Term
2nd Pharyngeal Arch
Nerve
Muscles
Bones |
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Definition
CN VII Facial
Muscles of facial expression
stapedius
stylohyoid
digastric
Stapes
Styloid Process
Hyoid |
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Term
3rd Pharyngeal Arch
Nerve
Muscles
Bones |
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Definition
CN IX Glossopharyngeal
styloharyngeus
Hyoid |
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Term
1st Pharyngeal Arch
Nerve
Muscles
Bones |
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Definition
CN V (trigeminal)
Muscles of mastication
tensor tympani
digastric
Malleus
Incus |
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Term
4th and 6th Pharyngeal Arch
Nerve
Muscles
Bones |
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Definition
Vagus CN X
larynx/esophogeal muscles
cartilage |
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Term
Tongue Innervation
Sensory |
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Definition
anterior 2/3 CN V (V3-Mandibullar)
Posterior 1/3 CN IX |
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Term
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Definition
anterior 2/3 CN VII
posterior 1/3 CN IX
small part CN X |
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Term
| Motor innervation of tongue |
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Definition
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Term
| Congenital lingual cysts and fistulas |
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Definition
cysts: remnants of the throglossal duct
fistula: persitance of lingual parts of thyroglossal duct open through the foramen cecum into oral cavity |
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Term
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Definition
"tongue tie"
lingual frenulum is short and connects inferior surface of tongue to floor of mouth, interferes with protrusion |
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Term
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Definition
large tongue
lymph tumor or muscular hypertrophy |
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Term
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Definition
| small tongue due to underdeveloped mandible, recession of chin |
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Term
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Definition
bifid or cleft tongue
incomplete fusion of tongue |
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Term
Congenital Megacolon
inheritance |
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Definition
incomplete penetrance and variable expressivity
RET proto-oncogene
1 in 5000 newborns |
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Term
Congenital Megacolon
presentation |
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Definition
absence in ganglion cells
lack autonomic ganglion cels in myenteric plexus
dilated colon due to failure of colon to relax
lacks PNS innervation |
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Term
Congenital megacolon
embryological cause |
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Definition
failure of neural crest cells to migrate to wall of colon during the 5th and 7th week
failure of PNS ganglion to develop in Auerbach and Meissner plexuses |
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Term
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Definition
| protective case for the brain |
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Term
| cartilaginous neurocranium |
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Definition
cartilaginous base of the developing cranium, forms from several cartilages
ossification sequence: occipital bone→body of sphenoid→ ethmoid bone |
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Term
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Definition
| ossification of mesenchyme at the sides and top of the brain forms the calvaria (cranial vault); calvaria are separated by sutures; sutures meet at 6 large fibrous fontanelles; |
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Term
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Definition
most mesenchyme derived from neural crest migrate into pharyngeal arches and form the craniofacial structures (HOX genes regulates this)
ossification in the maxillary prominence of 1st PA |
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Term
Nonclosure of the neural tube
-how many sites are there |
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Definition
| 5 closure sites in the formation of the neural tube |
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Term
Nonclosure of
Site 1
Site 2 |
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Definition
Site 1: spina bifida cystica
Site 2: mero/anencephaly
Site 2,4,1: craniorachischisis
Site 3 nonfusion is rare |
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Term
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Definition
Too few cervical vertebral bodies
short neck, low hairline, restricted movements |
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Term
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Definition
| failure of the halves of the embryonic neural arch to fuse; 80% of cases are “open” and are covered by a thin membrane |
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Term
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Definition
closed, covered by skin
failure of the halves of the neural arch to fuse
L5 or S1
usually in first sacral vertebrae |
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Term
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Definition
severe, involving spinal cord and meninges
protrusion of spinal cord/meninges through defects in the vertebral arches
-assoc cyst like sac |
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Term
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Definition
most commonly lumbar rib
result from the development of the costal processes of vercial or lumbar vertebrae
pressure on brachial plexus of nerves in neck and axilla can cause neurovascular symptoms (paralysis, anesthesia of upper limb) |
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Term
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Definition
fusion of ribs
posteriorly when two or more arise from a single vertebra |
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Term
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Definition
Results in scoliosis
Failure of one of the chondrification centers to appear and failure of half of vertebrae to form |
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Term
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Definition
cleft vertebral column
various disorders that primarily affect axial structures
neural folds fail to fuse for variety of reasons (idiopathic, teratogenic) |
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Term
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Definition
-Pes excavatum: concave depression of lower sternum due to overgrowth of costal cartilages
-minor clefts
-sternal foramen at the junction of 3rd and 4th sternebrae due to incomplete fusion of the cartilaginous sternal bars whilst embryo |
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Term
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Definition
calvaria is absent and extensive defects of vetebral column
-mero/anencephaly 1 in 1000 is fatal
-failure of cranial end of neural tube to close during 4th week = no calvaria |
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Term
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Definition
prenatal closure of sutures
Msx2 and Alx4 mutations have been implicated |
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Term
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Definition
sagittal suture closes early
cranium is long, narrow and wedge shaped |
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Term
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Definition
premature closure of the coronal suture
high, tower like cranium |
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Term
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Definition
coronal suture closes on one side prematurely
cranium is twisted and asymmetrical |
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Term
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Definition
premature closure of the frontal suture
deformity of the frontal bone and other anomalies |
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Term
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Definition
Brain and cranium fail to grow due to abnormal development of the CNS
fontanelles close early, have small calvaria
mental retardation |
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Term
| Anomalies at the Craniovertebral Junction |
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Definition
basilar invagination: displacement of bone around foramen magnum
assimilation of the atlas: atlas and occipital bone aren't separated |
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Term
| Development of the spinal cord |
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Definition
caudal to the 4th pair of somites forms the spinal cord
neural canal-->central canal by wk10 |
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Term
| Three zones of the developing Spinal Cord |
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Definition
1. Ventricular zone: ependymal layer, gives rise to neurons and glial cells
2. Marginal zone: outer part of epi, becomes white matter
3. Intermediate zone: forms neuroblasts that become neurons |
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Term
| Differentiation of neuroepithelium |
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Definition
from neuroepithelium three splits that lead to:
1.neurons
2. glioblasts
a.astrocytes
b. oligodendrocytes
3. epedyma |
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Term
| Development of the spinal meninges |
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Definition
mesenchyme that surround the neural tube condenses to form the meninges --> thickens to become the dura mater
leptomeninges (pia/arachnoid) is from neural crest cells |
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Term
| When does CSF begin to form |
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Definition
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Term
| Spinal ganglia development |
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Definition
Neural crest cells --> bipolar neuroblasts --> unipolar afferent neuron (spinal ganglion cell)
central processes enter the spinal cord and make up the dorsal roots of spinal nerves |
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Term
| PNS sensory cells derived from |
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Definition
all from neural crest cells
all nerve related stuff develops in week 5 |
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Term
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Definition
A skin dimple indicates the region of closure of the caudal neuropore
-last place of separation btw the surgace ectoderm and the neural tube
-dimple connected with the dura mater by a fibrous cord |
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Term
| Spina Bifida with meningocele |
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Definition
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Term
| Spina Bifida with meningomyelocele |
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Definition
spinal cord and or nerve roots included in the sac
-marked neurologic deficit inferior to sac
-covered by skin or easily ruptured membrane |
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Term
| High AFP is indicative of? |
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Definition
spina bifida
-in amniotic fluid or in maternal blood serum
-fetal vetebral column can be detected by ultrasound at 10-12 weeks |
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Term
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Definition
most severe type of spina bifida
-spinal cord is open because the neural folds failed to fuse
-spinal cord is a flattened mass of nervous tissue
-can be caused by local overgrowth of the neural plate --> caudal neuropore fails to close at the end of the 4th week |
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Term
Where does the spinal cord end in a 6 mo fetus?
Newborn?
Adult? |
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Definition
6 month fetus: S1
Newborn: 2nd or 3rd lumbar
Adult: L1 |
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Term
Myelination
which is myelinated first, motor/sensory?
When are nerve fibers myelinated? |
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Definition
Motor roots are myelinated before sensory roots. In general, fiber tracts become myelinated at the same time they become functional.
Approx 20 weeks (5mo) peripheral nerve fibers look white bc of myelin |
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Term
Origin of the Pituitary gland?
-Tissue types |
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Definition
Ectodermal in origin
-upgrowth from oral ectoderm = hypophysial diverticulum (Rathke's pouch)
-adenohypophysis (glandular part) or anterior lobe
-downgrowth from neuroectoderm = neurohypophysial diverticulum
-neurohypophysis (nervous part) |
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Term
Where does the pars anterior come from?
What about the pars tuberalis? |
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Definition
-the hypophysial diverticulum gives rise to the pars anterior
-the infundibular stem gives rise to the pars tuberalis |
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Term
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Definition
defects in the formation of the cranium
-usually in the median plane of the calvaria
-meninges herniate: cranial meningocele
-meninges and brain herniate: meningoencephalocele
-protruding brain contains venticular system: meningohydroencephalocele |
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Term
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Definition
| embryo brain exposed or extruding from the cranium --> nervous tissue undergoes degeneration |
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Term
| Agenesis of the Corpus Callosum |
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Definition
complete or partial absence of the corpus callosum
-seizures and mental deficiency
-50 different human congenital syndromes |
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Term
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Definition
significant enlargement of the head due to imbalance in CSF
-choroid plexus adenoma |
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Term
| congenital aqueductal stenosis |
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Definition
cerebral aqueduct is narrow or consists of several minute channels
-x linked recessive
-fetal viral infection (Toxoplasmosis gondii) |
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Term
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Definition
wide variety, defective formation of forebrain
-maternal diabetes, teratogens, alcohol
-destruction of embryonic cells in the 3rd week |
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Term
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Definition
cerebral hemispheres are absent
head grows excessively after birth due to accumulation of CSF
little or no cognitive development |
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Term
| Eye parts that come from the Neuroectoderm from the forebrain |
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Definition
| retina, posterior layers of iris, and optic nerve |
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Term
| Eye parts that come from the surface ectoderm |
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Definition
| forms lens and corneal epithelium |
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Term
| What part of the eye comes from the mesoderm between neuroectoderm and surface ectoderm? |
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Definition
| fibrous and vascular coats of eye (sclera and choroid) |
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Term
When does the retinal fissure close?
What happens if it doesn't? |
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Definition
6th week
Coloboma of the retina/iris |
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Term
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Definition
arrested development of the eye around the time the optic vesicle has formed in the 4th week
-underdeveloped eye and no lens
Can be genetic
Can be caused by virus, Toxoplasmos |
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Term
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Definition
Congenital absence of an eye
primary: no eye development after 4th week
secondary: forebrain suppressed |
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Term
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Definition
complete absence of the iris
-arrest of development at the rim of the optic cup at the 8th week |
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Term
| Persistent pupillary membrane |
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Definition
pupillary membrane persists
can lead to atresia of the pupil |
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Term
Persistence of the hyaloid artery
-what normally happens? |
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Definition
-normally degenerates as the proximal part becomes the central artery of the retina
-distal part persists, looks like a worm, can form a cyst, can lead to microphthalmic eye |
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Term
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Definition
no lens
failure of lens placode to form during the 4th week |
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Term
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Definition
abnormal elevation of intraocular pressure due to drainage issues
-abnormal development of the scleral venous sinus
-genetic or rubella |
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Term
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Definition
opaque lenses-->blindness
Rubella during 4th to 7th weeks when lens is developing
-radiation
-congenital galactosemia-->lack of an enzyme that leads to build up of milk and lens injury |
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Term
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Definition
increase in CSF pressure slows venous return from the retina and causes papilledma
-retinal vessels are covered by pia mater and lie in the subarachnoid space that surrounds the optic nerve |
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Term
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Definition
retarded dev of the levator palpebrae superious
-prenatal injury or dystrophy of CN III
-AD |
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Term
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Definition
| a notch in the upper eyelid (palpebral colobomas) |
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Term
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Definition
congenital absence of eyelids, skin covers the eye
eyeball is small and defective, no cornea or conjunctiva
AR |
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Term
| Which teratogen gives you: microcephally, cataracts, glaucoma, pigmented retinopathy |
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Definition
| Rubella infection early in pregnancy (4th week) |
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Term
| Which teratogen gives you craniofacial abnormaliites and NTD? |
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Definition
| Valproic acid and Isoretinoin (Retin A) |
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Term
| Which teratogen gives you microcephaly, microphthlamia, hydrocephaly, chorioretinitis, cerebral calcifications? |
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Definition
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Term
| What congenital malformations do you see in trisomy 21, 13, 18? |
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Definition
mental deficiency
severe CNS malformations
microphthalmia (13) |
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