Pharyngeal arches Flashcards Preview

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Flashcards in Pharyngeal arches Deck (67):
1

cysts

sealed cavity filled with air, pus, fluid

2

sinus

cavity within a tissue, can open externally

3

fistula

abnormal connection between 2 structures

4

migration

cells move (or don't) during development

5

Proliferation

growth in cell number thru cell division

6

Genetics

mutations change patterns in migration, proliferation, etc..

7

how many pharyngeal arches are there?

5

8

when do pharyngeal arches emerge?

at neural tube closure
about 4 weeks of development

9

what is unique about the first arch

shows two prominences
-maxillary prominence
-mandibular promnence

10

what are the components found in each arch?

nerve, artery, cartilage, and muscular component

11

aortic arches

arise from mesoderm and bridge between the truncus arteriosus and the dorsal aorta

12

aortic arch 1

maxillary and external carotid

13

aortic arch 2

stapedial

14

aortic arch 3

common and internal carotid

15

aortic arch 4

aortic and subclavian

16

aortic arch 6

pulmonary

17

cartilage arch 1

meckel's cartilage, maxilla, mandible, malleus, incus

18

cartilage arch 2

stapes, styloid process, lesser horn and upper portion of body of hyoid bone

19

cartilage arch 3

greater horn and lower portion of body of hyoid bone

20

cartilage arch 4-6

laryngeal cartilages

21

muscles arch 1

muscles of mastication
eg: temporalis, masseter, medial and lateral pterygoids

22

muscles arch 2

all muscles of facial expression

23

muscles arch 3

stylopharyngeus

24

muscles arch 4

constrictors of pharynx

25

muscles arch 6

intrinsic muscles of larynx

26

nerves of arch 1

trigeminal

27

nerves of arch 2

facial nerve

28

nerves of arch 3

glossopharyngeal (IX)

29

nerves of arch 4

vagus superior laryngeal

30

nerves of arch 6

recurrent laryngeal

31

mandibular process of arch 1 forms:

lower lip, lower face, lower cheek regions, chin, mandible, body of the tongue

32

maxillary process of arch 1 forms:

midface, upper cheek regions, upper lip sides, secondary palate, maxilla, and zygomatic bone

33

treacher collins syndrome mutation

Treachle gene mutation
1st arch syndrome

34

Pierre Robin sequence

hypoplasia of mandible, misplacement of tongue, cleft palate, defects of eye and ear, airway obstruction
*cause is unknown

35

How many pharyngeal grooves are there?

4

36

pharyngeal grooves/clefts are made of what origin?

ectoderm

37

which cleft is the only cleft not obliterated in development?

the 1st one

38

what does the 1st cleft give rise to?

the external auditory meatus

39

Preauricular sinus and cysts

often unilateral 1st or 2nd arch defect

40

Branchial sinuses, cysts, and fistulas
Lateral cervical

uncommon, open to external(to neck), failure of second groove or cervical sinus to obliterate
*if it is continuous with skin of neck it is a fistula

41

Branchial sinuses, cysts, and fistulas
Internal branchial

rare, persistent second pouch, open into intratonsillar cleft (into pharynx)
2nd pouch defect

42

how many pharyngeal pouches do you have?

4 or 5 pairs

43

pouches are of what origin?

endodermal origin

44

1st pharyngeal pouch gives to what structure?

distal portion- forms middle ear and makes the inner portion of tympanic membrane
proximal: forms eustachian tube

45

second pharyngeal pouch gives to what structure?

the lining of the crypts in the palatine tonsils and tonsillar fossa

46

third pharyngeal pouch gives rise to what?

inferior parathyroid gland(dorsal wing) and the thymus(ventral wing)

47

Fourth pharyngeal pouch gives rise to what?

superior parathyroid gland(dorsal) and the ultimobranchial body aka C cells of thyroid (ventral wing)

48

migration defects:
cervical thymus

cord of thymus persists in neck on path of descent

49

migration defects:
accessory thymus

piece of thymus remaining in path of descent

50

DiGeorge syndrome

failure of 3rd and 4th pouches to differentiate into thymus, parathyroid
-neural crest defects

51

DiGeorge syndrome CATCH 22

C: cardiac abnormality (tetralogy of Fallot)
A: abnormal faces
T: thymic aplasia
C: cleft palate
H: hypocalcemia/hypoparathyroidism

52

tetralogy of Fallot

overriding aorta
pulmonic stenosis
ventricular septal defect
right ventricular hypertrophy

53

Hox genes regulate what?

anterior to posterior identity
up and down rostral to caudal

54

T/F neural crest cells, with different anterior to posterior identities as determined by Hox expression, migrate form the Rhombomeres into the pharyngeal arches

true

55

Loss of Hox expression causes arch 2 to do what?

lose it anterior to posterior identity and gives a duplicate arch 1 structure
-so no lesser horn or upper body of hyoid, but will have two malleus, incus, and tympanic ring

56

what does the Dlx code

proximal - distal or ventral -dorsal of the arches

57

development of the tongue (floor of the arches)

arch 1 forms anterior 2/3 epithelium
arch 2 is covered up as arch 3 grows
arch 3 forms most of posterior 1/3 epithelium
arch 4 forms the bit of tongue at very back of throat

58

arch 1 in tongue formation

median tongue bud
distal tongue buds
-these become anterior 2/3 of tongue

59

arch 2 in tongue formation

forms middle swelling called copula

60

arches 3 and 4 in tongue formation

-hypopharyngeal eminence over grows copula(arch 2) and gives rise to posterior 1/3
*epiglottis arises posterior to hypopharyngeal eminence

61

where do tongue muscles come from?

occipital somites

62

what is the dividing line between oral tongue and pharyngeal tongue

terminal sulcus groove

63

what is the foramen cecum

at the midline and is the site of thyroid primordium

64

thyroid gland developement

forms from an endodermal diverticulum(pouch) just posterior to the floor of the 1st arch
**this not a pharyngeal pouch!!
not bilateral
-diverticulum elongates into the thyroglossal duct.

65

development of the pituitary gland

forms from the upward invagination of the oral ectoderm in the stomodeum (Rathke's pouch)
-separates from oral epithelium, moves into contact with diencephalon.

66

neurohypophysis(posterior pituitary)

develops from the developing brain (neural ectoderm)

67

adenohypophysis (anterior pituitary)

develops from the stomodeum roof (oral ectoderm).