Embryology Flashcards Preview

Jason's GI Block > Embryology > Flashcards

Flashcards in Embryology Deck (91):
1

what is a functional disorder?

looks ok, doesn't work well

2

frequency of birth defect?

1:33 (live births only)

3

what is the most common birth defect? frequency?

heart defect 1:200

4

what is the second most common birth defect? frequency?

hypospadias male only
1:300

5

how many cells is a morula?

16

6

whats the diference between a blastocyst and blastocoele?

blastocoele has a cavity

7

blastocyst has two types of cells?

outer trophoblast
inner cell mass

8

What does the trophoblast form?

placenta
extraembryonic structures

9

when does the blastocyst implant?

between 5-10 days

10

inner cell mass splits to?

epiblast
hypoblast

11

epiblast of hypoblast becomes the embryo?

epiblast

12

what is gastrulation, where does it form?

epiblast's formation of the 3 germ layers

13

what layer does the lungs come from?

endoderm

14

what layer does the heart come from?

mesoderm

15

what layer does the pancreas/liver come from?

endoderm

16

T/F? notochord comes from ectoderm?

Nope. mesoderm

17

what's the purpose of notochord?

induces ectoderm above it to form neural plate

18

What forms neural crest?

cells at top of neural tube

19

are the neural tube cells mobile?

yes, migrate away from wide range of structures

20

melanocytes and dentine come from which tissue?

neural crest derivative

21

most of the face comes from mesoderm?

Nope. neural crest

22

example of neural crest defect?

cleft palate

23

dermis comes from which germ layer?

mesoderm

24

pleura peritoneum pericardium comes from which germ layer?

mesoderm

25

whats the opposite of epithelial?

mesenchymal

26

What is mesenchyme?

loose freely moving with Ct inbetween cells

27

urogenital tract comes from which germ layer??

mesoderm

28

3 areas of mesoderm?

paraxial (medial)
intermediate
lateral

29

paraxial mesoderm forms what 3 things?

dermis of skin
axial skeleton
limb muscles

30

intermediate mesoderm forms?

urogenital system

31

lateral mesoderm forms?

heart
wall of gut/respiratory tissues

32

what are somites? which germ layer do they come from?

mesoderm
swellings down paraxial mesoderm

33

what is a somitomere?

pro-somite

34

which pair do semitomere becomes independent somite?

8th pair

35

somite splits into 2 things?

sclerotome (axial skeleton)
dermomyotome

36

dermomyotome splits into?

dermatome
myotome

37

where does the axial skeleton come from? vs. appendicular skeleton?

aial: sclerotome
appendicular: lateral plate

38

human 'gills' are called?

pharyngeal arches

39

pharyngeal arches become?

jaw, face, ear, throat structures and glands

40

when do limbs grow? what layer initates them?

end of 4 week
initiated by mesoderm

41

limb field is what?

patch of mesoderm to make a free limb

42

if remove whole patch vs. part of it?

whole=no limb
part of patch = compensation

43

transplant free limb patch?

ectopic limb

44

How thick is the ectoderm overlying limb bud? why is it significant?

one cell thick
easy to damage or split resulting in diplopodia or other defects

45

how are digits developed?

hands and feet start as discs, sculpted by apoptosis

46

what is syndactyly?

fused fingers

47

what is the most common congenital limb abnormality? frequency?

congenital hip dislocation due to malformed acetabulum
1:500

48

What is amelia? meromelia? caused by?

absent or reduced limbs. Thalidomide

49

what forms the epithelial lining of liver, pancreas?

ENDODERM!

50

What is the Coelom?

holds the viscera

51

Where does coelom come from?

split in lateral mesoderm

52

what does the lateral mesoderm divide into? what do the two become?

splanchnic mesoderm: viscera
somatic mesoderm: muscle

53

describe the folding formation of the coelom?

pulls toether like a bag pull string in 3D

54

Where does the lumen of gut come from?

pinched off from the yolk sac during the coelom folding (tube within a tube)

55

what is the stomodeum?
proctodeum?

membrane covering future mouth and anus

56

ectoderm meets endoderm when what happens to the oral plate?

when it breaks = oral cavity

57

what is the cloacal membrane?

anus seal where ectoderm and endoderm meet

58

What is the allantois?

in body stalk, used to be nitrogenous waste storage in animals

59

what is between allantois and hind gut? what does it do?

urorectal septum that divides rectum from urogenital tract

60

what gives rise to bladder and urogenital tract?

allantois

61

how many pharyngeal pouches form?

4

62

where does most of the heart come from?

lateral splanchnic mesoderm

63

how is the heart developed?

from two endocardial tubes fused together

64

how do you get 4 chambers of heart in embryo?

folding of two fused tube

65

where does heart muscle comes from? germ layer.

mesoderm

66

what's the most common congenital heart defect?

ventricular septal defects

67

congenital heart defect issue in utero?

Nope. usually immediately post birth

68

does the foramen ovale allow left to righ flow of blood?

No. it shouldn't

69

Foregut supplied by?

coeliac artery

70

midgut supplied by?

superior mesenteric

71

hindgut supplied by?

inferior mesenteric

72

describe GIT growth pattern.

lengthens>haipin rotate around axis>elongation>more folding>herniation of GIT

73

When does herniaion of GIT happen?

week 6-7

74

When does GIT retract back into cavity?

week 9

75

What is omphalocele?

no retraction of herniation of GIT

76

retraction but failure to seal wall is?

umbilical hernia

77

frequency of omphalocoele?

1:25 000

78

viscera comes from which germ layers?

initially endoderm which interacts with mesoderm

79

Situs invertus frequency?

1: 10 000

80

What determines left and right in blastocyst?

via primitive groove and cilia that generate right to left current

81

If cilia in primitive node don't work, are you guaranteed to get situs invertus?

Nope 50/50 change

82

intermediate mesoderm forms what system?

urogenital system

83

genital or urinary system forms first?

urinary

84

what are the 3 kinds of kidneys that develop?

pronephros
mesonephros
metanephros

85

kidney from which germ layer?

mesoderm

86

what happens to mesonephric duct in males?

reused and attaches to testes to become the vas deferens

87

kidneys migrate from where to where?

inferior to superior

88

ureters start off where?

mesonephros at bladder

89

penis forms by fusion of?

urogenital folds

90

what happens when urogenital folds don't fuse completely?

hypospadiasis: urethra at base of penis

91

all major organogenesis complete by?

3 months: first trimester