development of head and neck Flashcards
what membrane becomes the mouth?
oropharyngeal membrane
review: whats philtrum?
the dimple between your upper lip and septum of nose; its made of the frontonasal process
what four things are contained in a pharyngeal arch?
arch cartilage, arch cranial nerve, arch artery, condensation of mesenchymal tissue that will make the muscles
what arch does malleus and incus come from
trigeminal innervates the little muscle that tenses the tympanic membrane, so this is first arch
what arch does stapes come from
stapedius attaches to this. that muscle is VII, so this is second pharyngeal arch
what does PHA mean? PHP?
for me, it means pharyngeal arch and pharyngeal pouch. i’m tired of typing them
what are the divisions of the hind brain? does the midbrain and forebrain divide?
rhombomeres; this is only in the hindbrain
what are the divisions of the paraxial mesoderm?
these are somitomeres for mm. of the eye. its the name for proximal somites
name for bulges that come off the gut tube?
pharyngeal pouches. like the lung bud, thyroid bud
T/F there is a blood vessel for each arch
TRUUUUEEE!!!
what should you appreciate?
a lot of things up here come from neural crest (neural ectoderm that turns into mesoderm stuff) its really complicated, so don’t learn this stuff but know it exists
why does recurrent laryngeal nerve (5th PHA) wrap around the subclavian(4th PHA)?
the 5th aortic arch disappeared
which part of the jaw fuses first?
the MANdible.
what are the two parts of the skull that develop?
the neurocranium(skull part) and the viscerocranium (face part)
everything is cartilaginous for neurocranium except for?
parietal, frontal, and a little bit of the occipital
premature fusion of the coronal suture called? saggital?
brachocephaly; scaphencephaly
t/f muscles of the tongue come from PHAs
false. they come from myotome
what are some weird things that neural crest cells form
melanocytes, all the ganglions, schwaan cells, meckel’s cartilage (pha 1), dentine of teeth
placode is
a dense condensation of ectodermal tissue that gives rise to different strxs of the head and neck
pha 3 is what cn
IX
pha 4,6 is what cn
X
which cns are actually from somitomeres/somites
III, IV, VI, XII
PHAs of hyoid
second (upper half), third (lower half)
fourth PHA
thyroid cartilage
first arch syndrome
low set ears, malformation of malleus and/or incus, small lower jaw, auricle of ear is misshapen
**subforms of this are treacher collins and goldenhar syndrome
agnathia
no formation of the lower jaw
what chart do you need to know
the chart with arch, nerve, muscles, skeletal strxs, ligaments for PHAs
thyroid begins at this thing
foramen cecum
prominences of the first PHA
maxillary, mandibular
two things that make the pituitary gland
infundibulum of BRAIN (posterior lobe) and Rathke’s pouch (anterior lobe). these are actually from the stomodeum (roof of mouth)
where does tympanic membrane develop
between first pouch and first groove; this is why the tympanic membrane has three parts :ecto, meso, endoderm
eustacian tube opens up into pharynx because
it came from the first PHP which came from the pharynx
tonsillar fossa is from
the second PHP
what is the cervical sinus
the outside groove between the 2nd to 4th PHAs. this can remain open and you get a weird BB condition =>branchial cyst or fistula on LATERAL SIDE OF NECK
ultimobranchial body
fourth PHP. parathyroid from this
cyst in the midline of the neck
thyroglossal duct cyst. THIS is in the midline. the other (branchial) is LATERAL
tongue is INITIALLY derived from what PHAs
1,2,3,4
the final tongue product is made from what PHAs
1,3,4. the second one gets overgrown BUT there are still some taste buds (SVA) from VII on anterior 2/3 of the tongue. posterior 1/3 has GVA, SVA from IX
the three processes that make the face?
frontonasal (containing the nasal placode), maxillary, mandibular for face . the palate has a palatine process
the incisors (front four teeth) from?
premaxillary part of maxilla
the lateral part of the palate from? joining called?
palatine process; palatal raphe
retina, pigment comes from what structure?
optic cup. its brain (diencephalon). if the two layers of the cup split, then you get retinal detachment
sclera, choroid is from what germ layer
mesoderm
lens is from what germ layer
ectoderm
nasoplacode gives rise to the nose like ___ gives rise to the otic vessicle
otic placode. it eventually forms the cochlea
there are lots of??
flashcards. sorry, but you’re almost done!!
mastoid aircells from what?
first groove
what PHA is the external ear?
first
microtia?
rudimentary auricle; usuallly part of first arch syndrome
