Brainscape's Knowledge GenomeTM

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


See full index

S2 Respiratory System > Embryology 1,2/ > Flashcards

Embryology 1,2/ Flashcards

1
Q

when is the blastocyst formed?

A

day 5-6

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

which hormones help the endometrium grow?

A

progesterone and oestrogens

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

where does fertilisation happen most of the time?

A

distal end of fallopian tube

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

is the uterin tube capable of carrying out a pregnancy? what could happen?

A

no, could damage tube and this has complications

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

what cavity is on top?

A

amniotic

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

what cavity is on the bottom?

A

yolk sac

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

when does implantation happen?

A

2nd week

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

how many surfaces does the placenta have?

A

2 (maternal surface and fatal surface)

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

how do you know when the gastrulation process is complete?

A

3 layers are present

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

where does the notochord form?

A

mesoderm

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

how does the notochord act on the primitive line?

A

sends signals

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

what happens to the primitive line? what’s its new name?

A

thickens and becomes the neural plate

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

what happens to the neural plate?

A

sinks down and forms a tube (separates from the ectoderm)

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

what layer produces somites?

A

mesoderm

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

what does the mesoderm divide into?

A

3 plates on each side (lateral, intermediate, paraxial)

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

what happens to the para axial mesoderm?

A

it segments

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

how many pairs of somites do they segment in?

A

about 43

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

what happens to the lateral late mesoderm?

A

splits between the somatic and splanchnic side

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

NEW when is the pre-embryonic phase?

A

0-3 weeks

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

when is the embryonic phase ?

A

4-8 weeks

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

when is the foetal phase?

A

9-40 weeks

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

TRUE/FALSE spermatogenesis and oogenesis are made through mitosis

A

FALSE meiosis

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

what does spermatogenesis start with? end with?

A

starts with a spermatogonium (46 chromosomes), ends with 4 sperms (22+X or 22+Y)

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

what does oogenesis start with? end with?

A

starts with an oogonium (46 chromosome), ends with 3 polar bodies (which degenerate) and a 1 ovum (22+X)

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

what is the other name for sperm and ovum?

A

gametes

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

can a sperm penetrate the female gamete if it’s the only sperm around?

A

no, fertilisation requires that several sperms surround the ovum

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

what happens during fertilisation?

A

(pro)nucleus of sperm enters and fuses with the (pro)nucleus of ovum to give a diploid cell

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

what is the diploid cell formed during fertilisation called?

A

zygote

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

what happens during week 1 of pre-embryonic phase?

A
  • zygote is formed; divides to form a blastocyst

- moves through uterine tube, to reach uterine cavity

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

how many chromosomes does the zygote cell have?

A

46 (diploid)

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

why is it genetically unique?

A

because it has 23 of mum’s & 23 of dad’s chromosomes

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

which parent does the mitochondria and organelles come from?

A

the mum

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

what structure is formed by the first cells of the division of the zygote?

A

morula (solid ball of cells)

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

what are examples of mitochondrial diseases?

A

Leber’s hereditary optic (neuropathy -> blindness)

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

in what ways are mitochondrial diseases transmitted?

A

inherited from mother

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

what happens as the morula increases in size?

A

getting nutrition to the central core of cells becomes difficult

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

how is this issue dealt with?

A

a cavity called the blastocystic cavity develops

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

what is the outer lining of cells called?

A

the trophoblast

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

what happens to the rest of the cells?

A

they accumulate at one end to form an inner cell mass

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

does the speed of the first divisions remain constant?

A

no (divisions accelerate at the beginning, 36h for first, 24h for 2nd, 12h for 3rd)

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

what happens in the ovary before fertilisation?

A

ovum is released from ovary

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

by what time is the blastula ready to implant?

A

5-6 days

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

where does the blastula implant?

A

in the uterine cavity

44
Q

what does the dividing zygote/ morula/ blastocyst rely on to move from fallopian tube to uterine cavity?

A

healthy ciliated epithelium in the fallopian tube

45
Q

what is an ectopic pregnancy?

A

when the implantation happens outside the uterine cavity

46
Q

what happens during week 2 of pre-embryonic phase?

A
  • implantation, placenta begins to develop
  • cells form a bilaminar disc
  • sacs, membranes and cord to nourish the human conceptus (baby) start to form
47
Q

where does implantation usually occur?

A

uterine endometrial layer

48
Q

when might implantation start in the early cases?

A

day 6 of 1st week

49
Q

when does implantation usually start?

A

at 7 days

50
Q

what happens during implantation?

A

blastocyst begins to burrow into the uterine wall (endometrium)

51
Q

what cells does the chorion come from?

A

trophoblast cells

52
Q

in how many layers does the trophoblast divide into?

A

2

53
Q

what are chorionic villi?

A

finger like processes coming from the 2 layered chorion

54
Q

what does the chorion do?

A
  • implantation process (chorionic villi)
  • forms part of the placenta in due course
  • secretes human chorionic gonadotropin (HCG) (used to detect pregnancy)
55
Q

what is the muscle layer surrounding the uterus called?

A

myometrium

56
Q

what is the other name for endometrium?

A

decidua

57
Q

what is the decidua basalis?

A

the base of the endometrium (with extra maternal blood vessels)

58
Q

what secrets hCG?

A

human chorionic gonadotropin is secreted by chorion to help maintain the endometrium

59
Q

till when do hCH levels of maternal blood and urine increase?

A

till around 12 weeks gestation

60
Q

what happens to the inner cell mass?

A

form a 2-layered flat disc called the bilaminar disk

61
Q

what 2 cavities begin to form after the bilaminar disk forms?

A

amniotic cavity (A) and yolk sac (Y)

62
Q

what are the main function of the placenta?

A
  • foetal nutrition
  • transport of waste and gases
  • immune (etc)
63
Q

what two surfaces make up the placenta?

A

foetal part - smooth with foetal blood vessels and end of umbilical cord
maternal part - decidua basalis of endometrium, rough and has maternal blood vessels

64
Q

by when does placenta mature?

A

18-20 weeks

65
Q

how much does the placenta weigh as opposed to the foetus?

A

1/6

66
Q

how do you get fraternal/ dizygotic twins?

A

2 ova releases, 2 sperms -> 2 separate zygotes, 2 different genetic makeups, 2 placentae

67
Q

how do you get identical/ monozygotic?

A

1 ovum, 1 sperm, 1 zygote initially -> divides into 2 and each cell develops into a different embryo, same genetic makeup share one placenta; (might/ might not share amnionic and chorionic sac)

68
Q

what happens during week 3?

A
  • formation of germ layers (gastrulation)
  • formation of neural tube (neurulation)
  • development of somites
  • early development of cardiovascular system
69
Q

where is the primitive streak formed?

A

formed in the midline of the epiblast by the dipping in of cells (invagination)

70
Q

what happens to the embryo once the primitive streak forms?

A

the AXIS of the embryo is formed (it has a front and a back)

71
Q

what is gastrulation?

A

formation of 3 germ layers

72
Q

how is the 3rd germ layer formed?

A

epiblast cells migrate into space between epiblast and hypoblast layers, cells then displace hypoblast, forming 3 germ layers

73
Q

what are the 3 germ layers called?

A

ectoderm, mesoderm and endoderm

74
Q

what is the other name for the 3 germ layers?

A

trilaminar disc

75
Q

how have the cells changed at this point?

A

they are specialised from this point on

76
Q

summary of the different changes in week 3:

A

inner cell mass of blastocyst -> bilaminar disc, primitive streak -> cells from primitive streak invaginate -> displace hypoblast -> endoderm, mesoderm, ectoderm

77
Q

how does the notochord form?

A

ectoderm invaginates (primitive streak), the cells then sink down to form a solid tube in the mesoderm

78
Q

what is neurulation?

A

formation of the neural tube

79
Q

how does the neural tube form?

A

notochord induces ectodermal cells in the midline to form a neural tube, which is actually just a thickening of the ectoderm forming a neural plate, which then invaginates in between the ectoderm and the mesoderm

80
Q

where do somites develop?

A

mesoderm

81
Q

what induces the mesoderm to thicken?

A

neutral tube

82
Q

what does the mesoderm separate into?

A

paraxial mesoderm, intermediate mesoderm and lateral plate mesoderm

83
Q

what happens to the lateral plate mesoderm?

A

splits to form a somatic and splanchnic mesoderm

84
Q

what is the space formed in between the somatic and splanchnic mesoderm called?

A

intra-embryonic coelom

85
Q

which part of the mesoderm gives the somites?

A

paraxial mesoderm

86
Q

which part of the mesoderm gives the urogenital system?

A

intermediate plate mesoderm

87
Q

which part of the mesoderm die body cavity and covering?

A

lateral plate mesoderm

88
Q

what happens in the embryonic/ organogenetic period? (4-8 weeks)

A
  • folding into a tube (lateral folds) which started in 3rd week completes
  • neural tube - forebrain, midbrain, hindbrain and spinal cord development
  • heart starts to beat on day 24
  • gut formation from endoderm
  • urogenital system formation from intermediate mesoderm
  • body cavities from lateral plate mesoderm
  • 43 pairs of somites form in the paraxial mesoderm and differentiate further
  • limb buds form
  • neck development - pharyngeal arches
89
Q

how does the lateral folding of embryo happen?

A

endoderm becomes round, splanchnic and somatic mesoderm go around endoderm, ectoderm covers them all up

90
Q

which is more peripheral? somatic or splanchnic mesoderm?

A

somatic

91
Q

how do the somites further develop?

A

each somite divides into 3: dermatome, myotome, sclerotome

92
Q

what will happen to the dermatome?

A

becomes the dermis of the skin

93
Q

what will happen to the myotome?

A

becomes the muscles

94
Q

what will happen to the sclerotome?

A

becomes the bones including vertebrae

95
Q

what is teratology?

A

study of when things go wrong during development

96
Q

what are teratogens?

A

environmental factors that cause abnormal development

97
Q

what virus causes congenital rubella syndrome? under which conditions?

A

german measles when pregnant

98
Q

what chemical compound provokes malformed limbs when administered to the pregnant mother?

A

thalidomide

99
Q

how frequently is the cause of abnormal development environmental factors?

A

10% of cases

100
Q

what are the causes of environmental-caused abnormal development?

A
  • drugs (prescription/others)
  • alcohol/ tobacco
  • infections agents: ToRCH (toxoplasma, rubella, cytomegalovirus, herpes) can transfer through placenta and affect developing embryo
  • radiations
101
Q

how frequently is the cause of abnormal development genetic factors?

A

10% of cases

102
Q

what are the causes of genetically-caused abnormal development?

A
  • too many/ too few chromosomes (Turner, Down’s)
  • structural changes (deletion of genes, segments of chromosomes)
  • causes: increased maternal age, damage from environmental factors such as radiation (ex: Xrays)
103
Q

when (during the pregnancy) is the sensibility to teratogens the greatest?

A

weeks 1-2: low
weeks 3-8: highest
weeks 9-38: decreasing

104
Q

when (during the pregnancy) is the risk of death due to teratogens the greatest?

A

weeks 1-2: high risk

105
Q

what does the risk posed by a teratogen depend on?

A
  • exposure during critical periods of development
  • dosage of drug/ chemical/ factor
  • genetic constitution of embryo i.e. some more susceptible than others at equivalent doses etc
106
Q

how do you diagnose malformations prenatally?

A

blood (AFP), ultrasound scan - 12 week anomaly scan, invasive tests: chorionic villus sampling and amniocentesis

107
Q

how do you diagnose malformations postnatally?

A

hip stability, testes (proper descent), fingers and toes, hearing

S2 Respiratory System (43 decks)

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