Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Growth and Development > Head and Neck Development > Flashcards

Head and Neck Development Flashcards

1
Q

what do genes (DNA) encode

A

RNA and proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what does RNA and protein define

A

the identity of each cell- its appearance and how it behaves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what does gene mutation and differences in non genetic instructions determine

A

phenotype

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is the difference between epithelia and mesenchyme

A
  • epithelial cells are tightly bound to each other in sheets and are not motile
  • mesenchymal cells are surrounded by ECM and are very motile
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what are the embryonic germ layer

A
  • ectoderm
  • mesoderm
  • endoderm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what are the axes that define the craniofacial complex

A
  • left- right
  • dorsal- ventral
  • anterior- posterior
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

clinical treatments always consider:

A
  • form
  • symmetry
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

describe the embryo during the first three weeks

A
  • zygote -> 2 cell -> 4 cell -> 8 cell -> morula -> blastocyst -> late hatched blastocyst -> implantation -> carnegie stage 5 -> carnegie stage 7-9
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what axis is apparent in the first three weeks

A

dorsal ventral axxis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

is the D-V axis established as a consequence of cavitation and formation of the inner cell mass or is it determined earlier

A

determined earlier

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is visible in the blastocyst stage

A

inner cell mass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

when are the A-P and L-R axes determined

A

at the start of week 3 with the appearance of the primitive streak

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

where do epiblastic cells converge

A

at the midline and ingress

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what marks the posterior end

A

epiblastic cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what does the appearance of the primitive streak define

A

the A-P and L-R axes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

the primitive streak progressively elongates along the midline through the process of _____

A

convergent extension

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what do cells of the epiblast layer migrate through and form

A

migrate through primitive streak to form mesoderm and embryonic gut endoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what happens in gastrulation

A

-epithelial to mesenchyme transformation to form mesoderm
- movement of epiblast (ectoderm) to form embryonic endoderm - both epithelia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

describe the disproportionate growth of the germ layers

A

greater proliferation of epiblast (ectoderm) because it also generates all mesoderm and embryonic endoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

describe the node

A

anterior most end (ventral side) of primitive streak is unique in both appearance and function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what animals have the node

A

all vertebrates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what is the node essential for

A
  • patterning and induction of embryonic cells ( mesoderm and embryonic endoderm)
  • establishment of left right symmetry
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

factors secreted by cells of the node that induce anteriorly migrating mesoderm to form:

A
  • the prechordal plate
  • the notochord
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what is the prechordal plate and where is it located

A
  • provides the signals for induction of head structures
  • most anterior region of mesoderm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what is the notochord and where is it located

A
  • provides the signals for induction of the neural plate
  • transient epithelial like rod structure along the midline
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

how does the node induce the body axis

A
  • specifies the fate of the mesoderm as it is formed
  • creation of asymmetry in symmetrical embryo
  • first establishes molecular asymmetry
    -conversion into asymmetric organogenesis
27
Q

how is molecular asymmetry established

A
  • asymmetric expression of morphogenetic factors such as SHH, BMP4 and FGF8 around node
28
Q

what do morphogenetic factors around the node do

A

initiate cascade of gene expression to promote asymmetric specialisation/ commitment of mesoderm

29
Q

nodal cells each have one _____

A

motile cilium

30
Q

what is a cilium

A

a membrane covered extension from the cell that has a microtubule cytoskeleton core which helps define the properties of the cilium

31
Q

what are the possible properties of the cilium

A

mechanosensory or rotational

32
Q

how long does the rotational beat in nodal cilia last

A

for a few hours

33
Q

what does the rotational beat in nodal cilia do

A

generates leftward flow, resulting in asymmetric distribution of morphogens/ growth factors

34
Q

describe the prevalance of organ asymmetry

A

reproducible morphological and functional asymmetries in nearly all internal organs
- present in all vertebrates

35
Q

what is normal organ asymmetry also called

A

situs solitus

36
Q

what is the condition of inverted L-R organs called

A

situs inversus

37
Q

what do the nodal cilia control

A

organ asymmetry

38
Q

what is neural tube formation called

A

neurulation

39
Q

what is neurulation a precursor to

A

brain and spinal cord

40
Q

how is the neural plate formed

A

factors from the mesoderm induce thickening of overlying ectoderm which turns into the neural plate

41
Q

what do signals from notochord do

A

induce a hinge point (floor plate) to help drive folding

42
Q

describe anterior (head) specification

A

the morphological difference of the anterior most region of the neural tube reflects unique cellular identities and thus different inductive cues

43
Q

advanced maturity of anterior end =??

A

expanded neural plate -> future brain

44
Q

how does the neural tube close

A

proceeds anteriorly and posteriorly from the mid region

45
Q

by the end of week 3 the head and neck region comprises about _______ of the embryo

A

half

46
Q

what are the possible defects in neural tube closure

A

spina bifida (common, viable)

47
Q

what is head formation called

A

cephalization

48
Q

what serves at the hinge point during cephalization

A

the oropharyngeal membrane

49
Q

when does embryonic folding occur

A

-while cephalization occurs
- while pharyngeal arches form

50
Q

what structures become specialized during embryonic folding

A

foregut and hindgut

51
Q

what are neural crest cells

A

a unique population of pluripotent stem like cells originating at the crest of the enclosing neural tube

52
Q

how do neural crest cells migrate

A

ventro laterally to populate the ventral side of the embryo

53
Q

what process are neural crest cells generated by

A

epithelial mesenchymal transformation which is analagous to that generating the third germ layer (mesoderm)

54
Q

what is happening during EMT

A

cells transform from epithelial type to mesenchymal phenotype

55
Q

what does cranial neural crest cells drive

A

outgrowth of the primitive tissue masses that will form much of the head and neck
- pharyngeal arches

56
Q

what are cranial neural crest cells a major contributor to

A

craniofacial structure and specifcially to mineralized tissues of the oral region

57
Q

when is the fate of CNCC determiend

A

prior to departure from neural tube

58
Q

what are the multiple visible constrictions in the neural tube

A

rhombomeres 1-8, the diencephalon and anterior mesencephalon

59
Q

what do the visible constrictions in the neural tube define

A

distinct populations of the CNCC and their route of migration into early facial tissue

60
Q

what are the CNCC derivatives

A

mesectodermal cells: skeleton, connective tissue, muscle

61
Q

early molecule patterning during gastrulation enables _______

A

later coordinated tissue morphogenesis

62
Q

embryogenesis is a _____process. Not _____

A

generative; descriptive

63
Q

what can malformation and normal phenotypic variation result from

A

-single changes in gene sequence
- combinations of normal gene variants
- changes in the environment to which cells respond

64
Q

what is also called the second wave of development

A

CNCC migration

Growth and Development (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions