development of pharyngeal arches (S2) Flashcards
what are the 3 components of the pharyngeal complex
arch, cleft, pouches
what is the mesenchyme that creates the facial skeleton come from
neural crest
what do the muscles of the face originate from
mesoderm
what do the posterior portions of the neurocranium and basicranium come from
mesoderm
what are the anterior portions of the sphenoid and frontal bones derived from
neural crest
what does the first pharyngeal arch form
maxillary and mandibular prominence
what nerve supplies tissues derived from the first arch
trigeminal ganglion
what type of muscles arise from arch one
muscles of mastication
what type of muscles arise from arch 2
facial expression
what muscle arises from arch 3
stylopharyngeus
what structures are formed from the frontonasal prominence
forehead, bridge of nose and lateral nasal prominences
what structures are formed from the maxillary prominence
cheeks, lateral portion of upper lip
what structures are formed from the medial nasal
philtrum of upper lip, crest and tip of nose
what structures are formed from the lateral nasal
alae of nose
what structure is formed from the mandibular prominence
lower lip
what signal makes sure that the tongue drops down and out of the way and also that it is mobile
Tbx22
where are BMPs located and expressed
expressed early; superficial location-palatal shelves
what mutation can lead to ankyloglossia
mutation of TBX22
what is median cleft lip due to
incomplete merging of the 2 medial nasal prominences
what does a complete cleft palate involve
cleft of the palate and alveolus
what type of communication occurs as a result of a complete cleft palate
open communication between oral and nasal cavities
what occurs when there is a bilateral cleft palate
the pre maxilla is unattached, allowing it to grow forwards
define macrostomia
hypoplasia or incomplete fusion of maxillary and mandibular prominences. typically results in abnormally large mouth
what are some class arch 1 abnormalities
treacher-collins syndrome and pierre robin syndrome
describe the phenotype associated with treacher-collins syndrome
downward-slanting eyes, small mandible and malformed/absent ears, autosomal dominant (chromosome 5)
describe characteristics of pierre robin sequence
micro/retrognathia, glossoptosis, and airway obstruction. more specifically is problem with mandible
what does the posterior part of arch 2 differentiate into
stapes and styloid process of temporal bone
what does the anterior portion of arch 2 differentiate into
lesser horns (cornu) and the superior portion of hyoid bone)
where does the stylohyoid ligament form
in between the anterior and posterior portions of the second arch
what are the skeletal elements of the 3rd arch
greater horn (cornu) and inferior portion of hyoid bone
where does the epiglottis come from
laryngeotracheal diverticulum
what does aortic arch 1 contribute to
maxillary arteries
what does aortic arch 2 contribute to
produce stapedial and hyoid arteries
what does aortic arch 3 contribute to
common carotid arteries and proximal portion of internal carotid arteries
what is derived from the 1st pharyngeal cleft
external auditory meatus
what is derived from the 1st pharyngeal pouch
middle ear, auditory tube
what is derived from the 2nd pharyngeal pouch
supra-tonsillar fossa, palatine tonsils
what is derived from the 3rd pharyngeal pouch
thymus, parathyroid gland
what is derived from the 4th pharyngeal pouch
ultimobranch. body
what can remnants of the pharyngeal clefts 2-4 appear as
cervical cysts or fistulas along anterior border of sternocleidomastoid muscle
what is located between the first pouch and cleft
tympanic membrane
what is digeorge syndrome characterized by
hypoparathyroidism which results in hypocalcemia, hypo plastic or absent thymus, conotruncal heart defects, cleft lip and/or palate
what does the anterior part of the tongue arise from
1st arch that is formed from 3 masses
what 3 masses form the anterior part of the tongue
2 lateral lingual swellings and the tuberculum impar
what does the base of the tongue develop from
3rd arch
what is the site called where the base and the body of the tongue come together
sulcus terminalis
what provides sensory innervation to the anterior 2/3 of the tongue
lingual nerve, branch of trigeminal nerve, CN V
what innervates the taste buds of the anterior 2/3 of the tongue
facial nerve, CN VII (chorda tympani)
what does the posterior 1/3 of the tongue arise from
hypopharyngeal eminence
what provides sensory innervation to the posterior 1/3 of the tongue
glossopharyngeal nerve, CN IX
what does thyroid gland arise from
midline thyroid diverticulum
what is the site of the opening of the thyroglossal duct
foramen cecum
where is the thyroid diverticulum positioned
between the anterior 2/3 and posterior 1/3 of the developing tongue
