Dental prenatal development
About this set
Created by:
Mlgeisler1 on September 1, 2011
Log in to favorite or report as inappropriate.
Order by
30 terms
Terms | Definitions |
|---|---|
 Embryology | Study of prenatal Dev. |
| Prenatal Dev. consist of 3 periods: | Preimplantation period - 1st trimester Embryonic period - 1st trimester Fetal period - 2nd & 3rd trimester |
| Primordium | Earlist indication of a tissue/organ during prenatal dev. |
| Meiosis | the joining of the ovums chromosomes and the sperms |
| Mitosis | individual cell division |
| During the First week of the preimplantation period: | Fertilization occures in the fallopian tube then travels to the uterus, zygote "fertilized egg" undergoes mitosis while secretion of fluid by the cells w/i the morula, the zygote becomes a blastocyst |
| Trisomy 21: | meiosis faliure, chromosome #21 is present after meiotic division, example down syndrome |
| Ectopic pregnancy | implantation in the fallopian tube |
| What is the Trophoblast layer in the blastocyst? | prenatal support tissue |
| What is the Embyoblast layer in the blastocyst? | Embryo |
| Embryonic period | physiological processes which obbur during this period to change the blastocyst to an embryo: induction,proliferation,differentiation,morphogeneses,maturation |
| Induction | the action of one group of cells to influence the activity of another population of cells which is "competent" to respond. "cell phone analogy" |
| Proliferation | Controlled cellular growth with accompanying accumulation of cellular byproducts: interstitial growth "addition of outter layer",appositional growth "organs" |
| Differentiation | Cells which are identical genetically become quite different structurally and tunctionally;cells change their characteristics and establish a new population: Cytodifferentiation- cells Histodifferentiation- tissues Morphodifferentiation- shapes |
| Morphogeneses | Development of specific tissue morphology. "complex organisms" me vs fish |
| Maturation | attainmint of adult function and size due to proliferation, differentiation, and morphogenesis |
| During the second week "embryonic period" | Blastocyst cells form a bilaminar disc (circular disc of bilayered cells) Superior epiblast layer- columnar cells inferior hypoblast layer- cuboidal cells |
| After the creation of the epiblast/hypoblast layers the bilaminar disc is held in the uterus endometrium between 2 fluid filled cavities: | Amniotic cavity- faces epiblast layer (ectoderm) Yolk sac- faces hypoblast layer (endoerm) |
| Placenta develops from | interations of the trophoblast and endometrical tissues |
| In the third week "embryonic period" p26 | Primitive streak forms w/i the bilaminar disc, some epiblast layer cells "ectoderm" migrat along the streak and turn toward the hypoblast layer locate between the two layers to form a third layer = "mesoderm" |
| The Embryonic bilaminar disc turns into | Trilaminar disc |
| Trilaminar disc now has three layers | Ectoderm-mervous system Mesoderm-connective tissue "bone" Endoderm-glands & linings " respitory & digestive linings" |
| Once the trilaminar disc has three layers it also has ... membranes and ...ends | Caudal and cephalic ends oropharyngeal and cloacal membranes |
| Development of the CNS begins at the end of the 3 week | specialized group of cells turns ectoderm into neuroectoderm A band of cells extends from caudal to cephalic end This plate thickens and a groove invaginates centrally Groove deepens, ends meet, forms neural tube "spinal cord" |
| CNS development continued: Neural crest cells.. | Separate as neural tube fuses migrate cephalically and influence the mesodermal cells in the head and neck area that produce bone, cartilage, pulp, dentin, cimintum, and periodontal ligament.(migrating neuroectoderm) |
| Treacher Collins Syndrome p29 | Full facial development is prevented by an interference in the migratrion of neuroectoderm to the facial region. Manefesed by: drooped eyelids, malformed ears, hair growth |
| Ectodermal dysplasia | Abnormal dev. of one or more ectodermal structures. Hereditary etiology May manifest as abnormalities of teeth, skin, hair,nails,eyes,facial structure,glands |
| In the fourth week "embryonic period" | Disc undergoes folding into an embryo and tissues are placed in their proper positions for fruther dev. Defferentiation occurs mainly at cephalic end where brain is forming, protruding over the oropharyngeal membrane and cardiac area Embryo still has three layers Future GI tract formed by central tube |
| Developmental disturbances (teratogens) | Teratogens may have devastating effects during embryonic period: rubella virus alcohol fetal syndrome radiation Failure of fusion of neural tube= spina bifida |
| Fetal Period "9th week to 9th month" p38 | Period of maturation Newly formed tissues and organs begin to function Dev. disturbances during this period may result from amniocentesis systemic tetracycline |
First Time Here?
Welcome to Quizlet, a fun, free place to study. Try these flashcards, find others to study, or make your own.