Development: Pharyngeal Apparatus and Larynx Flashcards
pharyngeal apparatus is also known as
branchial apparatus
most congenital anomalies result from what
failed apoptosis
this is where the arterial trunk from the heart comes from
truncus arteriosus
develop of the head and neck begin around what week of gestation
4th week
what germ layers make up pharyngeal arch
core of mesenchyme
covered externally by ectoderm
covered internally by endoderm
where is most of the mesenchyme derived from during the 4th week
neural crest cells
where do skeletal muscle and vascular endothelia come from
mesoderm of pharyngeal arch
what does each arch contain (4 things)
aortic arch
cartilaginous rod
muscle
cranial nerve
1st pharyngeal arch is also known as
T Arch
what 2 prominences does the mandibular arch give rise to
mandibular
maxillary
1st pharyngeal arch cartilage called
Meckel’s cartilage
dorsal end of 1st arch cartilage ossifies to form
malleus and incus
ventral part of 1st arch cartilage forms
primordium of mandible
1st pharyngeal arch muscles
ALL the T’s:
masTication muscles
(Temporalis, masseTer, pTerygoids)
Tensor Tympani
Tensor Veli Palatini
Mylohyoid and anterior belly of digastric
1st pharyngeal arch cranial nerve
CN V (Trigeminal)
2nd pharyngeal arch is also known as
S Arch
Hyoid Arch
2nd pharyngeal arch cartilage
Reichert’s cartilage
dorsal end of 2nd arch forms what
stapes and styloid process
2nd pharyngeal arch muscles
muscles of facial expreSSion
Stapedius
Stylohyoid and posterior belly of digastric
2nd pharyngeal arch cranial nerve
CN VII
3rd pharyngeal arch cartilage ventral part forms
superior cornu of thyroid cartilage
greater cornu of hyoid
3rd pharyngeal arch muscles
stylopharyngeus
3rd pharyngeal arch nerve
CN IX
4th and 6th pharyngeal arch cartilages fuse to form
laryngeal cartilages (NOT epiglottis)
4th pharyngeal arch muscles
cricothyroid
all muscles of soft palate (except tensor veli palatini (1st arch))
all muscles of pharynx (except stylopharngeus (3rd arch))
6th pharyngeal arch muscles
intrinsic muscles of larynx (except cricothyroid (4th arch))
nerve to 4th and 6th arches
CN X
2 branches of vagus nerve that supplies 4th arch
superior laryngeal n and pharyngeal branches (top)
branch of vagus nerve that supplies 6th arch
recurrent laryngeal n
1st pharyngeal pouch
tubotympanic recess (in the ear)
2nd pharyngeal pouch
ultimately forms into palatine tonsils
3rd pharyngeal pouch (dorsal and ventral parts)
dorsal- parathyroid glands
ventral- thymus
4th pharyngeal pouch (dorsal and ventral)
dorsal- superior [parathyroid glands]
ventral- postbranchial body (ultimobranchial body)
what pouch gives rise to C-cells that produce calcitonin
4th
anomalies are due to what
abnormal migration
failed apoptosis
1st pharyngeal groove/cleft becomes
external acoustic meatus
1st pharyngeal membrane becomes
tympanic membrane
1st endocrine gland to develop
thyroid gland
thyroid gland is initially connected to what
foramen cecum by thryoglossal duct
what week is the thryoid gland functioning
11th
most common metabolic disorder in neonates and particularly in 3rd world countries
congenital hypothyroidism (cretinism)
which cyst is midline
thryoglossal duct cyst
which cyst is lateral
branchial cyst
what do you check for when sticking tongue out
thyroglossal duct cyst (see if it moves up or down)
cyst that is anterior to sternocleidomastoid
branchial cyst
cyst that is anterior to thyroid cartilage
thyroglossal duct cyst
special sensory to anterior 2/3rds of tongue
CN VII
general sensory to anterior 2/3rds of tongue
lingual n. (CN V3)
sensory to posterior 1/3 of tongue
CN IX
hypopharyngeal eminence develops into
epiglottis
what migrates to tongue and brings what nerve with it
myotomes; CN XII
remnants of thyroglossal duct
lingual cyst
macroglossia
large tongue
microglossia
small tongue
ankyloglossia
short lingual frenulum (tongue-tie)
this syndrome happens because individual doesn’t get enough neural crest cell migration in 1st arch
Treacher Collins Syndrome (TCS)
underdeveloped zygomatic bones
downslanting palpebral fissure
defects in lower eye lids
deformed external ears
(looks like the whole face is slanted down)
Treacher Collins Syndrome (TCS)
this syndrome has insufficient mandible development and doesn’t pull tongue forward
leads to respiratory issues
Pierre Robin Syndrome
caused by microdeletion of q11.2 of chromosome 22 and 3rd and 4th pouch don’t develop
square face
chromosome 22q11.2 deletion syndrome
chromosome 22q11.2 deletion syndrome is also known as
DiGeorge syndrome