development of head and neck

Question 1

what membrane becomes the mouth?

Answer 1

oropharyngeal membrane

Question 2

review: whats philtrum?

Answer 2

the dimple between your upper lip and septum of nose; its made of the frontonasal process

Question 3

what four things are contained in a pharyngeal arch?

Answer 3

arch cartilage, arch cranial nerve, arch artery, condensation of mesenchymal tissue that will make the muscles

Question 4

what arch does malleus and incus come from

Answer 4

trigeminal innervates the little muscle that tenses the tympanic membrane, so this is first arch

Question 5

what arch does stapes come from

Answer 5

stapedius attaches to this. that muscle is VII, so this is second pharyngeal arch

Question 6

what does PHA mean? PHP?

Answer 6

for me, it means pharyngeal arch and pharyngeal pouch. i’m tired of typing them

Question 7

what are the divisions of the hind brain? does the midbrain and forebrain divide?

Answer 7

rhombomeres; this is only in the hindbrain

Question 8

what are the divisions of the paraxial mesoderm?

Answer 8

these are somitomeres for mm. of the eye. its the name for proximal somites

Question 9

name for bulges that come off the gut tube?

Answer 9

pharyngeal pouches. like the lung bud, thyroid bud

Question 10

T/F there is a blood vessel for each arch

Answer 10

TRUUUUEEE!!!

Question 11

what should you appreciate?

Answer 11

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

Question 12

why does recurrent laryngeal nerve (5th PHA) wrap around the subclavian(4th PHA)?

Answer 12

the 5th aortic arch disappeared

Question 13

which part of the jaw fuses first?

Answer 13

the MANdible.

Question 14

what are the two parts of the skull that develop?

Answer 14

the neurocranium(skull part) and the viscerocranium (face part)

Question 15

everything is cartilaginous for neurocranium except for?

Answer 15

parietal, frontal, and a little bit of the occipital

Question 16

premature fusion of the coronal suture called? saggital?

Answer 16

brachocephaly; scaphencephaly

Question 17

t/f muscles of the tongue come from PHAs

Answer 17

false. they come from myotome

Question 18

what are some weird things that neural crest cells form

Answer 18

melanocytes, all the ganglions, schwaan cells, meckel’s cartilage (pha 1), dentine of teeth

Question 19

placode is

Answer 19

a dense condensation of ectodermal tissue that gives rise to different strxs of the head and neck

Question 20

pha 3 is what cn

Answer 20

IX

Question 21

pha 4,6 is what cn

Answer 21

X

Question 22

which cns are actually from somitomeres/somites

Answer 22

III, IV, VI, XII

Question 23

PHAs of hyoid

Answer 23

second (upper half), third (lower half)

Question 24

fourth PHA

Answer 24

thyroid cartilage

Question 25

first arch syndrome

Answer 25

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

Question 26

agnathia

Answer 26

no formation of the lower jaw

Question 27

what chart do you need to know

Answer 27

the chart with arch, nerve, muscles, skeletal strxs, ligaments for PHAs

Question 28

thyroid begins at this thing

Answer 28

foramen cecum

Question 29

prominences of the first PHA

Answer 29

maxillary, mandibular

Question 30

two things that make the pituitary gland

Answer 30

infundibulum of BRAIN (posterior lobe) and Rathke’s pouch (anterior lobe). these are actually from the stomodeum (roof of mouth)

Question 31

where does tympanic membrane develop

Answer 31

between first pouch and first groove; this is why the tympanic membrane has three parts :ecto, meso, endoderm

Question 32

eustacian tube opens up into pharynx because

Answer 32

it came from the first PHP which came from the pharynx

Question 33

tonsillar fossa is from

Answer 33

the second PHP

Question 34

what is the cervical sinus

Answer 34

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

Question 35

ultimobranchial body

Answer 35

fourth PHP. parathyroid from this

Question 36

cyst in the midline of the neck

Answer 36

thyroglossal duct cyst. THIS is in the midline. the other (branchial) is LATERAL

Question 37

tongue is INITIALLY derived from what PHAs

Answer 37

1,2,3,4

Question 38

the final tongue product is made from what PHAs

Answer 38

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

Question 39

the three processes that make the face?

Answer 39

frontonasal (containing the nasal placode), maxillary, mandibular for face . the palate has a palatine process

Question 40

the incisors (front four teeth) from?

Answer 40

premaxillary part of maxilla

Question 41

the lateral part of the palate from? joining called?

Answer 41

palatine process; palatal raphe

Question 42

retina, pigment comes from what structure?

Answer 42

optic cup. its brain (diencephalon). if the two layers of the cup split, then you get retinal detachment

Question 43

sclera, choroid is from what germ layer

Answer 43

mesoderm

Question 44

lens is from what germ layer

Answer 44

ectoderm

Question 45

nasoplacode gives rise to the nose like ___ gives rise to the otic vessicle

Answer 45

otic placode. it eventually forms the cochlea

Question 46

there are lots of??

Answer 46

flashcards. sorry, but you’re almost done!!

Question 47

mastoid aircells from what?

Answer 47

first groove

Question 48

what PHA is the external ear?

Answer 48

first

Question 49

microtia?

Answer 49

rudimentary auricle; usuallly part of first arch syndrome