Embrylogy Flashcards
what does the mesoderm form for maxillary prom?
nothing!
site of opening of thyroglossal duct
foramen cecum
What forms stapes?
Arch 2 NC
Thyroglossal duct cyst
cystic remnant of thyroglossal duct mass at midline of neck at level of hyoid bone. could contain ectopic thyroid tissue
what forms the intermaxillary segment
Fusion of maxiallary promience and medial nasal promiences
NC arch 3
greater hornu of hyoid body of hyoid
Tooth process after formation
Baby/deciduous teeth erupt sequentially from incisors to molars Deciduous and permanent teeth are generated during fetal development and are staggered. Growth of max and mandible is to accommodate 2nd set of tooth buds. Tooth development is crucial to jaw growth
what gives rise to the inferior parathyroid gland?
Pharyngeal pouch 3 dorsal
Facial prominences names
Frontonasal maxillary mandibular
What is the stylohyoid m. derived from?
Arch 2, mesoderm
Cleft lip
Intermaxillary failure to fuse with maxillary prominence
what forms styloid process
Arch 2 NC
What forms the zygomatic bone?
Maxillary prominence NC cells
Nasal Placodes
ectodermal thickening of Frontonasal prominence on lateral aspects and skin to give rise to nasal pits
What is the tensor tympani m. derived from?
mandibular prominence, mesoderm
what does the mesoderm form for Arch 4?
Muscles of soft palate muscles of pharynx proximal right subclavian arch of aorta
Stromodium
Opening for the oral cavity
As diverticulum elongates caudally, it remains attached to the tongue and pharynx via the ______ duct.
thyroglossal
pharyngeal membrane
where ectoderm and endoderm meet
what gives rise to the cervical sinus/
Pharyngeal celfts 2-4
What is the posterior digastric m. derived from?
Arch 2, mesoderm
Dental buds
ectodermal epithelium invaginates at week 8
what gives rise to the ultimopharyngeal body?
Pharyngeal pouch 4 ventral
what forms incus?
Mandibular prom. NC
Innervation of arch 3?
Glossopharyngeal N. Somatosensory and paste to post 1/3 of tongue
Copula
also hypobranchial eminence formed by 2nd arch formed posterior to tuberculum impar overtaken by 3rd arch swellings during weeks 5-10
Primary palate
formed from intermaxillary segment - fusion of medial nasal prominences anterior, triangular portion
What are the muscles of mastication derived from?
Mandibular prominence, mesoderm
What arch forms the maxillary and mandibular prominences?
Pharyngeal arch 1
What are the muscles of pharynx derived from?
Arch 4, mesoderm
Nasal pits
sinking inside the nasal placodes. These later dilate to form nasal sacs
What gives rise to the auditory tube?
Pharyngeal pouch 1
What gives rise to the mastoid atrium?
Pharyngeal pouch 1
Formation of teeth
Dental bud invaginate to form a cap around a dental papilla (incorporated in middle of claw) mesenchyme (neural crest cells) at week 10 Bell Stage: dental papilla elongates to form bell connection for oral epithelium degenerates formation of dentin and enamel
what does the mesoderm form for Arch 3?
Stylopharyngeus m. common carotid a proximal internal carotid a.
terminal sulcus
fusion between arch 1 and hypopharyngeal emincne
Innervation of Arch 4/6?
Vagus Somatosensory and taste of pharynx and larynx and esophagus
Foramen cecum
site of opening of thyroglossal duct indentation between post and anterior tongue
how is anterior 2/3 of tongue formed?
lateral lingual swellings of 1st pharyngeal arch lined by ectoderm (because arch1 is lined mostly by ectoderm)
Innervation of Arch 2?
Facial N. Motor: muscles Sesnory: special sensory taste to anterior 2/3 of tongue
What forms great hornu of hyoid?
Arch 3 NC
DiGeorge Syn
Paryngeal pouch 3-4 pharyngeal arch 1/2 neural crest parathyroid insufficiency - hypocalcium small mandible, cleft palate, small ears, cardiovascular defects
what gives rise to the superior parathyroid gland?
Pharyngeal pouch 4 dorsal
Innervation of Arch 1?
Trigmeminal N. Motor to muscles Sensory: somatosensation of teeth, face, ant 2/3 of tongue, palate
What does the pharyngeal pouch 2 give rise to?
palatine tonsilar bed
What does the lateral nasal prominence form?
Alae of nose and fuses with MxP to create smooth facial line Nasolacrimal duct
What are the muscles of facial expression derived from?
Arch 2, mesoderm
What makes up arch 1?
a maxillary and mandibular crest
Nasal prominences
elevated regions around the nasal pits. There are both medial and lateral nasal pits
What is the pharyngeal arch core made out of?
paraxial mesoderm and neural crest mesenchyme
What happens during week 6-10 for facial develpment
Maxillary prominences grow together and force middle nasal prominenes to fuse and form bridge of nose and intermaxillary senate.
What does the neural crest mesenchyme cells form?
bone, cartilage, Connective tissue
Pyramidal lobe
formed by the thyroglossal duct degeneration in week 12
What gives rise to the tonsilar bed?
Pharyngeal pouch 2
Steps in secondary palate formtion
Palatine shelves growth caudally to developing tongue around week 9, growth of mandible shifts tongue downward and palatine shelves fuse and swing up and fuse to primary palatine
What forms the squamous temporal bone?
Maxillary prom. NC cells
tongue buds
formed by median lingual swellings
Olfactory epithelium
Derived from diff. cranical ectoderm in nasal cavity
innervation of tongue
Ant 2/3: somatosensory Lingual from trigeminal taste: from chorda tympani of facial n. motor: hypoglossal n. Post 1/3: Somatosensory: glossopharyngeal and some vagus taste: glossopharyngeal motor: hypoglossal
Pharyngeal aparatus
at approximately 4 weeks formed by ventral migration of neural crest cells contributes to face, jaw, ear, and neck form from cranial to caudal
what forms sylohyoid lig
Arch2 NC
what forms body of hyoid?
Arch 3 NC
Cleft palate
Failure to fuse of secondary and primary palates (intermaxillary and maxillary)
Maxillary arch Neural crest cells form:
maxilla, zygomatic and squamous temporal bone
What gives rise to the tympanic cavity?
Pharyngeal pouch 1
NC arch 4/5
laryngeal cartilage (thryoid and cricoid cart)
what does the intermaxillary segment give rise to?
Philtrum (upper lip) Upper jaw with 4 incisors primary palate (triangular poriton)
What does the paraxial mesoderm form?
arch artery, skeletal muscle, drag in neuronal component
Fungiform
lingual papillae large mushroom like among filiform has taste buds made of CY that project outward
what forms the bridge of the nose?
fusion of medial nasal prominences
Treacher collins syndrome
Pharyngeal arch 1 affected hyopastic zygomatic arch, small lower jaw
Secondary palate
complete by 12 weeks fusion of palatine shelves forms hard palate and all of soft formed by outgrowths of maxillary prominence
What does the pharyngeal pouch 4 give rise to?
ventral (ultimopharyngeal body (parafollicular cells of thyroid that give rise to calcitonin) dorsal (superior parathyroid gland)
What are the muscles of laryngeal derived from?
Arch 6, mesoderm
Whats forms malleus?
Mandibular prom. NC
Peirre-Robin syn
Pharyngeal Arch 1 affected with mandibular prominence neural crest cells hypoplastic mandible Secondarly effect celft palate tongue is dorsally displaced so it influences breathing
Pharyngeal pouch
separates arches with endoderm
what is the esophagus skeletal m. dervied from?
Arch 6, mesoderm
Filiform
lingual papillae most numerous on anterior 2/3 of tongue formed by thickened epithelial tissue No taste buds - grip food
What are the anterior digastric derived from?
mandibular prominence, mesoderm
Hypopharyngeal emince
poster 1/3 of tongue. formed by arches 3-4 covered in endoderm
Foliate
lingual papillae short vertical folds on posterior side of tongue contain taste buds have 8-12 of them in front of sulcus terminalis
What gives rise to the tympanic membrane?
membrane 1
what does the mesoderm form for mandibular prom?
Muscles of mastification: masseter, temporal, anterior belly of digastric, mylohyoid, tensor tympani maxillary artery
What forms thyroid cart
Arch 4, NC
Pharyngeal cleft/groove
separates arches with ectoderm
What does the pharyngeal pouch 3 give rise to?
ventral (thymus) dorsal (inferior parathyroid gland)
what gives rise to cervical vesicle?
Arches 2-4 - degenerates with time
What is the stylopharyngeus m. derived from?
Arch 3, mesoderm
what does pharyngeal cleft 1 give rise to?
external auditory meatus
What is the mylohyoid m. derived from?
mandibular prominence, mesoderm
What are the muscles of soft palate derived from?
Arch 4, mesoderm
What forms cricoid cart
Arch 6, NC
Types of lingual papillae
filiform fungiform foliate circumvallate
What forms palatine shelves
outgrowth of max prominence by neural crest mesenchyme
What does the maxillary prominence form during fusion of intermaxillary?
Ventral: smooth upper lip Dorsal: 1 and 2 palate fusion
Nasal sacs give rise to
fusion at midline to from single nasal cavity separated by oral cavity by oronasal membrane
What gives rise to the external auditory meatus?
Cleft 1
Circumvallate
lingual papillae done structures on lateral wall taste buds have glands that flush away tonsils to free buds for new flavors
Fate of the oronasal membrane
ruptures dorsal to the primary palate and becomes continuous. This opening in the primorida choana. after birth, secondary plates close to separate nasal from oral cavity
median sulcus formation
fusion between 2 lingual swellings
Dentin
produced from NCMesenchyme that gives rise to odontoblasts gives shape of tooth
what does the mesoderm form for Arch 6?
laryngeal muscles sk muscle of esophagus ductus arteriosus
thyroglossal duct
As diverticulum elongates caudally, it remains attached to the tongue and pharynx via this duct.
What does the pharyngeal pouch 1 give rise to?
tympanic cavity, mastoid atrium, auditory tube
midline thyroid diverticulum
endoderm between pharyngeal arch 1 and 2 invaginate caudally and differentiate into follicular cells to form a thyroid gland.
Mandibular arch neural crest cells form:
Mandible, malleus, incus, anterior ligament of malleus, meckel’s cartilage
NC of Arch 2
lesser cornu of hyoid stylohyoid lig styloid process stapes
Enamel
created from outer epithelial/ectoderm differentiation into ameloblasts Ameloblasts are sloughed off when teeth erupt
Dental lamina
formed in epithelium of mandible and maxilla in mucosa lining
Oblique cleft
Failure of maxillary sinus to fuse with lateral prominences
Tuberculum impar
medal lingual swellings of arch 1 enlargement to form buccal part of tongue
Development of tongue timeline
Week 4 Skeletal muscles of tongue from paraxial mesoderm
what does the mesoderm form for Arch 2?
Muscles of facial expression posterior belly of digastric stylohyoid m.
What forms meckel’s cart?
Mandibualr prom NC
What gives rise to the thymus?
Ventral Pharyngeal pouch 3
What forms lesser cornu of hyoid
arch 2 NC
what does pharyngeal membrane 1 give rise to?
tympanic membrane