brachial/pharyngeal arches Flashcards
what does the ectoderm form?
neural tube and skin
what does the mesoderm form?
everything else
what does the endoderm form? what arch does not contain endoderm?
gut- 1st arch
what do NCC form?
migrate from neural tube to mesoderm to form H and N structures
what are NCC cells also known as?
ecto-mesenchymal cells
what is the first arch called?
mandibular arch
what arteries are located within the first arch?
maxillary
what nerve controls the first arch ? and what artery?
trigeminal nerve- CNV
hyoid artery
what cartilage is found in the 1st arch?
meckels
what bones are formed from the first arch?
incus and malleus
what structure is formed by the 1st arch?
body of tongue
what muscles are formed by the first arch ?
-muscles of mastication: temporals, masseter and pterygoing
- anterior belly of digastric
-mylohyoid
-tensor pallentini
-tensor tympani
what syndrome occurs if NCC cells fail to migrate to the first arch?
Treacher collins syndrome
what does Treacher collins syndrome cause?
facial bone aplasia- mandible and zygomatic bone
what are the symptoms of teachers collins syndrome?
ear deformaties
dental anomalies
clefts
what is the second arch called
hyoid arch
what cartilage is found in the second arch?
reicharts
what does reicharts cartilage form?
-stapes
-lesser horn of hyoid
-superior hyoid body
-styloid process
what nerve controls the second arch?
CNVII - facial nerve
what muscles are formed by the second arch?
muscles of facial expression and posterior belly of digastric muscle
what other structures are formed by 2nd arch?
tonsils
thyroid gland
what nerve controls the 3rd arch?
glossopharyngeal nerve- CNXI
what does the 3rd arch form?
greater horn of hyoid
inferior hyoid body
root of the tongue
stylopharyngeous muscle
what artery is formed by 3rd arch?
internal carotid artery
what nerve controls the 4th arch?
vagus nerve CNX
what artery is within the 4th arch?
subclavian artery and aorta
what cartilage is found within the 4th arch?
thyroid cartilage
what else is found in the 4th arch?
-pharynx
-epiglottis
-pharangeal constrictor
-soft palate
what happens to the 5th arch?
it disappears fairly quickly
what does first punch form?
middle ear
euchastrian tube
tympanic membrane
ventral part obliterated by tongue
what does second pouch form?
tonsillar fossa
ventral part obliterated by tongue
what does 3rd pouch form?
inferior parathyroid gland
thymus
what does 4th pouch form?
superior parathyroid gland
what happens to the 2nd to 6th cleft/grooves?
they disappear due to proliferating 2nd hyoid arch
what happens if the grooves do not disappear and the 2nd hyoid arch does not proliferate?
brachial fistula/cyst
“gill-like structure”
what is the only cleft to remain?
the first- forming the EAM
what do the other proliferated clefts become?
cervical sinus
what does the 4th arch form?
pharynx and epiglottis
what muscles does the 4th arch form?
pharyngeal constrictor and soft palate
