Term
|
Definition
process where a fertilized egg becomes a mature organism
-is continuous |
|
|
Term
| what does development begin with |
|
Definition
| fusion of oocyte with sperm to form a zygote |
|
|
Term
| what must happen to transform the zygote into a multicellular human being |
|
Definition
cell division
cell migration
cellular rearrangement
apoptosis
differentiation
growth
organogenesis |
|
|
Term
| what are the two major prenatal periods of development |
|
Definition
|
|
Term
| another name for the embryonic period. when does the embryonic period occur. purpose of this period. |
|
Definition
embryogenesis
first 8 weeks
single cell-->organ primordia |
|
|
Term
| when does the fetal period occur. what happens during this period |
|
Definition
9-birth
differentiation and body growth |
|
|
Term
| in what developmental period are the most visible changes |
|
Definition
|
|
Term
| why is the embryonic period susceptible to birth defects |
|
Definition
|
|
Term
| what controls developmental stages |
|
Definition
a group of proteins that give signals needed for normal development and growth of embryo
(differential gene expression=protein products for gene mediators of development) |
|
|
Term
| what do genes controlling for development encode |
|
Definition
different proteins for:
1-signalling molecules and their receptors
2-transcription factors
3-components of the extracellular matrix
4-enzymes |
|
|
Term
| how are genes encoding for development expressed |
|
Definition
| in combos of spatially and temporally patterns that control different processes |
|
|
Term
| what do mutations in genes for development cause |
|
Definition
|
|
Term
| does human development stop at birth |
|
Definition
|
|
Term
| when do most human developmental changes occur |
|
Definition
| before birth during embryonic and fetal periods |
|
|
Term
| human developmental periods |
|
Definition
| prenatal (embryonic & fetal) and postnatal |
|
|
Term
| what multi-step process converts germ cells genetically and phenotypically into mature gametes |
|
Definition
|
|
Term
|
Definition
| multi-step process converts germ cells genetically and phenotypically into mature gametes |
|
|
Term
| where does fertilization occur |
|
Definition
| in ampulla of uterine tube |
|
|
Term
|
Definition
|
|
Term
| where does embryo go after being fertilized |
|
Definition
| to uterus=implant in lining for nourishment |
|
|
Term
| what mediates fertilization and implantation |
|
Definition
|
|
Term
| what event ensures survival of any species |
|
Definition
|
|
Term
| products of gametogenesis |
|
Definition
|
|
Term
| name for gamete maturation |
|
Definition
men=spermatogenesis
women=oogenesis |
|
|
Term
| effect of gametogenesis on chromosome number and morphology |
|
Definition
chromosome number is cut in half
(46/diploid-->23/haploid)
morphological alterations |
|
|
Term
| whats spermatogenesis. where does it occur. when does it start |
|
Definition
process where spermatogonia-->spermatozoa (mature)
-in testes
-starts at puberty and continues for life |
|
|
Term
| at birth, whats recognized in testes by their large size and color |
|
Definition
|
|
Term
|
Definition
1-spermatogonia divide by mitosis
2-spermatocytes undergo meiosis=haploid cells/spermatids that develop into mature sperm |
|
|
Term
| name for the haploid gametes produced by spermatogenesis |
|
Definition
|
|
Term
| whats oogenesis. where does it occur. when does it start |
|
Definition
oogonia-->mature oocytes
-in ovaries
-begins before birth, completed after puberty |
|
|
Term
| when do oogonia undergo intensive mitotic activity |
|
Definition
| 2nd-5th month of pregnancy |
|
|
Term
|
Definition
1-oogonia=mitosis during 2nd-5th month of pregnancy
2-primary oocytes begin meiosis and arrest after meiosis I
-remain in meiosis I until puberty
3-fertilization=2nd meiotic division |
|
|
Term
| after fertilization, is cytoplasm retained by fertilized oocyte |
|
Definition
|
|
Term
| what makes it true to say that females are born with all the primary oocytes they will ever have |
|
Definition
| there are no more mitotic divisions after birth |
|
|
Term
| size and motility of secondary oocyte |
|
Definition
|
|
Term
| stage that secondary oocytes are arrested at |
|
Definition
|
|
Term
| what are secondary oocytes surrounded by after being released by the ovary |
|
Definition
|
|
Term
| what part of sperm contains haploid nucleus |
|
Definition
|
|
Term
| function of tail of sperm |
|
Definition
| motility for transport to site of fertilization |
|
|
Term
| discuss acrosome of sperm |
|
Definition
| enzyme-filled structure for fertilization process |
|
|
Term
| uterine tube plays important role for: |
|
Definition
1-gamete movement
2-preparation of sperm for fertilization
3-fertilization
4-development and transport of early embryo |
|
|
Term
| what happens when sperm enter uterine tubes |
|
Definition
they are collected in isthmus area and bind to tubal epithelium=induced by secretion of tube to undergo a capacitation reaction
(prepare sperm for being capable of fertilization) |
|
|
Term
| how long does the fertilization process take |
|
Definition
|
|
Term
| how are capacitated sperm guided to the oocyte in the ampulla of the uterine tube |
|
Definition
| cumulus cells and oocytes produce chemoattractants |
|
|
Term
|
Definition
1-sperm crosses layer of follicular cells by acrosome enzyme action and help from tail
2-penetration of zona pellucida, mediated by acrosome enzymes
3-plasma cell membranes of oocyte and sperm fuse
4-2nd oocyte meiotic division completes
5-sperm tail degenerates and gamete nuclei fuse |
|
|
Term
| when is penetration of a 2nd sperm prevented |
|
Definition
| after one penetrates the oocyte cytoplasm |
|
|
Term
|
Definition
|
|
Term
| what happens immediately after fusion of egg and sperm to form a zygote |
|
Definition
| series of mitotic divisions to increase cell number and decrease size of cells (blastomeres) |
|
|
Term
| cell stages during cleavage and implantation and characteristics of each and when they happen |
|
Definition
1-blastomeres (increase number, decrease size)-day 0
2-early morula (12-16 blastomeres)-day 3
3-late morula (reach uterine lumen, cells=compact)-day 4
4-blastula-4 and 1/2 to 5 days
5-blastocyst stage (cavity surrounded by cells)-day 8
6-implantation-day 7-12 |
|
|
Term
| what happens overall during cleavage and implantation |
|
Definition
| fertilized egg divides to form a compact cell ball, then the embryo implants into endometrial wall of uterus |
|
|
Term
| when does implantation occur and where |
|
Definition
| 7-12 days after fertilization in endometrial wall of uterus |
|
|
Term
|
Definition
1-inner cell mass
2-internal cavity/blastocyst cavity
3-outer layer of cells/trophoblast |
|
|
Term
| what happens during the blastocyst stage |
|
Definition
1-dissolution of zona pellucida signals that embryo is ready for implantation
2-preparation and coordination by embryo and endometrium for implantation
3-hormonal prep of endometrium to provide cellular and nutritional support to embryo |
|
|
Term
| what does the trophoblast differentiate into after penetration of uterine epithelium. what do the cells of the ICM differentiate into |
|
Definition
trophoblast differentiates into syncytiotrophoblast and cytotrophoblast
ICM cells differentiate into hyphoblast (small, cuboidal) and epiblast (columnar) cells |
|
|
Term
| what is the "decidual reaction" |
|
Definition
| cellular changes of endometrial in prep for implantation |
|
|
Term
| how long after fertilization does it take for the embryo to be completely embedded in the endometrium |
|
Definition
|
|
Term
| after implantation, what develops to support and protect the developing embryo |
|
Definition
| extraembryonic structures |
|
|
Term
|
Definition
| implantation in abnormal site (% has increased in recent years) |
|
|
Term
| what major event occurs during weeks 2 and 3 of development |
|
Definition
|
|
Term
| what happens during gastrulation |
|
Definition
inner cell mass gives rise to 3 germ layers:
(cellular arrangement=blueprint for embryo)
-ectoderm (outer)
-mesoderm
-endoderm (inner)
[bilaminar/2 cell types--->trilaminar/3 cell types] |
|
|
Term
| what is gastrulation characterized by/dominated by |
|
Definition
cell and tissue movements--cells are rearranged to have new positions and neighbors
-dominated by cell migration |
|
|
Term
| whats the basis for giving the name chordata to all vertebrae |
|
Definition
|
|
Term
| whats a notochord. whats its location |
|
Definition
| cellular structure along longitudinal axis of the embryo, located ventral to the neural tube |
|
|
Term
| what is the notochord formed from |
|
Definition
| cells that migrate cranially along the axis, acquiring mesodermal cell fate=these cells form a midline cellular cord called the notochordal process. this process acquires a lumen to form the notochord |
|
|
Term
| what end of the notochord forms first, then what |
|
Definition
| cranial end forms first, caudal end=added later |
|
|
Term
| another name for neural tube formation |
|
Definition
|
|
Term
| what is created after cells of notochord separate from the endodermal layer and form a definitive notochord |
|
Definition
| a solid rod of cells in the midline between the embryonic ectoderm and endoderm |
|
|
Term
what germ layers undergo:
-neurulation and nervous sytem development
-cranial nerve development
-head, neck, tooth development |
|
Definition
|
|
Term
| whats a significant event in establishment of body form during neurulation and pharyngeal arch development |
|
Definition
| folding of the flat trilaminar embryo into a cylindrical embryo |
|
|
Term
| when is neurulation completed |
|
Definition
|
|
Term
|
Definition
forming neural tube by:
1-form neural plate
2-general neural folds
3-close folds to form neural tube |
|
|
Term
| where does closure of neural tube start |
|
Definition
| at somite region--spreads cranially and caudally |
|
|
Term
| are the spinal cord and brain recognizable before closure of neuropores |
|
Definition
|
|
Term
| are fundamental sections of brain (midbrain, forebrain, hindbrain) manifested before closure of neuropores |
|
Definition
|
|
Term
| when does neurulation take place |
|
Definition
|
|
Term
| after 4th week/day 28, what region of neural tube is left with pores |
|
Definition
| anterior and posterior points for neuropores |
|
|
Term
| when the neural tube closes, whats formed |
|
Definition
CNS
-caudal=spinal cord
-cranial=brain vesicles |
|
|
Term
| whats the marked force in shaping the early nervous system |
|
Definition
| bending of cephalic end of embryo in the C shape |
|
|
Term
| what is the bending of the cephalic end of the embryo associated with |
|
Definition
| appearance of prominent cephalic flexure/bend of the brain at the level of the midbrain |
|
|
Term
| what happens at the 5th week |
|
Definition
| the cervical flexure appears at the boundary between the hindbrain and spinal cord |
|
|
Term
| whats the neural crest sometimes called and why |
|
Definition
| the "fourth germ layer" because it helps with formation of many body systems |
|
|
Term
|
Definition
| a flattened mass of cells that separates the neural tube from the dorsal ectoderm into right and left parts that shift to the dorsal lateral sides of the neural tube |
|
|
Term
| what structures do the neural crest cells help make |
|
Definition
ganglia and neurons
connective tissue components in head
pigment cells
craniofacial skeleton |
|
|
Term
| what do neural crest cells that migrate from the hindbrain/rhombencephalon aid in, what happens |
|
Definition
development of the face and pharyngeal arch system
-1st stream of cells mix with mesencyme cells beneath the forebrain to form connective tissue for facial development
-2nd stream of cells is incorporated in the first pharyngeal arch |
|
|
Term
| when do pharyngeal arches begin formation |
|
Definition
| during 4th week of development |
|
|
Term
| how many pharyngeal arches are there, what are they separated by |
|
Definition
| 6, separated by pharyngeal grooves externally and pharyngeal pouches internally |
|
|
Term
| what are the pharyngeal arches made of |
|
Definition
|
|
Term
| whats the mesencymal core of the pharyngeal arches derived from |
|
Definition
| mesoderm and neural crest |
|
|
Term
| what covers the mesenchyme core of the pharyngeal arches |
|
Definition
ectoderm externally
endoderm internally |
|
|
Term
| components of each pharyngeal arch |
|
Definition
-nerve component
-cartilaginous component
-muscular components
-arterial component |
|
|
Term
| what do the pharyngeal arches support |
|
Definition
|
|
Term
| what forms as a result of surface ectoderm invagination |
|
Definition
| stomodeum (where mouth will be) |
|
|
Term
| during early embryogenesis, how is the stomodeum sealed off from the primitive gut tube |
|
Definition
oropharyngeal membrane
(this breaks down by the end of the 1st month of gestation to bring the pharynx and foregut into communication with amniotic cavity |
|
|
Term
| what does the 1st pair of pharyngeal arches form |
|
Definition
|
|
Term
| portions of 1st pair of pharyngeal arches and where they extend |
|
Definition
top=maxillary prominence--extends beneath region of eye
bottom=mandibular prominence |
|
|
Term
| what does the ECTOdermal lining of 1st pharyngeal arch give rise to |
|
Definition
|
|
Term
| what does the maxillary process of the 1st pharyngeal arch give rise to and how |
|
Definition
maxilla
zygomatic bone
part of temporal bone
--by membranous ossification |
|
|
Term
| what does the mandibular process of the 1st pharyngeal arch have, what does it do |
|
Definition
| Meckel's cartilage-eventually disappears, except for 2 small parts at its dorsal end that stay to form the ear bones |
|
|
Term
| what do muscles from the 1st pharyngeal arch give rise to |
|
Definition
muscles of mastication
mylohyoid
tensor tympani
tensor palatini |
|
|
Term
| what nerve supplies muscles derived from the 1st pharyngeal arch |
|
Definition
| mandibular branch of trigeminal--V3 |
|
|
Term
| what provides sensory supply to the skin of the face |
|
Definition
opthalmic, maxillary, mandibular branches of trigeminal
--CN5 |
|
|
Term
| another name for 2nd pharyngeal arch |
|
Definition
|
|
Term
| what does the 2nd pharyngeal arch contribute formation to |
|
Definition
|
|
Term
| what does cartilage from the 2nd pharyngeal arch give rise to |
|
Definition
| stapes, stylohyoid ligament, lesser horn of hyoid bone, upper part of hyoid bone |
|
|
Term
| what do muscles from the 2nd pharyngeal arch give rise to |
|
Definition
| muscles of factial expression |
|
|
Term
| what nerve is derived from 2nd pharyngeal arch, what does it supply |
|
Definition
| facial nerve/CN7--supplies muscles of facial expression (also derived from 2nd arch) |
|
|
Term
| what does cartilage of the 3rd pharyngeal arch produce |
|
Definition
| lower part of body and greater horn of hyoid bone |
|
|
Term
| what muscles are derived from 3rd pharyngeal arch |
|
Definition
|
|
Term
| what nerve is derived from 3rd pharyngeal arch |
|
Definition
| glossopharyngeal nerve (innervates stylopharyngeus muscle from this arch too) |
|
|
Term
| what do cartilaginous components of the 4th and 6th pharyngeal arches do and what do they form |
|
Definition
| fuse to form thyroid and cartilage of larynx |
|
|
Term
| what muscles are derived from the 4th pharyngeal arch, innervation |
|
Definition
-cricothyroid--innervated by superior laryngeal branch of vagus
-levator veli palatini--by pharyngeal branch of vagus
-pharyngeal constrictors--by pharyngeal branch of vagus |
|
|
Term
| what muscles are derived from 6th pharyngeal arch, innervation |
|
Definition
| intrinsic laryngeal muscles--by recurrent laryngeal branch of vagus |
|
|
Term
| how many pairs of pharyngeal pouches are there |
|
Definition
|
|
Term
| what does the epithelial ENDOdermal lining of pouches give rise to |
|
Definition
different head and neck structures:
-1st pouch=middle ear cavity and auditory tube
-2nd=palatine tonsils
-3rd=dorsal part=inf parathyroid gland & ventral=thymus
-4th=dorsal part=sup parathyroid gland
-5th/part of 4th=ultimobranchial body (incorporated into thryoid gland to form parafollicular/C cells |
|
|
Term
| another name for pharyngeal grooves |
|
Definition
|
|
Term
| how many pharyngeal grooves/clefts are in the head and neck area |
|
Definition
|
|
Term
| what do pharyngeal grooves separate |
|
Definition
| separate arches externally |
|
|
Term
| what pharyngeal groove/cleft persists postnatal and contributes to structure of ear canals |
|
Definition
|
|
Term
| what do 2nd, 3rd, and 4th pharyngeal grooves form, why |
|
Definition
| temporary cavity/cervical sinus because 2nd pharyngeal arch is overgrowing the 3rd and 4th to fuse with the epicardial ridge |
|
|
Term
| where do pharyngeal membranes form |
|
Definition
| where epithelia of the grooves and pouches approach each other |
|
|
Term
| what pair of pharyngeal membranes contributes to formation of and adult structure, what is it |
|
Definition
| 1st pair--tympanic membrane/eardrum |
|
|
Term
| what frequency do we see craniofacial abnormalities |
|
Definition
|
|
Term
| abnormalities from pharyngeal arches, jaw, palate develop during: |
|
Definition
| first 2 months of embryonic development |
|
|
Term
| anomaly involving 1st pharyngeal arch, what is it |
|
Definition
| treacher collins syndrome--genetic disorder with hypoplasia of mandible and facial bones |
|
|
Term
| what is the first endocrine gland to develop |
|
Definition
|
|
Term
| how does the thyroid gland first appear |
|
Definition
| an epithelial growth from ENDOderm floor of the pharynx between 1st and 2nd pharyngeal pouches |
|
|
Term
| when and where do the facial primordia appear |
|
Definition
| early 4th week around the stomodeum |
|
|
Term
| how is facial morphogenesis regulated |
|
Definition
| organized signals from endoderm, ectoderm, and brain that affect pattern of neural crest derived mesenchyme |
|
|
Term
| how many facial primordia appear as prominences around the stomodeum, what are they |
|
Definition
5
-frontonasal process
-paired maxillary processes
-paired mandibular processes |
|
|
Term
| what are facial prominences produced by and when |
|
Definition
| expansion of neural crest cells that orginate from brain area during 4th week |
|
|
Term
| development of face: what happens during week 5 |
|
Definition
1-maxillary prominences enlarge and grow medially toward each other (mesenchyme proliferation)
2-bilateral ectodermal thickening, called nasal placodes appear on the frontonasal prominence
3-mesenchyme of facial structure is invaded by the muscles derived from the pharyngeal arches
4-muscles of mastication develop from 1st arch and is innervated
5-muscles of facial expression develop from 2nd arch and are innervated by facial nerve |
|
|
Term
| what does the mesenchyme around the nasal placodes form |
|
Definition
| medial and lateral nasal processes |
|
|
Term
| what do medial nasal processes do after formation |
|
Definition
| move towards each other and merge to form an intermaxillary segment |
|
|
Term
| what is the upper lip formed by |
|
Definition
| fusion of maxillary prominences with lateral nasal and medial prominences (studies=just max processes) |
|
|
Term
| what separates each maxillary prominence from the lateral nasal prominence |
|
Definition
|
|
Term
| what happens to the ectoderm at the floor of the nasolacrimal groove |
|
Definition
| it canalizes to form the nasolacrimal duct |
|
|
Term
|
Definition
| lateral merging of maxillary and mandibular processes (determines width of mouth) |
|
|
Term
|
Definition
| mandibular prominences merge in midline |
|
|
Term
| describe philtrum formation |
|
Definition
| medial nasal prominences become positioned and covered by the maxillary prominences |
|
|
Term
| development of face: what happens in week 6 |
|
Definition
1-nasal pits deepen by proliferation of mesenchyme and lead to formation of the nasal sac
2-nasal sacs grow dorsally |
|
|
Term
| specific morphology of the facial skeletal elements is determined by: |
|
Definition
signals from:
pharyngeal endoderm-->facial ectoderm=induce neural crest that form facial bones |
|
|
Term
what does the tongue develop from and when
-what are the specific components present and where do they originate |
|
Definition
4th week=mesenchymal swellings covered with ectoderm and endoderm on the floor of pharynx
-2 lateral lingual swellings
-1 medial swelling
(swellings originate from 1st pharyngeal arch) |
|
|
Term
| when and how do taste buds develop |
|
Definition
| weeks 11-13 by inductive signals to the epithelial cells of tongue |
|
|
Term
| what does the palate form from and when, where is/are this/these derived from |
|
Definition
week 9= 2 primordia: primary palate (from intermaxillary segment) and secondary palate (formed by 2 palatine processes from the maxillary prominences)
*fusion of the primary and secondary palate form the palate |
|
|
Term
| how do palatine processes grow |
|
Definition
| obliquely and downwards on each side. later in development (week 9) they elevate and fuse with the primary palate and with each other |
|
|
Term
| what are cleft lip and palate classified based on |
|
Definition
| developmental features with the incisive foramen as the dividing landmark |
|
|
Term
| what leads to incomplete cleft lip |
|
Definition
| partial or incomplete lack of fusion of maxillary prominence with the medial nasal prominence on one or both sides |
|
|
Term
| what leads to bilateral cleft lip/palate |
|
Definition
| failing of both maxillary prominences to meet and unite with both medial nasal prominences |
|
|
Term
| how and when do teeth develop |
|
Definition
*arise from oral epithelium and underlying mesenchyme derived from neural crest cells
-week 6=dental lamina forms and gives rise to dental buds |
|
|
Term
| do crowns of teeth grow after eruption |
|
Definition
|
|
Term
| what gives rise to periodontal ligament |
|
Definition
| mesenchyme outside cementum |
|
|
Term
|
Definition
| differentiated mesenchymal cells on outside of tooth produce a thin layer of specialized bone |
|
|
Term
| when are tooth buds for permanent teeth formed |
|
Definition
| 3rd month of development--remain dormant until 6th year of postnatal life |
|
|
Term
| ectoderm gives rise to the neural tube...what is formed from the neural tube |
|
Definition
brain
neural pituitary
spinal cord
motor neurons
retina |
|
|
Term
| differentiation of neural tube into various regions of the CNS occurs in these 3 levels: |
|
Definition
1-anatomical
2-tissue
3-cellular |
|
|
Term
| what happens in the tissue level of neural tube differentiation |
|
Definition
| different cellular organization of neural tube forms the different functional regions of the brain and spinal cord |
|
|
Term
| what happens in the cellular level of neural tube differentiation |
|
Definition
| neuroepithelial cells differentiate into the different types of nerve cells (neurons or glia) |
|
|
Term
| what inhibits formation of neural tissue and where is it found |
|
Definition
| signaling molecules (bone morphogenetic proteins) in the dorsal ectoderm |
|
|
Term
| what allows ectoderm to form the neural plate |
|
Definition
| induction of neural tissue (negative signal)=inhibits BMPs |
|
|
Term
| what does the first induction of the nervous system lead to |
|
Definition
| formation of a thickened ectodermal neural plate overlying the notochord |
|
|
Term
| what is the morphological manifestation of the earliest stages in establishing the nervous system |
|
Definition
|
|
Term
| steps to form early spinal cord |
|
Definition
1-induction events=thickened neural plate and neural tube are organized into a pseudostratified epithelium
2-nuclei appear in several layers within elongated neuroepithelial cells
3-nuclei shift position in cytoplasm of neuroepithelial cells |
|
|
Term
| true/false: neuroepithelial cells are highly mitotic |
|
Definition
|
|
Term
| true/false: theres a high correlation between nuclei position within neural tube and their stage of mitotic cycle...discuss |
|
Definition
true: S phase of DNA synthesis occurs when nuclei are near basal membrane (external limiting membrane)
-nuclei migrate within cytoplasm to apical surface and prepare for mitosis
-near lumen=mitotic division |
|
|
Term
| in spinal cord formation, daughter cells close to apical surface: |
|
Definition
| migrate slowly and remain as progenitor cells that are capable of mitosis |
|
|
Term
| in spinal cord formation, daughter cells near the basal surface: |
|
Definition
| move fast away from apical surface/lumen as a post-mitotic neuroblast |
|
|
Term
| whats a useful example to study features and organization of neural tube and why |
|
Definition
| spinal cord--maintains its fundamental organization through much of development |
|
|
Term
| in organization of developing neural tube, what is the layer closest to the lumen called, what does it consist of |
|
Definition
| ventricular zone-consists of epithelial cells (some are mitotic and become ependyma) |
|
|
Term
|
Definition
| columnar epithelium that lines the central canal of the CNS |
|
|
Term
| in the organization of the developing neural tube, what zone contains the cell bodies of the differentiating post-mitotic neuroblasts |
|
Definition
|
|
Term
| in organization of developing neural tube, neuroblasts continue to differentiate and form ____________ that contains neuronal processes but NOT ____________ |
|
Definition
forms PERIPHERAL MARGINAL ZONE that contains neuronal processes
BUT DOES NOT contain CELL BODIES |
|
|
Term
| as the spinal cord matures, the mantle zone becomes _________ and the marginal zone becomes ________ |
|
Definition
mantle/intermediate= gray matter (cell bodies)
marginal=white matter (cell processes) |
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Term
| as the spinal cord matures and the basic layers are established, several topographical features are recognized in the cord cross section: |
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Definition
1-division of cord into a DORSAL ALAR PLATE and a VENTRAL BASAL PLATE by the SULCUS LIMITANS within the central canal
2-a thin ROOF PLATE connects the left and right alar plates dorsally
3-a FLOOR PLATE that connects the two basal plates |
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Term
| in the spinal cord, what connects the two ventral basal plates |
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Definition
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Term
| in the spinal cord, what connects the left and right alar plates dorsally |
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Definition
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Term
| what divides the spinal cord into a dorsal alar plate and ventral base plate within the central canal |
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Definition
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Term
| in the spinal cord, what represents the motor component |
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Definition
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Term
| where in the basal plate are the gray matter with neurons |
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Definition
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Term
| axons that exit from the ventral horn of the spinal cord are: |
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Definition
| ventral motor roots of the spinal nerves |
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Term
| what forms the sensory area of the spinal cord |
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Definition
| alar plate gray matter=dorsal horn |
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Term
| how do sensory axons from the neural crest-derived ganglia enter the spinal cord |
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Definition
| as dorsal roots and synapse with neurons in the dorsal horn |
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Term
| whats the small area of gray matter between the dorsal and ventral horns, what does it contain |
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Definition
| lateral horn/intermediolateral gray column--contains cell bodies of autonomic neurons |
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Term
| when does brain development begin |
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Definition
| 3rd week of gestation and extends through late adolescence |
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Term
| at the end of the embryonic period, what structure of the brain are established and defined |
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Definition
rudimentary structures are established
major compartments of the CNS are defined |
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Term
| during what period is there rapid growth and elaboration of both cortical and subcortical structures of the brain |
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Definition
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Term
| early in development, before the posterior end of the neural tube closes, the anterior end undergoes drastic changes: |
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Definition
-neural tube balloons into 3 primary vescicles
-when posterior end closes, secondary bulges appear |
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Term
| what do neural crest cells above each rhombomere form |
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Definition
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Term
| what are neuromere segments in the hindbrain called and what do they form |
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Definition
| rhombomeres form cranial nerves |
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Term
| what are neuromere segments in the forebrain called and what do they form |
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Definition
prosomeres from the midbrain-forebrain boundary to the tip of the forebrain and are incorporated into the diencephalon to form the thalamus
(contribute to diencephalonic and telencephalonic structures...also form some cranial nerves) |
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Term
| what cranial nerves are formed from the forebrain/prosomeres |
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Definition
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Term
| what cranial nerves form from primitive ventral roots |
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Definition
| CN 3, 4, 6, 7 motor nerves |
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Term
| rhombomeres give rise to motor nuclei of CN: |
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Definition
| CN 5, 7, 9, 10 (mixed nerves with motor and sensory components--each nerve supplies derivatives of a different pharyngeal arch) |
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Term
| ectoderm derived from neural crest cells extends throughout the length of the neural tube and migrates laterally to give rise to: |
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Definition
sensory/dorsal root ganglia
(also differentiate into SYMP neuroblasts, Schwann cells, pigment cells, etc.) |
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Term
| peripheral nerves are myelinated by_________. each cell myelinates ______ axon/s |
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Definition
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Term
| where do Schwann cells originate from and whats their relationship with axons |
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Definition
| originate from neural crest and wrap around axons |
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Term
| fibers in the spinal cord are myelinated by ___________. each cell myelinates ________ axon/s |
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Definition
oligodendrocytes
up to 50 axons |
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Term
| neuroblasts of the dorsal ganglia form _____ processes: |
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Definition
2:
-penetrate dorsal sensory root of the spinal nerve and penetrate to one of the brain centers
-peripherally growing processes penetrate ventral motor roots that form trunk of spinal nerve and terminate in sensory receptor organs |
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