Brainscape's Knowledge GenomeTM

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


See full index

Anatomy II > Lecture 1: Limb Development > Flashcards

Lecture 1: Limb Development Flashcards

1
Q

limb field definition

A

hox genes determine in which position each of the 4 limb buds will form in vertebrates

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

what substance plays an important role in initiating limb bud outgrowth

A

retinoic acid

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

what 4 developmental tissues/cells give rise to forelimb and hindlimb

A

ectoderm
dermatome
myotome
somatic lateral plate mesoderm

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

what determines the timing of limb development

A

different hox genes expressed at different times

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

how do limb elements develop (in what direction)

A

proximal to distal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

T box genes determine

A

limb identity (pectoral vs thoracic)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what do hox genes determine (2)

A

where limb buds will form
what limb will develop at specific location

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

what forms the core of the limb field

A

mesenchyme (undifferentiated tissue)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

3 early development steps: limb field to limb bud

A

induction of limb development –> establishment of AER and ZPA signaling centers –> promotion of outgrowth and patterning in established limb bud

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

origination of limb buds (what/where)

A

ridges in ventrolateral body wall

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

2 types of limb buds

A

forebud
hindbud

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

which limb bud develops first

A

forebud

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

3 axes where limbs develop simultaneously

A

proximodistal
dorsoventral
craniocaudal

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

AER/apical ectodermal ridge: definition

A

thickened, specialized epithelium

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

what does AER induce proliferation of

A

limb bud mesenchyme through progress zone

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

progress zone: definition, function

A

area of mesenchyme just proximal to AER
encourages growth

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

proximodistal axis determined by

A

fibroblast growth factor acting at the AER

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

dorsoventral axis determined by

A

non AER dorsal ectoderm
folding initiated by Wnt7a

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

craniocaudal axis determined by

A

sonic hedgehog genes acting at zone of polarizing activity

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

feedback loop of limb development and continued AER growth

A

lateral plate mesoderm expressing fibroblast growth factors to create more growth at AER

21
Q

what happens to each limb bud once acquiring terminal length

A

terminal portion flattened to form hand and foot plates

22
Q

what divides portion of each limb bud once they’ve become hand and foot plates

A

2 constrictions

23
Q

proximal-distal development steps (3/4)

A

formation of hand and foot plates
2 constrictions
limb bud with 3 main segments = stylopod, zuegopod, autopod
mesenchyme condenses into cartilage for future long bones

24
Q

stylopod

A

arm/thigh

25
Q

zeugopod

A

forearm/leg

26
Q

autopod

A

hand/foot

27
Q

what directs pattern formation in dorsal ventral axis

A

non AER ectoderm

28
Q

what gene expression initiates limb forming interactions between ectoderm and mesoderm

A

Fgf 10

29
Q

how are final constrictions and separation of digits formed (what process)

A

apoptosis/programmed cell death

30
Q

dorsal and ventral aspects of limb follow what process

A

lateral folding of embryo

31
Q

what is dorsal-ventral axis important for

A

patterning muscles

32
Q

where does D/V (dorsal/ventral) center reside

A

dorsal ectoderm

33
Q

result of AER signaling in cranial-caudal axis

A

Shh (sonic hedgehog) expression and formation of ZPA

34
Q

what is the origin of all nerves

A

ventral primary ramus

35
Q

what nerves follow growing muscle and provide motor innervation

A

ventral and dorsal branches of ventral ramus

36
Q

what cells express retinoic acid and sonic hedgehod

A

ZPA cells

37
Q

what 2 inputs are required for ZPA and sonic hedgehog expression

A

AER
dorsal ectoderm

38
Q

homology definition

A

existence of shared ancestry between a pair of structures or genes in different species

39
Q

pentadactyl limb

A

ancestral 5 digit condition

40
Q

digit reduction is the result of what

A

species specific evolutionary history

41
Q

2 types of patterning changes of cell death

A

patterning
post patterning

42
Q

post patterning changes: starting condition, order to digit reduction

A

initial limb segments laid out in cartilage
digits I and V eliminated
digits II and IV reduced

43
Q

what 2 mammals have post patterning changes

A

horses
camels

44
Q

patterning changes: starting condition, order of digit reduction

A

never start with a pattern
digit loss and shift of central axis of foot between digits III and IV (loss occurs at SAME time as pattern formation)

45
Q

order to digit loss

A

I, V, II, IV

46
Q

what directions do forelimb and hindlimb rotate leading to final limb position

A

forelimb rotates dorsally
hindlimb rotates ventrally

47
Q

Cingulum, stylopodium, zeugopodium and autopodium in forelimb

A

Scapula and clavicle —> humerus —> radius and ulna —> carpal bones, metacarpal bones and phalanges

48
Q

Cingulum, stylopodium, zeugopodium and autopodium in hindlimb

A

Ox coxae/hip (ileum, pubis, ischium) —> femur —> tibia and fibula —> tarsals, metatarsals and phalanges

Anatomy II (36 decks)

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