Term
| Paraxial mesoderm is present in what form? |
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Definition
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Term
| What is formed by paraxial mesoderm? |
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Definition
| Posterior portions of the cranial base and cranial vault, skeletal muscles of the craniofacial region, dermis, connective tissue, and caudal meninges |
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Term
| What is formed by lateral plate mesoderm? |
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Definition
| Laryngeal cartilages and other connective tissues |
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Term
| What is formed by neural crest cells? |
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Definition
| Pharyngeal arches and some facial skeletal structures, sensory ganglia of CN V, VII, IX, and X |
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Term
| When do pharyngeal arches first appear? |
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Definition
| Fifth week of development |
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Term
| How many pairs of pharyngeal arches exist during development? |
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Definition
| Six though 5th is rudimentary or absent in humans |
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Term
| What separates the pairs of phayngeal arches? |
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Definition
| Externally by pharyngeal clefts and internally by pharyngeal pouches |
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Term
| What are the different components of each pharyngeal arch |
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Definition
| Skeletal, muscular, nervous, and arterial components |
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Term
| What makes up the first pharyngeal/mandibular arch? |
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Definition
| Maxillary process, mandibular process, stomodeum (joins fronotonasal prominence to form the face around the primitive oral cavity) |
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Term
| The cartilage of the first pharyngeal arch is known as what? |
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Definition
| Meckel's cartilage, also forms the malleus, incus, and anterior ligament of the malleus of the inner ear and the sphenomandibular ligament |
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Term
| What skeletal bones are formed by the first pharyngeal arch? |
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Definition
| Maxilla, premaxilla, zygomatic bone, and squamous part of the temporal bone |
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Term
| What muscles are formed by the first pharyngeal arch? |
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Definition
| Muscles of mastication, mylohyoid and anterior belly of the digastric, tensor veli palatini, and tensor tympani |
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Term
| What is the nerve of the first pharyngeal arch? |
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Definition
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Term
| Which branch of CN V (trigeminal n.) innervates the muscles derived from the first pharyngeal arch? |
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Definition
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Term
| What is the name of the cartilage derived from the second pharyngeal arch? |
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Definition
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Term
| Reichert's cartilage gives rise to what structures? |
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Definition
| Stapes, styloid process, stylohyoid ligament, and the lesser horn and upper part of the hyoid bone |
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Term
| What muscles are formed by the second pharyngeal arch? |
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Definition
| Muscles of facial expression (including buccinator), stylohoid, posterior belly of the digastric, and stapedius |
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Term
| What is the nerve of the second pharyngeal arch? |
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Definition
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Term
| What branch of CN VII (facial n.) carries taste from the anterior 2/3 of the tongue? |
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Definition
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Term
| What is formed by the cartilage of the third pharyngeal arch? |
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Definition
| Lower part of the body and greater horn of the hyoid bone |
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Term
| What muscles are derived from the third pharyngeal arch? |
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Definition
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Term
| What innervates the stylopharyngeus muscle? |
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Definition
| CN IX (glossopharyngeal n.) |
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Term
| Cartilage that forms the larynx is derived from which pharyngeal arches? |
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Definition
| 4th and 6th pharyngeal arches |
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Term
| What muscles are formed by the fourth pharyngeal arch? |
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Definition
| Muscles of the soft palate (excluding tensor veli palatini), muscles of the pharynx (excluding stylopharyngeus), and cricothyroid muscles of the larynx |
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Term
| What innervates soft palate and pharynx muscles formed by the fourth pharyngeal arch? What innervates the cricothyroid muscle? |
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Definition
| Pharyngeal branch of CN X (vagus n.) and external laryngeal branch of CN X (vagus n.) respectively |
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Term
| What muscles are formed by the sixth pharyngeal arch? |
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Definition
| Intrinsic muscles of the larynx (excluding cricothyroid) |
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Term
| What innervates the muscles formed by the sixth pharyngeal arch? |
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Definition
| Recurrent larungeal branch of CN X (vagus n.) |
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Term
| Outpocketings of the pharyngeal wall internally separating pharyngeal arches are known as what? |
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Definition
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Term
| What is another name for the first pharyngeal pouch? |
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Definition
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Term
| What is formed by the first pharyngeal pouch? |
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Definition
| Primitive tympanic cavity and auditory (Eustachian) tube, contributes to tympanic membrane |
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Term
| What is formed by the second pharyngeal pouch? |
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Definition
| Palatine tonsil and part of the tonsillar fossa |
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Term
| What is formed by the third pharyngeal pouch? |
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Definition
| Inferior parathyroid gland by dorsal portion and thymus by ventral portion |
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Term
| What is formed by the fourth pharyngeal pouch? |
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Definition
| Superior parathyroid gland by dorsal portion and the ultimobranchial body by the ventral portion which gives rise to parafollicular (C) cells |
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Term
| What structure is formed by the four pairs of pharyngeal clefts? |
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Definition
| External auditory meatus from the first cleft only |
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Term
| What temporary cavity is formed by pharyngeal clefts 2-4? |
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Definition
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Term
| What plugs the external auditory meatus from months 3-7? |
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Definition
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Term
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Definition
| The mesenchymal proliferations known as auricular hillocks from the first and second pharyngeal arches |
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Term
| What remnant of the cervical sinus is located laterally along the anterior border of the sternocleidomastoid muscle? |
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Definition
| Lateral cervical cyst or branchial cyst |
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Term
| When does development of the face begin? |
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Definition
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Term
| What structures form the face? |
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Definition
| The five facial primordia - frontonasal prominence, two maxillary prominences, and two mandibular prominences |
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Term
| What ectodermal thickening invaginates to form the nasal pit? |
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Definition
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Term
| The two medial nasal prominences merge to form what? |
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Definition
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Term
| What is formed by the intermaxillary segment? |
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Definition
| Philtrum of the upper lip, portion of the maxillary alveolar process carrying the four incisor teeth, primary plate |
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Term
| The medial nasal and maxillary prominences fuse to form what? |
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Definition
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Term
| What forms within the nasolacrimal groove between the lateral nasal and maxillary prominences? |
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Definition
| Nasolacrimal duct which connects the lacrimal sac to the inferior meatus of the nasal cavity |
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Term
| What forms the dorsum of the nose? |
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Definition
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Term
| What forms the sides of the nose? |
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Definition
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Term
| What forms the crest and tip of the nose? |
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Definition
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Term
| Where does the oronasal membrane break down? |
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Definition
| Future site of the incisive canals, forms the primitive choanae |
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Term
| What forms the lower lip? |
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Definition
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Term
| What forms the secondary palate? |
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Definition
| Lateral palatal shelves which are outgrowths from the maxillary prominences |
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Term
| What is a potential cause of deficient neural crest migration and proliferation causing facial clefts? |
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Definition
| High doses of retinoic acid (vit A) |
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Term
| A failure of the maxillary and medial nasal prominences to fuse causes what defect? |
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Definition
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Term
| When does the first pharyngeal arch form the anterior 2/3 (body) of the tongue? |
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Definition
| When the lateral lingual swellings overgrow the tuberculum impar |
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Term
| When does the third pharyngeal arch form the posterior 1/3 (root) of the tongue? |
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Definition
| When the tissues from the third pharyngeal arch overgrows 2nd pharyngeal arch tissues in the copula |
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Term
| What forms the extreme posterior part of the tongue? |
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Definition
| Epiglottic swelling of the fourth pharyngeal arch |
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Term
| What provides GSA innervation to the anterior 2/3 of the tongue? |
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Definition
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Term
| What provides SVA taste innervation for the tongue? |
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Definition
| CHorda tympani branch of CN VII along with the lingual branch of the mandibular nerve (V3) |
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Term
| What provides GVA and SVA taste sensation for the posterior 1/3 of the tongue? |
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Definition
| CN IX (glossopharyngeal n.) |
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Term
| What innervates the extreme posterior portion of the tongue? |
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Definition
| Superior laryngeal branch of vagus nerve |
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Term
| Tongue muscles develop from what structures? |
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Definition
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Term
| What innervates tongue muscles? |
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Definition
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Term
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Definition
| Insufficient tissue degeneration results in short lingual frenulum that extends tot he tip of the tongue |
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Term
| What makes the site of thyroid gland development? |
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Definition
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Term
| What connects the thyroid primordium to the foramen cecum as it migrates to its final position? |
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Definition
| Thyroglossal duct, may cause a thyroglossal cyst or aberrant thyroid tissue |
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Term
| The skull develops from what sources? |
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Definition
| Paraxial mesoderm and neural crest cells |
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Term
| Viscerocranium is considered what part of the skull? |
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Definition
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Term
| The neurocranium is considered what part of the skull? |
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Definition
| Enclosure which supports and protects he brain |
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Term
| What are the different portions of the neurocranium? |
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Definition
| Flat bones forming the sides and the roof are the cranial vault, floor of the neurocranium is the cranial base |
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Term
| What is another name for the skullcap? |
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Definition
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Term
| How is bone formed in the cranial base? |
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Definition
| Endochondral ossification (chondrocranium) |
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Term
| How is bone formed in the cranial vault? |
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Definition
| Intramembranous ossification (desmocranium) |
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Term
| What is the landmark that separates the chondrocranium from neural crest cell and paraxial mesoderm origin? |
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Definition
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Term
| Growth of the cranial base occurs at what landmarks? |
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Definition
| Synchondroses (cartilaginous joints) and sutures |
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Term
| Growth of the cranial vault occurs at what landmarks? |
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Definition
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Term
| True or false, the neonatal brain more than doubles in volume during the first two years. |
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Definition
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Term
| Premature fusion of sutures is known as what? |
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Definition
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Term
| What are the consequences of craniosynostosis? |
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Definition
| Restricted growth causes compensatory overgrowth at the remaining open sutures |
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Term
| The most common form of craniosynostosis due to early fusion of the sagittal suture causing a narrow skull is known as what? |
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Definition
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Term
| What causes trigonocephaly? |
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Definition
| Wedge shaped deformity of the forehead due to premature fusion of the metopic suture |
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Term
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Definition
| "Tower skull" results from bilateral coronal suture fusion |
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Term
| What causes plagiocephaly? |
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Definition
| Neurocranial and facial asymmetry due to unilateral premature fusion of the coronal and/or lamboidal sutures |
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Term
| What are some effects of midfacial hypoplasia? |
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Definition
| Abnormally small nasal and nasopharyngeal air spaces, results in difficulty breathing, difficulty eating due to malocclusion, possible impaired hearing |
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Term
| What causes exopthalmos/proptosis? |
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Definition
| Protrusion of the eyeball due to decrease in volume of the orbit - obitostenosis |
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|
Term
| What gene defects may cause craniosynostosis? |
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Definition
| Mutations in genes for fibroblast growth factor receptors (FGFR2 & FGFR1) |
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