Embryology Flashcards

1
Q

Between what weeks is the embryonic phase?

A

0-3 weeks

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

Between which weeks is the embryonic phase?

A

4-8 weeks

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

Between which weeks is the foetal phase?

A

9-40 weeks

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

What is spermatogenesis?

A

The formation of sperm

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

What is oogenesis?

A

The formation of the ovum

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

By what cellular process do gametes divide?

A

Meiosis

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

What is the spermatogonium?

A

The cell that produces sperm

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

What is the oogonium?

A

The cell that produces the ovum

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

What is the cell formed at fertilisation called?

A

The zygote

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

Does just one sperm surround the ovum?

A

No several

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

How many sperm penetrate the egg?

A

Just one

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

What part of the sperm penetrates the ovum?

A

The pro-nucleus

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

Why does mitochondrial inheritance come from the mother?

A

Because the sperms organelles are pushed out at fertilisation

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

What is the first cell in the body?

A

The zygote

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

Is the zygote diploid or haploid?

A

Diploid

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

How does the zygote divide?

A

By mitosis

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

What is the morula?

A

Ball of cells that have divided from the zygote

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

Why does a cavity develop in the morula?

A

To get nutrients to the central core of the cells

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

What is the cavity that develops in the morula known as?

A

Blastocystic cavity

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

What does the morula become?

A

A blastocyst

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

What is the outer lining of cells on the blastocyst called?

A

Trophoblast

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

How does the egg or fertilised zygote move along the oviduct?

A

Ciliated epithelium moves it along

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

How long does the first cell division take?

A

36 hours

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

If cilia function in the fallopian tubes is faulty what can occur?

A

An ectopic pregnancy

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

How many days does it take fir the blastula to have formed ready to implant in the uterine cavity?

A

5 or 6

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

Where does implantation occur?

A

In the endometrial layer

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

What is the function of the chorion?

A

To help the embryo burry into the endometrium
To go on and form part of the placenta
To secrete HCG

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

What does HCG hormone do?

A

Tells the body to keep producing oestrogen and progesterone to maintain the endometrium
Also is used to test for pregnancy

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

How does the chorion aid implantation?

A

By creating finger like projections (villi)

30
Q

What are the 2 layers of the Bilaminar disc called?

A

Epiblast

Hypoblast

31
Q

What cavity lies above the epiblast?

A

Amniotic cavity

32
Q

What cavity lies below the hypoblast?

A

Yolk Sac

33
Q

Why does the allantoic begin to get larger?

A

Because more and more waste products are dumped there

34
Q

Why does the yolk sac get smaller?

A

Because the nutrients are being used up

35
Q

Does maternal and foetal blood ever mix?

A

No

36
Q

How does the transfer of nutrients and waste occur between mum and baby if there blood do not mix?

A

By diffusion

37
Q

What are the main functions of the placenta?

A

Foetal nutrition
Transport of waste and gases
Immune ect

38
Q

Why is the foetal part of the placenta smooth?

A

Because it is lined by the amniotic sac

39
Q

How much does the placenta weigh?

A

1/6 of the foetus

40
Q

By what weeks has the placenta matured?

A

18-20

41
Q

What are fraternal twins?

A

2 ova
2 sperms
2 separate zygotes
Different genetic makeup

42
Q

What are identical twins?

A

When there is 1 ovum
1 sperm
1 zygote initially
Divides into 2 and each develops into a different embryo

43
Q

Which type of twins can run in families?

A

Fraternal

When the mother releases 2 ova

44
Q

What is gastrulation?

A

The formation of the germ layers

45
Q

What is neurulation?

A

Formation of the neural tube

46
Q

How is the primitive streak formed?

A

Formed in the midline of the epiblast

By the dipping in of cells (invagination)

47
Q

What are the 3 germ layers upper to lower?

A

Ectoderm
Mesoderm
Endoderm

48
Q

Are the germ cells specialised?

A

Yes

49
Q

Cells from which germ layer continue to divide?

A

Ectoderm

50
Q

What is the notochord?

A

Solid tube of cells formed from the dividing ectoderm

51
Q

What does the notochord send?

A

Signals that induce midline ectodermal cells to form a neural tube

52
Q

How is a neural tube formed?

A

Signals are sent by the notochord that stimulate the midline of the ectoderm to divide and form a neural tube

53
Q

What does the neural tube induce?

A

The mesoderm to thicken

54
Q

What 3 parts does the mesoderm separate into?

A

Paraxial mesoderm
Intermediate plate mesoderm
Lateral plate mesoderm

55
Q

What does the lateral plate mesoderm split to form?

A

Somatic and splanchnic mesoderm

56
Q

On which day does the heart start to beat?

A

Day 24

57
Q

What does the ectoderm go on to form?

A

Epidermis of skin

Neural tube

58
Q

What does the endoderm go on to form?

A

Gut

Respiratory

59
Q

What does the paraxial mesoderm go on to form?

A

Somites

60
Q

What does the intermediate plate mesoderm go on to form?

A

Urogenital system

Kidneys, reproductive

61
Q

What does the lateral plate mesoderm go on to form?

A

Peritoneum
Pleura
Body cavities

62
Q

What is the peritoneum?

A

The membrane surrounding the heart

63
Q

Where do the somites run along?

A

The primitive streak

64
Q

What do the myotomes form?

A

Muscles

65
Q

What do the dermatomes form?

A

Dermis of skin

66
Q

What do the sclerotomes form?

A

Bones

67
Q

What 3 sections do the somites divide into?

A

Dermatome
Myotome
Sclerotome

68
Q

What is teratology?

A

The study of when things go wrong during foetal development

69
Q

What are teratogens?

A

Environmental factors that cause abnormal development

70
Q

What genetic factors can cause things to go wrong with foetal development?

A

Too many/few chromosomes
Structural changes in chromosomes
Increased maternal age

71
Q

When is the highest risk of teratology?

A

Weeks 4-8

72
Q

What drug fro? the 60s caused foetal abnormalities?

A

Thalidomide