Brainscape's Knowledge GenomeTM

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


See full index

Z OLD Tissues of the Body > The Pre-Embryonic Period > Flashcards

The Pre-Embryonic Period Flashcards

1
Q

<p>How does once cell become a multicellular body?</p>

A

<p>Growth, Morphogenesis, Differentiation</p>

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

<p>What does morphogenesis involve?</p>

A

<p>Creating lots of cells in the right place at the right time</p>

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

<p>What is the result of morphogenesis?</p>

A

<p>The development of form and structure</p>

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

<p>Why is differentiation needed?</p>

A

<p>For specialisation for function</p>

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

<p>What does differentiation allow?</p>

A

<p>Certain groups of cells to specialise for a common function</p>

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

<p>What are the 3 stages from fertilisation to birth?</p>

A

<p>- Pre-embryonic

- Embryonic
- Fetal</p>

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

<p>When is the pre-embryonic period?</p>

A

<p>Weeks 1-2</p>

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

<p>When is the embryonic period?</p>

A

<p>Weeks 3-8</p>

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

<p>Why is the embryonic period such a critical period?</p>

A

<p>All structures and systems of the body are made</p>

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

<p>When is the foetal period?</p>

A

<p>Weeks 9-38</p>

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

<p>What happens in the foetal period?</p>

A

<p>The focus is on growth and physical maturation of systems</p>

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

<p>When are pregnancy weeks calculated from?</p>

A

<p>LMP, i.e. conception weeks +2</p>

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

<p>How long is a term pregnancy?</p>

A

<p>40 weeks</p>

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

<p>What happens in the pre-embryonic period?</p>

A 
<ul>
	<li>Cleavage</li>
	<li>Compaction</li>
	<li>Implantation begins</li>
</ul>
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

<p>What is happening in cleavage?</p>

A

<p>Mitotic division</p>

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

<p>Why is cleavage significant?</p>

A

<p>Because have established a new individual</p>

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

<p>What is formed from cleavage?</p>

A

<p>Morula</p>

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

<p>What is the morula?</p>

A

<p>A clump of cells</p>

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

<p>What happens in compaction?</p>

A

<p>The formation of a blastocyst</p>

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

<p>What is implantation?</p>

A

<p>The process by which the blastocyst makes contact with the endometrium of the uterus</p>

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

<p>What does implantation begin?</p>

A

<p>The establishment of the pregnancy</p>

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

<p>Where is the oocyte released from?</p>

A

<p>The ovary</p>

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

<p>What happens to the oocyte once it’s been released?</p>

A

<p>It travels along the Fallopian tubes</p>

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

<p>Where is the oocyte fertilised?</p>

A

<p>Ampulla</p>

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

<p>What fertilises the oocyte?</p>

A

<p>Sperm</p>

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

<p>What is the ampulla of the fallopian tubes?</p>

A

<p>The fan bit just above the ovary</p>

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

<p>What is the fertilised oocyte called?</p>

A

<p>The zygote</p>

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

<p>Where is the ideal site for implantation?</p>

A

<p>The posterior uterine wall</p>

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

<p>What does the zygote need to do before it can implant?</p>

A

<p>Continue to travel alone the fallopian tube to get where it needs to be to establish the pregnancy</p>

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

<p>How long is an oocyte viable for?</p>

A

<p>1 day</p>

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

<p>How long is sperm viable for?</p>

A

<p>3 days</p>

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

<p>What happens immediately after fertilisation?</p>

A

<p>Sperm is excluded due to a complex chemical reaction</p>

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

<p>When does cleavage begin?</p>

A

<p>30 hours after fertilisation</p>

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

<p>What does cleavage result in?</p>

A

<p>2 blastomeres of equal size</p>

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

<p>What is the zona pellucida?</p>

A

<p>A glycoprotein ‘shell’</p>

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

<p>What is the result of the presence of the zona pellucida?</p>

A

<p>The blastomeres are about half the size of the oocyte, as the cell prevents it from expanding</p>

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

<p>What has happened by day 3 post fertilisation?</p>

A

<p>The morula has formed</p>

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

<p>What feature does each cell have at the morula formation stage?</p>

A

<p>They are totipotent</p>

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

<p>What is meant by the cells being totipotent?</p>

A

<p>They have the capacity to become any cell type</p>

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

<p>What happens in assisted reproductive techniques?</p>

A

<p>The oocytes are fertilised in vitro, and allowed to divide to the 4- or 8- cell stage. The morula is then transferred into the uterus</p>

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

<p>What is PGD?</p>

A

<p>When a cell is removed from the morula and tested for serious heritable conditions prior to the transfer of the embryo into the mother</p>

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

<p>What is compaction?</p>

A

<p>Formation of the first cavity</p>

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

<p>What is the first cavity formed?</p>

A

<p>The blastocyst</p>

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

<p>How is the blastocyst formed?</p>

A

<p>The cells of the morula are secreting tiny amounts of tissue fluid. Together, collect a sufficient amount that it collects, and one clump of cells pushes to one side, giving a space</p>

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

<p>What does the formation of the blastocyst give?</p>

A

<p>2 groups of cells</p>

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

<p>What is the inner group of cells called?</p>

A

<p>Embryoblast</p>

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

<p>What is the outer group of cels called?</p>

A

<p>Trophoblast</p>

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

<p>What happens to the inner group of cells of the blastocyst?</p>

A

<p>It goes on to give the embryo</p>

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

<p>What happens to the outer cells of the blastocyst?</p>

A

<p>They go on to produce the supporting tissues</p>

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

<p>What tissues support the embryo during pregnancy?</p>

A

<p>#NAME?</p>

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

<p>Why can cells produced by the first divisions after fertilisation become inner or outer cell mass?</p>

A

<p>Because they are all totipotent, so they have the capacity to become any cell type</p>

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

<p>What are cells after compaction?</p>

A

<p>Pluripotent</p>

53
Q

<p>What is meant by pluripotent?</p>

A

<p>Cells have the capacity to become one of many cell types</p>

54
Q

<p>What potential are pluripotent cells said to have?</p>

A

<p>Multi-lineage potential</p>

55
Q

<p>What do the inner cell mass cells have the capacity to do?</p>

A

<p>Become any cell in the human body</p>

56
Q

<p>What happens at day 5 post fertilisation?</p>

A

<p>Hatching</p>

57
Q

<p>What is meant by hatching?</p>

A

<p>The blastocyst hatches from the zona pellucida</p>

58
Q

<p>Why must the blastocyst hatch?</p>

A

<p>Up until now, the zona pellucida remains in tact, meaning it becomes quite restrictive, so we must get rid of it</p>

59
Q

<p>What is the result of hatching?</p>

A

<p>The blastocyst is no longer constrained, and so is free to enlarge</p>

60
Q

<p>What can the blastocyst do once it’s hatched?</p>

A

<p>Interact with the uterine surface to implant</p>

61
Q

<p>When does implantation begin?</p>

A

<p>Day 6-7</p>

62
Q

<p>How long does implantation run for?</p>

A

<p>A very long time- not complete until the end of the first trimester (~3 months)</p>

63
Q

<p>What is the conceptus?</p>

A

<p>All the products of conception- the embryo and all its tissues</p>

64
Q

<p>How many cells does the conceptus have at implantation?</p>

A

<p>107</p>

65
Q

<p>How many cells of the conceptus at implantation will make the embryo?</p>

A

<p>8</p>

66
Q

<p>How many cells of the conceptus at implantation will contribute to the development of foetal membrane?</p>

A

<p>99</p>

67
Q

<p>Why is it important that foetal membranes are established?</p>

A

<p>It ensures that we can establish and maintain the pregnancy</p>

68
Q

<p>Where does the conceptus implant?</p>

A

<p>Onto the uterine epithelium, which lines the uterine stroma</p>

69
Q

<p>What development has priority at the very earliest stages?</p>

A

<p>Placenta</p>

70
Q

<p>What important process occurs in week 2?</p>

A

<p>Differentiation</p>

71
Q

<p>Where do two distinct cell layers emerge from?</p>

A

<p>The outer cell mass</p>

72
Q

<p>What distinct cell layers emerge from the outer cell mass?</p>

A

<p>- Syncytiotrophoblast

| - Cytotrophoblast</p>

73
Q

<p>What is the syncytiotrophoblast good for?</p>

A

<p>Transporting</p>

74
Q

<p>What is purpose of the cytotrophoblast?</p>

A

<p>Allows the syncytiotrophoblast grow and increase in SA</p>

75
Q

<p>What does the inner cell mass develop into?</p>

A

<p>A bilaminar disc</p>

76
Q

<p>What does the bilaminar disc consist of?</p>

A

<p>#NAME?</p>

77
Q

<p>In summary, what has happened by the end of the second week?</p>

A

<p>#NAME?</p>

78
Q

<p>What are the two cavities of the embryo by the end of week two?</p>

A

<p>#NAME?</p>

79
Q

<p>What is the name of the sac supporting the embryo?</p>

A

<p>The chorionic cavity</p>

80
Q

<p>What is the amniotic sac formed from?</p>

A

<p>Spaces within the epiblast</p>

81
Q

<p>What can implantation cause?</p>

A

<p>A small amount of bleeding</p>

82
Q

<p>Why might implantation cause a small amount of bleeding?</p>

A

<p>Because it’s in invasive process</p>

83
Q

<p>Why is implantation an invasive process?</p>

A

<p>The conceptus has to break through the endothelial lining</p>

84
Q

<p>What must happen once the conceptus has broken through the endothelial lining?</p>

A

<p>The lining must be repaired</p>

85
Q

<p>How is the endothelial lining repaired?</p>

A

<p>Using a fibrin plug</p>

86
Q

<p>What is meant my implantation being interstitial?</p>

A

<p>The two tissues have a very close relationship- they are embedded</p>

87
Q

<p>Where does the conceptus implant?</p>

A

<p>Within the uterine stroma</p>

88
Q

<p>Why does the conceptus implant within the uterine stroma?</p>

A

<p>Because then it has access to all glands</p>

89
Q

<p>What does implantation establish?</p>

A

<p>Maternal blood flow within the placenta- the basic structural unit of materno-fetal exchange</p>

90
Q

<p>What change does implantation mark?</p>

A

<p>The support for embryo changes from histiotrophic to haemotrophic</p>

91
Q

<p>What is meant by histiotrophic?</p>

A

<p>Support for tissues based on simple diffusion</p>

92
Q

<p>Why must support for the embryo change from histiotrophic?</p>

A

<p>Because staying with this would drastically limit the size that it could grow</p>

93
Q

<p>What is meant by haemotrophic?</p>

A

<p>Relying on support from maternal circulatory system</p>

94
Q

<p>Why does the basic structural unit for materno-fetal exchange have to be within the placenta?</p>

A

<p>To allow for gas exchange, absorption of nutrients and removal of waste products from the foetus</p>

95
Q

<p>Give 4 conditions linked to implantation defects</p>

A

<p>- Interuterine growth restriction (IUGR)

- Pre-eclampsaia
- Ectopic pregnancy
- Placenta praevia</p>

96
Q

<p>What kind of defect causes ectopic pregnancy and placenta praevia?</p>

A

<p>When the conceptus implants at the wrong site</p>

97
Q

<p>Where does the conceptus implant in an ectopic pregnancy?</p>

A

<p>At a site other than the uterine body, most commonly the Fallopian tubes</p>

98
Q

<p>What are the two types of ectopic pregnancy?</p>

A

<p>#NAME?</p>

99
Q

<p>What is the problem with ectopic pregnancy?</p>

A

<p>It can very quickly become a life threatening emergency, as it can cause haemorrhage</p>

100
Q

<p>Where does the conceptus implant in placenta praevia?</p>

A

<p>In the lower uterine segment</p>

101
Q

<p>What is the problem with placenta praevia?</p>

A

<p>It can cause haemorrhage in pregnancy</p>

102
Q

<p>Why can placenta praevia cause haemorrhage?</p>

A

<p>If implantation occurs very near the point of exit, the placenta can grow across, causing the mother to bleed out</p>

103
Q

<p>What does placenta praevia necessitate?</p>

A

<p>C-section delivery</p>

104
Q

<p>What happens on day 9 post fertilisation?</p>

A

<p>- Embryonic pole develops

| - Abembryonic pole develops</p>

105
Q

<p>What causes the development of the embryonic pole?</p>

A

<p>The rapid development of the syncytiotrophoblast</p>

106
Q

<p>What happens once the abembryonic pole has been formed?</p>

A

<p>The primitive yolk sac is formed</p>

107
Q

<p>What is the significance of the formation of the primitive yolk sac?</p>

A

<p>You then have an embryo with two cavities</p>

108
Q

<p>What is the yolk sac membrane in contact with?</p>

A

<p>The cytotrophoblast layer</p>

109
Q

<p>What are present in the syncytiotrophoblast?</p>

A

<p>Lacunae</p>

110
Q

<p>What are lacunae?</p>

A

<p>Spaces opening up</p>

111
Q

<p>What is the purpose of lacunae?</p>

A

<p>They allow for rapid increasing SA</p>

112
Q

<p>What happens on day 11 post fertilisation?</p>

A

<p>Primitive yolk sac membrane pushed away from the cytotrophoblast layer</p>

113
Q

<p>What pushes the cytotrophoblast layer away from the primitive yolk sac membrane?</p>

A

<p>An acellular extraembryonic reticulum</p>

114
Q

<p>What later happens to the acellular extraembryonic reticulum?</p>

A

<p>Its converted into extraembryonic mesoderm by cellular migration</p>

115
Q

<p>What happens on day 12 post fertilisation?</p>

A

<p>Maternal sinusoids are invaded by syncytiotrophoblast</p>

116
Q

<p>What happens once the maternal sinusoids have been invaded by the syncytiotrophoblast?</p>

A

<p>The lacunae become continuous with the sinusoids</p>

117
Q

<p>What does maternal sinusoids being invaded by syncytiotrophoblast begin?</p>

A

<p>Uteroplacental circulation</p>

118
Q

<p>What is the uterine stroma preparing for when the maternal sinusoids are invaded by syncytiotrophoblast?</p>

A

<p>Support of the embryo</p>

119
Q

<p>What happens day 13 post fertilisation?</p>

A

<p>Formation of the secondary yolk sac</p>

120
Q

<p>Where does the secondary yolk sac come from?</p>

A

<p>Pinches off from the primitive yolk sac</p>

121
Q

<p>What happens day 14 post fertilisation?</p>

A

<p>Spaces within the extra-embryonic mesoderm merge</p>

122
Q

<p>What is formed when spaces within the extra-embryonic mesoderm merge?</p>

A

<p>The chorionic cavity</p>

123
Q

<p>What suspends the embryo and its cavities?</p>

A

<p>The connecting stalk</p>

124
Q

<p>What is the connective stalk made up of?</p>

A

<p>A column of mesoderm and future umbilical cord</p>

125
Q

<p>What can bleeding be confused for at day 14?</p>

A

<p>Menstrual bleeding</p>

126
Q

<p>What % of zygotes are lost within the first 2-3 weeks?</p>

A

<p>~50%</p>

127
Q

<p>What % of diagnosed pregnancies miscarry?</p>

A

<p>15%</p>

128
Q

<p>What % of women suffer from recurrent miscarriages?</p>

A

<p>1%</p>

129
Q

<p>What is meant by recurrent miscarriages?</p>

A

<p>Miscarriages in 3 consecutive pregnancies</p>

Z OLD Tissues of the Body (19 decks)

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