Term
| what is the study of prenatal development called? |
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Definition
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Term
| What is the study of microscopic form, composition, and function of tissue that make up a living organism called? |
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Definition
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Term
| What week in development is the preimplantation period? what even ends this period? |
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Definition
| 1 week- ends when embryo implants |
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Term
| What weeks define the embryonic/prenatal period? |
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Definition
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Term
| What weeks define the fetal period? |
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Definition
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Term
| what is the resulting structure called when a egg and sperm unite? |
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Definition
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Term
| What period does the fertilization process take place? |
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Definition
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Term
| what is the mass of slightly differentiated cells that forms after fertilization called? |
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Definition
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Term
| what is the mass of fertilized cells called when it implants in the uterus? |
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Definition
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Term
| What is it called when an embryo implants outside of the uterus? |
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Definition
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Term
| What is the cellular layer of the uterus that contains blood vessels for nourishment of the embryo? |
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Definition
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Term
| which hormones control the thickening of the endometrium for implantation? |
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Definition
| estrogen and progesterone |
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Term
| When the blastocyst implants in the endometrium, what two layers make up the now hollow inner cell mass? |
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Definition
trophoblast layer
embryoblast layer |
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Term
| What is the role of the trophoblast layer in the implanted blastocyst? |
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Definition
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Term
| when do most developmental disturbances occur? |
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Definition
| 1st trimester (preimplantation--> embryonic period) |
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Term
| The amount of damage caused by developmental disturbances depends on timing. When is the MOST sensitive time during development? |
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Definition
| differentiation (embryonic 4-8 weeks) |
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Term
| Is a defect to a group of cells or organ system MORE damaging? |
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Definition
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Term
| What is another name for a birth defect? |
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Definition
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Term
| What are the two classes of developmental disturbance causes? |
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Definition
genetic factors/ chromosomal abnormalities
environmental factors (teratogen) |
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Term
| What is another term for environmental factors that can cause developmental disturbances? |
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Definition
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Term
| What are some examples of environmental factors/teratorgens in developmental disturbances? (4) |
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Definition
1. infections
2. drugs
3. chemicals
4. radiation |
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Term
| What are some examples of infections that cause Dev dist. |
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Definition
| rubella, herpes, HIV, syphilis |
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Term
| what are some examples of drugs that cause dev dist, |
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Definition
| tetracycline, dilantin, lithium, thalidomide |
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Term
| what is an example of a chemical that causes dev dist. |
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Definition
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Term
| what kind of radiation is linked to dev dist |
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Definition
| high levels of ionizing radiation |
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Term
| What is a chromosomal abnormality that occurs during prenatal/embryonic development? |
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Definition
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Term
| What about Down's syndrome is significant to dental care? |
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Definition
period and tooth abnormalities
poor tongue muscles
mental retardation
**usually see patients every 3 months |
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Term
| What are the 5 stages in prenatal development? |
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Definition
induction
proliferation
differentiation
morphogenesis
maturation |
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Term
| What defines the induction phase of prenatal development? |
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Definition
| interaction between cells |
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Term
| What two types of growth are occurring during the proliferation phase of prenatal development? |
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Definition
appositional growth
interstitial growth |
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Term
| Define the proliferation phase of prenatal development |
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Definition
| controlled cellular growth and accumulation of byproducts |
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Term
| What is growth deep within a tissue (soft tissues) |
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Definition
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Term
| What is tissue enlargement by additional layer on the outside (hard tissues) |
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Definition
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Term
| Define the differentiation phase of prenatal development |
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Definition
| change in identical embryonic cells to become distinct structurally and functionally. |
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Term
| What are the 3 different types of differentiation? |
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Definition
cytodifferentiation
histodifferentiation
morphodifferentiation |
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Term
| what type of differentiation causes different cell types to develop? |
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Definition
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Term
| What type of differentiation causes different tissue types to develop? |
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Definition
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Term
| What type of differentiation causes different forms to develop? |
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Definition
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Term
| What is the development of specific tissue morphhology or differing form due to cell migration and inductive interactions? |
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Definition
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Term
| What is the attainment of adult function and size due to proliferation, differentiation and morphogenesis? |
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Definition
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Term
| What week does the bilaminar embryonic disc develop? What developmental period is this? |
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Definition
| 2nd week - embryonic period |
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Term
| What two cells layers make up the bilaminar embryonic disc? |
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Definition
epiblast layer
hypoblast layer |
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Term
| What cavity does the epiblast layer face? what shape are the epiblast cells? |
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Definition
| amniotic cavity. columnar cells |
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Term
| What cavity does the hypoblast layer face? what shape are the hypoblast cells? |
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Definition
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Term
| During what week does the primitive streak develop is the bilaminar embryonic disc |
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Definition
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Term
| What causes the formation of the primitive streak? |
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Definition
| proliferation of cells in the midline of the bilaminar disc |
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Term
| What are two results of the primitive streak development? |
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Definition
1. creates bilateral symmetry (R/L)
2. creates 3rd layer of cells (mesoderm--> mesenchyme) |
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Term
| are the newly formed mesenchyme cells of the primitive streak differentiated into cell types? |
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Definition
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Term
| what cells will the mesenchyme become? |
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Definition
| embryonic CT: fibroblasts, chondroblasts, osteoblasts |
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Term
| What is the embryonic disc called once the third layer has been created? |
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Definition
| Embryonic trilaminar disc |
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Term
| What are the 3 germ layers that make up the trilaminar embryonic disc? |
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Definition
1. ectoderm
2. mesoderm
3. endoderm |
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Term
| What earlier cellular layer did the ectoderm develop from? |
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Definition
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Term
| what earlier cellular layer did the endoderm develop from? |
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Definition
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Term
| What structures will the ectoderm later form? (4) |
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Definition
epithelium lining or oral and nasal cavity
enamel
skin
brain and spinal cord |
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Term
| What structures will the mesoderm later form? (6) |
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Definition
muscle
skeleton
CT
BV
lymph cells & vessels
kidneys and other internal organs |
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Term
| What structure will the endoderm later form? |
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Definition
epithelial linings of the respiratory and digestive tract
genitourinary system |
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Term
| When does development of the CNS begin? |
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Definition
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Term
| What structure does the neural plate fold and fuse to form? |
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Definition
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Term
| What 3 primary brain vesicles form when the neural tube closes? |
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Definition
1. forebrain
2. midbrain
3. hindbrain |
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Term
| What two structures form the neuroectoderm? |
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Definition
neural plate
neural groove |
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Term
| What structures in the neural plate actually fuse to form the neural tube? |
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Definition
| neural folds (lateral edges of neural plate) |
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Term
| what region do the neural folds reach the midline? |
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Definition
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Term
| What tissue gives rise to somite cells? |
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Definition
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Term
| How many paired somites are there on each side of the CNS midline? |
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Definition
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Term
| What structures do the somites become? |
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Definition
skeletal structures of head and neck
muscles
dermis |
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Term
| During which week do the somites develop? |
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Definition
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Term
| After fusion of the neural tube, neural crest cells migrate and will eventually become which structures? |
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Definition
| pulp, dentin, cementum, alveolar bone, and PDL |
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Term
| which end of the embryo is more advanced throughout embryonic development? |
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Definition
| cephalic more advanced than caudal |
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Term
| During which week does the face start to develop and mouth begins to form? |
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Definition
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Term
| what is another name for the primitive mouth? |
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Definition
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Term
| The stomodeum forms from an invagination of which tissue? Where does this invagination form? |
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Definition
| ectoderm on the ventral side of the cephalic end |
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Term
| What two germ layers for the buccopharyngeal membrane? What structure do these germ layers belong to? |
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Definition
| ectoderm and endoderm from the foregut |
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Term
| During which week does the buccopharyngeal membrane rupture? |
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Definition
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Term
| What does the rupture of the buccopharyngeal membrane allow to occur? |
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Definition
| communication between the stomodeum and foregut |
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Term
| What is a developmental disturbance of the ectoderm? |
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Definition
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Term
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Definition
| abnormal tissue development |
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Term
| What is another term for ectodermal dysplasia and what causes it? |
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Definition
"little old man" syndrome
hereditary |
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Term
| What is the clinical presentation for ectodermal dysplasia? |
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Definition
abnormal development of the ectodermal structures (teeth, skin, hair, nails, eyes, facial structures, glands)
**for teeth- partial or complete anodontia |
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Term
| What are 4 common causes of developmental disturbances that occur in the embryonic period? |
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Definition
Rubella virus (german measles)
Syphilis
Fetal alcohol syndrome
Neural tube defects |
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Term
| What are the congenital malformations associated with Rubella? |
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Definition
cataracts
cardiac defects
deafness |
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Term
| What are the congenital malformations associated with Syphilis (treponema pallidum)? |
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Definition
defective molars/incisors
deafness
paralysis |
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Term
| What are the congenital malformations associated with fetal alcohol syndrome? |
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Definition
mental retardation
facial anomalies |
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Term
| What are the congenital malformations associated with Spina bifida (neural tube defects)? How is this prevented? |
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Definition
failure of fusion of the neural tube
folic acid supplements |
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Term
| When does the fetal period of prenatal development begin? |
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Definition
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Term
| What characterizes the activity during the 9th week (fetal period)? |
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Definition
maturation of existing structures
(some proliferation, differentiation, and morphogenesis) |
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Term
| What is a common developmental disturbance during the detail period of development? |
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Definition
| systemic tetracycline (staining can effect primary and sometimes permanent teeth) |
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Term
| What are two methods of detecting developmental disturbances during the fetal period? |
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Definition
-amniocentesis (sample of amniotic fluid)
-unltrasound |
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