embryology Flashcards
where do the pharyngeal (brachial) arches develop?
vertebrae
which week of development do they form?
week 4 and 5
what are the components of pharyngeal apparatus?
core pharyngeal arch (mesenchymal)
external pharyngeal (ectoderm)
internal pharyngeal (endoderm)
clefs (external) and pouches (internal) separate arches
where are the core of mesenchymal derived from and what do they give rise to?
paraxial and lateral plate mesoderm
musculature
what cells give rise to connective tissue and smooth muscle?
neural crest cells
what is the maxillary process of the 1st arch?
cranial portion
maxillary process
zygomatic bone
what is the mandibular process of 1st arch?
caudal portion
forms meckels cartilage
incus and malleus (ear ossicles)
mandible
squamous portion of temporal bone
what nerve is involved in the 1st arch?
trigeminal nerve - maxillary and mandibular divisions
what cranial nerve supplies all the musculature of 1st arch?
CN V3
what musculature is involved in 1st arch supplied by CN V3?
muscles of mastication
tensor veli palatini
tensor tympani
mylohyoid
anterior belly of diagastric
what type of cartilage is formed from 2nd arch?
reichter’s cartilage
what structures are formed from 2nd arch?
stapes
styloid process of temporal bone
stylohyoid ligament
lesser horn of hyoid
upper part of hyoid body
facial nerve
what cranial nerve supplies the musculature of 2nd arch?
CN VII
what musculature is involved in 2nd arch which is supplied by CN VII?
muscles of facial expression
posterior belly of digastric
stylohyoid
stapedius
auricular muscles
what is formed from 3rd arch?
greater horn of hyoid
lower part of hyoid
glossopharyngeal nerve
what cranial nerve supplies the musculature of 3rd arch?
CN IX
what musculature is involved in 3rd arch supplied by CN IX?
stylopharyngeus
what is involved in arches 4-6?
laryngeal cartilage
vagus nerve = 4th -> sup branch, 6th -> inf branch
what cranial nerve supplies the musculature in arches 4-6?
CN X
what musculature is involved in arch 4?
levator veli palatini
salpingopharyngeus
palatglossus
palatopharyngeus
3 pharyngeal constrictors
cricothyroid
what musculature is involved in arch 6?
intrinsic muscles of the larynx
what does the 1st cleft give rise to?
external acoustic meatus
the 2nd-4th cleft looses contact with the outside, what does it form?
cervical sinus
what causes cervical (branchial) cysts and fistulas?
failure of obliteration the 2nd-4th cleft
usually along anterior border of sternocleidomastoid
not seen at birth enlarges during childhood
what is involved in the 1st pharyngeal pouch?
tympanic membrane
middle ear
eustachian tube
what is involve din the 2nd pharyngeal pouch?
palatine tonsil
what is involved in the 3rd pharyngeal pouch?
inferior parathyroid gland
thymus
