Embryology Flashcards
where would you find pharyngeal arches
face and neck
when do pharyngeal arches develop
week 4 and 5
what 4 things do pharyngeal arches contain
core mesenchyme derived from paraxial and lateral plate mesoderm
neural crest cells
cranial nerve component
artery
How many arches are there
5 (1,2,3,4,6)
What does the mesenchyme control
musculature of the face and neck
what controls the skeletal components of the face
neural crest cells
where are clefts found
in the ectoderm in between the arches
what separates the arches internally in endoderm side
Pouches
what nerve arises from the 1st pharyngeal cleft
Trigeminal nerve- mandibular and maxillary divisions
which arch does the facial nerve arise from
2nd arch
What nerve arises from the 3rd pharyngeal arch
glossopharyngeal nerve
Where does the superior laryngeal branch form?
arch 4
what arises from 6th arch
recurrent laryngeal nerve
in the first arch, what 3 things make up the skeletal component in maxillary process
maxilla, part of temporal bone and zygomatic process
what is contained within mandibular process (3)
incus, malleus and mandible
what muscles arise from the first arch
mastication muscles, mylohyoid, tensor tympani and palatini
What is the nerve that innervates the face
trigeminal
what skeletal components make up the 2nd arch
stapes, styloid process of temporal bone and stylohyoid ligament
What muscles arise form the 2nd arch
facial expression muscles, stapedius, stylohyoid, auricular muscles
what nerve supplies the 2nd arch
facial nerve
what is the skeletal, muscular and nerves that arise from the 3rd arch
greater horn and lower part of body of hyoid, stylopharyngeus, glossopharyngeal nerve
what muscles would you find in arch 4 and what is their innervation
cricothyroid, levator palatini, pharyngeal constrictors- superior laryngeal nerve
what muscles arise form the 6th arch
intrinsic laryngeal muscle, by recurrent laryngeal nerve
what is found in the first pouch
middle ear, eustachian tube, tympanic membrane
what is found in the second pouch
palatine tonsil
what is found in the 3rd pouch
inferior parathyroid gland, thymus
what is found in the 4th pouch
superior parathyroid gland, ultimobranchial body
what would you find in the pharyngeal clefts
external acoustic meatus
what happens to the 2-4th cleft
forms the cervical sinus which disappears eventually
what is an otis placode
thickening of the ectoderm which forms the ear
what does otic vesicles give rise to
inner ear
what is the dilated end of the semi circular canal called
crus ampullare
what is the non dilated end of the mi circular canals called
crus nonampullare
what is crus ampullaris used for
sensory cells for balance, vestibular fibres of VIII
what portion gives rise to semicircular canals
urtricular
what does the saccular portion give rise to
cochleA
when does the cochlea grow
between 6-8 weeks
what controls hearing
organ of corti
what controls balance
semicircular canals
what does the meatal plug form in month 7
ear drum
how many proliferations surround 1st pharyngeal cleft
3 form arch 1 and 3 from arch 2
