Brainscape's Knowledge GenomeTM

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


See full index

Embryology > Early embryology > Flashcards

Early embryology Flashcards

1
Q

What creates a zygote?

A

Fertilisation between female oocyte and male sperm

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

What happens to zygote?(think expansion)

A

Mitotic cell divisions (cleavage) making daughter cells (blastomeres)

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

What are blastomeres?

A

Daughter cells formed during cleavage of zygote

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

What surrounds the oocyte?

A

Thick glycoprotein layer called the zona pellucida

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

What does sperm bind to?

A

Zona glycoprotein, ZP3, is responsible for sperm binding

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

How do sperm degrade the ZP?

A

Once bound to ZP3 they undergo an acrosome reaction which produces enzymes that can degrade the ZP.

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

At what cell stage of cleavage do cells lose their totipotency?

A

16 cell

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

What stages of the cell cycle do not occur in cleavage?

A

G1/G2

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

What is the cell mass called at the 16 cell stage?

A

Morula

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

What is compaction, what does it do?

A

TJs form between the cells, blastomeres align, separates inner cells from outer cells

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

What is the inner cell mass and the outer cell mass called?

A

Inner cell mass - embryoblast

Outer cell mass - trophoblast

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

What does inner cell mass do?

A

Form embryo proper

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

What does outer cell mass form?

A

Contributes to placenta

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

What causes Inner cell mass to be displaced to one side (what’s this side called)?

A

Fluid accumulation collecting in blastocele cavity - flattens inner cell mass into embryonic pole/embryoblast

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

What is the blastocele?

A

A fluid cavity that forms in the intracellular spaces of the inner cell mass

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

When is implantation?

A

Day 6

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

What happens to uterus after implantation?

A

Endometrial cells adjacent to implanted blastocyst undergo decidual reaction

Uterine lining becomes swollen and vascular - trigger secretion of GFs, glycogen and mucus

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

What is the decidual reaction?

A

Causes uterine lining adjacent to implanted embryo to become swollen and vascular - trigger secretion of GFs, glycogen and mucus

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

What happens to the trophoblast layers after implantation?

A

Trophoblast differentiates into two layers, invade uterine wall

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

What are the two populations of trophoblast?

A

Inner layer of mononuclear cells (cytotrophoblast)

Highly invasive outer layer with no cell boundaries (syncytiotrophoblasts)

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

What sort of trophoblastic cells make hCG?

A

Syncytiotrophoblast

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

What does hCG do?

A

Maintain corpus luteum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What combine to form placenta?

A

Trophoblasts and uterine tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

When is implantation complete?

A

Day 13

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is an ectopic pregnancy (where do most occur)?

A

Implant outside of uterus (mostly in uterine tube)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What do trophoblasts do after invading uterine wall (i.e. ECM)?

A

Break down ECM between endometrial cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the cellular difference between cytotrophoblast and syncytiotrophoblast?

A

Cytotrophoblast is mitotic

Syncytiotrophoblast is multinucleate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Describe what happens to inner cell mass during implantation?

A

Differentiate into epiblast and hypoblast

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is hypoblast adjacent to?

A

Blastocele/blastocyst cavity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What cell shapes are the epiblast vs hypoblast?

A

Hypoblast (cuboidal)

Epiblast (columnar)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Where does amniotic cavity form?

A

Epiblast, splits it into two layers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What happens to epiblast layer after it’s split by amniotic cavity?

A

Epiblast layer adjacent to cyotrophoblasts will form amnion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What does amnion do?

A

Lines amniotic cavity and eventually envelops embryo

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What compromises bilaminar germ disc?

A

External epiblast

Hypoblast

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

When does the bilaminar germ disc form?

A

Week 2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What do cells from hypoblast do?

A

Migrate to form extraembeyonic endoderm and mesoderm (not part of embryo)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What do extraembryonic endoderm and extraembryonic mesoderm do?

A

Migrate from hypoblast to line blastocele cavity which converts cavity to primary yolk sac then secondary yolk sac

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

How does the blood supply to the syncytiotrophobast originate?

A

Vesicles present in the syncytiotrophoblast fuse forming large lacunae

Lacunae become continuous with maternal capillaries (which when dilated become known as sinusoids), maternal blood then enters the lacunae.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

As placenta develops how does cytotrophoblast develop?

A

Cytotrophoblast develops increasing levels of villi invaginating into the syncytiotrophoblast

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Extra-embyronic mesoderm lining cytotrophoblast and amnion is?

A

Extra embryonic somatic mesoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Extra-embyronic mesoderm lining covering yolk sac is?

A

Extra-embyronic splanchnic mesoderm

42
Q

Compare speeds of bilaminar disc comparted to trophoblast?

A

Growth of bilaminar disc slow compared to trophoblast

43
Q

Cavities form in the extraembryonic mesoderm, they?

A

Develop/join form chorionic/extraembryonic cavity

44
Q

What does extraembryonic cavity surround, what’s the exception?

A

Prim yolk sac and amniotic cavity except where germ disc connected to trophoblast by connecting stalk

45
Q

Which 2 cavities form in week 2?

A

Amniotic and yolk sac cavities

46
Q

How does umbilical cord form?

A

Embryo attached to its trophoblastic shell by connecting stalk, stalk develops into umbilical cord

47
Q

What does gastrulation achieve?

A

3 germ layers established and basic body plan emerges.

48
Q

When does gastrulation occur?

A

3rd week

49
Q

How does gastrulation start?

A

Formation of midline structure primitive streak in epiblast

50
Q

What end of bilaminar embryo disc is prim streak found?

A

Caudal end

51
Q

What does primitive streak define?

A

Rostral caudal axis
Left right axis
Dorsal ventral axis

52
Q

Where does primitive node develop relative to prim streak?

A

Rostral end of prim streak

53
Q

What does primitive node do?

A

Neural inducing and organising properties.

54
Q

Where do epiblast cells move (through) in gastrulation?

A

Primitive streak

55
Q

What do first and second wave of epiblastic cells form?

A

First wave: displace hypoblast creates embryonic endoderm

2nd wave: spreads between endoderm and epiblast forms embryonic mesoderm

56
Q

How is embryonic ectoderm formed from epiblast?

A

Epiblast cells that don’t go through streak

57
Q

What structures does ectoderm form?

A

Skin and CNS

58
Q

What does non neural ectoderm form?

A

Skin, tooth enamel, nails

59
Q

What does mesoderm form?

A

Skeletal and connective tissue, blood and muscle

60
Q

What are the 2 types of mesoderm?

A

Axial mesoderm and paraxial mesoderm

61
Q

What does notochord do?

A

Pattern other structures

62
Q

What stage of development does the notochord form in?

A

Gastrulation

63
Q

What cells form the notochord?

A

Endoderm and hypoblast

64
Q

How is the notochord formed?

A

Cells of the notochordal plate (hypoblast and endoderm) detach from the endoderm forming a solid cord of cells.

65
Q

What does the notochord eventually become?

A

Nucleus palposus of the spine

66
Q

What does paraxial mesoderm form in trunk?

A

37 pairs of somites

67
Q

What does paraxial mesoderm form in head?

A

Somitomeres - contribute to head mesenchyme (i.e. muscles of face and bones of skull)

68
Q

What does paraxial mesoderm do either side of notochord?

A

Condenses into segments

69
Q

What are somites?

A

Paired balls of paraxial mesoderm

70
Q

What do somites differentiate into?

A

Sclerotome

Dermamyotome (dermatome and myotome)

71
Q

What part of somite is sclerotome formed from?

A

Ventromedial parts of somite

72
Q

What do sclerotome cells do (where do they move and form)?

A 
Move medially forming:
Vertebral body (surrounding notochord)

Verebral arch (surrounds neural tube)

Annulus fibrosis

Ribs

73
Q

What does dermatome contribute to?

A

Dermis (fat and connective tissue of neck and back)

74
Q

What does myotome differentiate to?

A

Muscle

75
Q

What does intermediate mesoderm do?

A

Differentiate into urogenital structures

76
Q

What does lateral plate mesoderm line?

A

Divide to line intraembryonic coelom

77
Q

What does lateral plate mesoderm form?

A

Somatic/parietal mesoderm

Splanchnic /visceral mesoderm

78
Q

What is somatic/parietal mesoderm adjacent to?

A

Ectoderm

79
Q

What does splanchnic/visceral mesoderm do?

A

Forms gut wall and vascular system

80
Q

What is splanchnic mesoderm adjacent to?

A

Endoderm

81
Q

What does somatic/parietal mesoderm form?

A

Dermis and limbs

82
Q

Where is mesoderm absent in body (2 points) i.e. endoderm direct contact with ectoderm?

A

Buccopharngeal membrane (rostrally) and cloacal membrane (caudal)

83
Q

What do buccopharyngeal membrane and cloacal membrane mark?

A

End of gut tube

84
Q

Each somite forms its own…

A

Sclerotome, myotome and dermatome

85
Q

Each myotome and dermatome retains its…

A

Innervation from its segment of origin regardless of where they migrate

86
Q

What does endoderm form?

A

Gut tube, liver, lungs

87
Q

How does notochord pattern neural tube?

A

Shh, pattern along dorsal ventral axis

88
Q

What is a teratogen?

A

Substance that causes malformation in embryo/fetus

89
Q

What is a critical period?

A

Period of development during which organ/system is susceptible to genetic/environmental factors

90
Q

When generally is the most sensitive period for teratogenic effects?

A

3-8 weeks

91
Q

Does a teratogen always have an effect on embryonic development, why?

A

No, teratogen may be administered before/after critical sensitive period

92
Q

What is situs inversus?

A

Position of major organs is reversed

93
Q

What axis of embryonic disc grows in gastrulation?

A

Rostral caudal axis

94
Q

What direction do cells migrate to form primitive streak?

A

Rostrally

95
Q

In what direction does primitive streak shorten/regress?

A

Towards caudal end

96
Q

How does sclerotome fuse to form vertebrae?

A

The lower half of one sclerotome fuses with the upper half of the adjacent one to form each vertebral body.

97
Q

Embryonic germ layer from which the notochord is derived

A

Epiblast

98
Q

What can the notochord be classed as?

A

Mesoderm (axial)

99
Q

Embryonic ectoderm gives rise to the…

A

Brain

100
Q

Does the trophoblast become anything to do with the foetus?

A

No

Embryology (10 decks)

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