of cells
-remains around blastocyst |
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Term
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Definition
-trophoblast implantation
-outer layer of cells
-cells lose pl. mem. and contents invade and digest endometrium
-blastocyst burrows into endometrial lining
-makes room for blastocyst |
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Term
| human chorionic gonadotropin (hCG) |
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Definition
-secreted by trophblast cells, later the chorion
-promts corpus luteum to continue secretion of progest. and estrogen
-hCG levels rise until end of 2nd month, then decline as placenta secretes proges. and estr. |
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Term
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Definition
-cells develop from the ICM and line the trophoblast
-these form the chorion and chroionic villi |
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Term
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Definition
-grow into blood-filled lacunae
-vascularized by umbilical arteries/veins
-lie immersed in maternal blood |
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Term
| decidua basalis (maternal tissue) |
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Definition
| part of the endometrium outside of chorionic villi |
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Term
| decidua capsularis (maternal tissue) |
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Definition
-part of the endometrium at the uterine cavity face of the implanted embryo
-lumen of uterus |
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Term
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Definition
-combo of chorionic villi and decidua basalis
-fully formed and func. by end of 3rd mt
-hormone production
-oxy, nutrient, waste exchange |
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Term
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Definition
-epiblast cells from a transparent sac filled with amniotic fluid
-protects embryo
-maintains temp
-freedom of movement and prevents parts from fusing together
-am. fluid comes from maternal blood, and later from fetal urine |
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Term
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Definition
-hangs from ventral surface of embryo
-from hypoblast
-later forms part of digestive tract
-source of earliest blood cells and veseels |
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Term
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Definition
-small outpocketing at caudal end of yolk sac
-structural base for umbilical cord (connective tissue)
-becomes part of urinary bladder |
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Term
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Definition
-helps form placenta
-encloses the embryonic body and all other membranes |
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Term
| the 4 extraembryonic membranes are... |
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Definition
| amnion, yolk sac, allantois, and chorion |
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Term
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Definition
| week 3. embryonic disc becomes a 3 layered embryo with mesoderm, ectoderm, and endoderm |
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Term
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Definition
-rod of mesodermal cells that serves as axial support.
-directly beneath primitive streak |
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Term
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Definition
| nervous system and skin epidermis |
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Term
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Definition
| epithelial linings of digestive, respiratory, and urogenital systems |
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Term
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Definition
-after gastrulation
-formation of body organs and systems
-day 16
-8th wk all organ systems are recognizable and end of embryonic period |
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Term
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Definition
-occurs in ectoderm
-1st event of organogenesis
-gives rise to brain and spinal chord
-happens right over notochord |
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Term
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Definition
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Term
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Definition
| incomplete closure of neural tube |
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Term
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Definition
-somites, intermediate mesoderm, and lateral plate mesoderm.
-appear lateral to notochord
-occur in segmented pairs along length of embryo |
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Term
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Definition
-40 pairs
-each have three functional parts |
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Term
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Definition
| produce verebra and rib at each level |
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Term
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Definition
| form dermis of skin on dorsal part of body |
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Term
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Definition
| form skeletal muscles of neck, trunk, and limbs |
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Term
| intermediate mesoderm form... |
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Definition
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Term
| lateral mesoderm forms... |
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Definition
-dermis of skin in ventral region
-bones, ligaments, and dermis of limbs
-heart and blood vessels
-most connective tissues of body
-smooth muscle, connective tissue, and serosa of digestive and resp. organs |
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Term
| fetal alcohol syndrome (FAS) |
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Definition
| microcephaly, mental retardation, abnormal growth |
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Term
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Definition
| diffusible molecules that specify differentiation of a cell type at a specific location and/or direct migration of cells |
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Term
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Definition
-active form of vit. A
-"posteriorizes" the body: high conc. in embryo induce posterior structures to form |
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Term
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Definition
-family of proteins
-help establish dorsal/ventral patterns |
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Term
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Definition
-secreted glycoproteins
-determine cell polarity, proliferation, apoptosis, cell fate, and migration. |
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Term
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Definition
-important for early development
-early patterning, cell migration, differentiation
-ex. shh secreted by notochord: high conc. at floor of neural tube and low conc. at roof.
-high conc induces formation of interneurons and motor neurons: ventral neural patterning |
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Term
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Definition
-many dif altered phenotypes arise
-holoprosencephaly, digit malfunctions
-cyclopamine: investigative cancer treatments but a teratogen |
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Term
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Definition
| specifies fate of precursor cells, maintenance of stem cell populations |
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Term
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Definition
-activate or repress downstream genes to direct development
-usually end point of other signaling pathways
-eg. homeobox (hox), paired box (pax) |
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Term
| receptor tyrosine kinases |
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Definition
-growth factor signaling
-regulate cell proliferation, apop, migration
-growth of new blood vessels and axonal processes |
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