Pharyngeal (Branchial) Arches, Pouches and Cysts Flashcards
branchial refers to
gills
pharyngeal arches form what week
4th
neural crest cells form most of what
skeletal and connective tissues of head and neck
how are pharyngeal arches numbered
cranial to caudal
how many pharyngeal arches are there
6 pairs i.e.
4 well defined pairs which are visible externally and the 5th and 6th pairs are rudimental
the pharyngeal arches are separated by what
endodermally lined pouches and ectodermally lined clefts (grooves)
each arch consists of
NAC i.e.
nerve
artery
cartilage
what prominences come from the 1st pharyngeal arch
maxilla and mandible bones
zygomatic bone
what cartilage comes from the 1st pharyngeal arch
Meckel’s cartilage
malleus and incus
anterior ligament of malleus
sphenomandibular ligament
what muscles come from the 1st pharyngeal arch
temporalis
masseter
pterygoids
mylohyoid
anterior belly of digastric
tensor veli palatini
tensor tympani
what nerve comes from the 1st pharyngeal arch
trigeminal nerve (CN V)
what do you get from the 1st pharyngeal pouch
eustachian tube
tympanic membrane
temporal bone
(tubotympanic recess)
1st pharyngeal groove develops into
external acoustic meatus
what happens to the remaining pharyngeal grooves
they disappear and form the cervical sinus
what does the 2nd pharyngeal arch overgrow
pharyngeal clefts
incomplete obliteration of the branchial clefts causes what
formation of an abnormal lateral cervical cyst or fistula
what cartilage do you get from the 2nd pharyngeal arch
Reichert’s cartilage i.e.
stapes
upper body and lower cornu of hyoid bone
the styloid process of the temporal bone
stylohyoid ligament
what muscles do you get from the 2nd pharyngeal arch
platysma
muscles of facial expression
stylohyoid
stapedius
posterior belly of digastric
what nerve do you get from the 2nd pharyngeal arch
facial nerve (CN VII)
what artery do you get from the 2nd pharyngeal arch
stapedial artery
what do you get from the 2nd pharyngeal pouch
lymphatic nodules called palatine tonsils
what does the cartilage from the 3rd pharyngeal arch form
lower body of the hyoid and greater cornu of the hyoid bone
what muscles do you get from the 3rd pharyngeal arch
stylopharyngeus
superior and middle pharyngeal constrictors
what nerve do you get from the 3rd branchial arch
glossopharyngeal nerve (CN IX)
what artery do you get from the 3rd branchial arch
common carotid
proximal portions of the internal and external carotid
what do you get from the 3rd branchial pouch
inferior parathyroids
thymus gland
what do the 4th and 6th branchial arch cartilages do
fuse to form laryngeal cartilages
what muscles do you get from the 4th branchial arch
cricothyroid
inferior pharyngeal constrictors
all muscles of the palate except tensor veli palatini
what nerve do you get from the 4th branchial arch
superior laryngeal branch of the vagus nerve
what artery do you get from the 4th branchial arch
right subclavian
aortic arch
what do you get from the 4th branchial pouch
superior parathyroid glands
parafollicular thyroid cells (ultimobranchial body)
5th branchial arch if present is
rudimentary
what muscles come from the 6th branchial arch
remaining intrinsic laryngeal musculature
what nerve comes from the 6th branchial arch
recurrent laryngeal nerve branch of vagus nerve
what artery comes from the 6th branchial arch
pulmonary artery
ductus arteriosus
what innervates the 1st branchial arch
trigeminal nerve (CN V)
what innervates the 2nd branchial arch
facial nerve (CN VII)
what innervates the 3rd branchial arch
glossopharyngeal nerve (CN IX)
what innervates the 4th and 6th branchial arches
vagus nerve (CN X)
what nerves innervate muscles derived from preotic somites
oculomotor (CN III)
trochlear (CN IV)
abducents (CN VI)
what nerve innervates muscles derived from occipital somites
hypoglossal nerve (CN XII)
trigeminal nerve innervates what
8 muscles derived from the 1st arch
facial nerve innervates what muscles
muscles of the facial expression and the rest of the muscles from the 2nd arch
what muscle does the glossopharyngeal nerve innervate
stylopharyngeus
what muscles does the vagus nerve innervate
most of the muscles of the palate
most of the muscles of the pharynx
most of the muscles of the larynx
what muscle does the hypoglossal nerve innervate
muscles of the tongue
where do branchial cysts develop
along anterior border of sternocleidomastoid
most branchial cysts are found where
inferior to angle of mandible
when do branchial cysts often present
in adulthood
what are branchial cysts
remnants of cervical sinus and / 2nd branchial groove
what are branchial vestiges and where are they located
they are cartilaginous / bony remnants
anterior to inferior third of sternocleidomastoid
what does the first arch syndrome result in
various congenital anomalies of eyes, ear, mandible and palate
what causes 1st arch syndrome
when migration of neural crest cells into the 1st branchial arch are implicated
what are the 2 manifestations of first arch syndrome
Treacher Collins syndrome- where there is underdevelopment of zygomatic bones of face, defects of lower eyelids and external ear deformities
Pierre Robin syndrome- where there is hypoplasia of the mandible, cleft palate and eye and ear defects
how does the thyroid gland develop
from endoderm of the floor of primitive pharynx between 1st and 2nd arches
it then descends as a bi-lobed diverticulum from the foramen cecum around the 4th to rest in the neck region by 7-8 week
Where do all the muscles of the larynx come from
6th pharyngeal arch except the cricothyroid
Where are the extrinsic (-glossus) and intrinsic muscles of the tongue derived from
Occipital somites except the palatoglossus (which is from 4th arch)
