Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Embryology > Lecture 2 (gametogensis -> gastrulation/end of wk 3) > Flashcards

Lecture 2 (gametogensis -> gastrulation/end of wk 3) Flashcards

1
Q

Why is a zygote protected from exposure in the 1st two weeks of development?

A

implantation doesn’t occur until roughly 2 weeks after fertilization (not connected to mother yet)

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

What timeframe is the fetus most sensitive to exposures?

A

weeks 3-8

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

Where/as what do germ cells originate?

A

outside of the gonads

primordial germ cells

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

Where are germ cells formed? Where do they travel?

A

in the epiblast in 2nd wk

travel to the wall o the yolk sac

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

When do the germ cells arrive at the gonads?

A

by the 5th week of pregnancy

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

primordial germ cells migrate to where after gastrulation?

A

they migrate to the somatic region of the kidney and then differentiate thank to their somatic cell partners

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

during what period do oogonia increase in number? what process is this?

then what happens?

A

2nd and 5th month of pregnancy - mitosis

atresia until menopasuce

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

When do spermatogonia undergo mitotic arrest? When do they resume division?

A

perinatally

at puberty

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

How long does it take for sperm to mature?

A

64-74 days

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

What cells hold all spermatogonia?

A

sertoli cells

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

Which type of spermatogonia undergo meiosis?

A

Type B

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

Once Type B spermatogonia undergo meiosis I you have ->

A

secondary spermatocytes

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

Secondary spermatocytes undergo ________ to form ->

A

meiosis II

4 haploid spermatids

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

spermatids mature and become ->

A

spermatozoans

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

How long does spermatogenesis take? What is the beginning and end?

A

64 days

spermatogonia -> spermatozoa

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

Primary oocytes are frozen in ->

A

Meiosis I

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

How many follicles mature every month in females? When does this begin? How many reach full maturation?

A

15-20

after puberty

only one

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

When does the oocyte cease Meiosis II? does it begin again?

A

3 hours before ovulation

and yes, if fertilized

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

What is leftover once the ovum is released from the Graffian follicle?

A

the corpus luteum

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

What does the corpus luteum do?

A

produces hormones like progesterone to prepare the uterus for implantation

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

What does the corpus luteum become if fertilization doesn’t occur?

A

the corpus albicans

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

What forms the acrosome of the sperm?

A

golgi bodies accumulate

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

What organelle(s) are left in the mature sperm?

A

mitochondria

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

What damages mitochondria in sperm? How far out can these exposures impact pregnancy?

A

oxidative stressors

30-60 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What hormone is required for the production of testosterone?
LH
26
Where does fertiization typically occur?
ampullary region of the uterus
27
What happens to the sperms prior to fertilization?
capacitation -> sheds glycoproteins
28
What happens once the sperm binds to the zona pellucida?
acrosome rxn -> sperm can now make it's way to egg's cell membrane
29
What happens after the sperm breaks down the zona pellucida?
1. it binds to cell membrane 2. cell membrane hardens so no other sperm can bind 3. membranes fuse together and sperm nucleus enters 4. pronuclei fuse together 5. form the diploid zygote
30
What occurs during 0-3wks?
early development cleavage gastrulation
31
What takes place from 4-8wks?
period of embryonic organogenesis
32
What is considered 9-38wks?
fetal period
33
How long after fertilization does the 1st cell division occur?
30-36 hours
34
Meiosis is completed ___________ after the ovum is released.
12-24 hours
35
By day 3 you have the:
morula stage
36
By day 4 you have the:
blastocyst
37
btwn thew morula and early blastocyst the embryo undergoes:
compaction
38
the blastocyst becomes two cell layers, known as _________. when does this happen?
inner cell mass trophoblasts (outside) days 4.5-5
39
What pole does the ICM form on of the embryo?
animal pole
40
What occupies that opposite pole of the ICM?
fluid-filled space that -> endodermal layer and yolk sac
41
Where do ectopic pregnancies occur?
``` abdominal cavity ampullary region of the tube (80%) tubal implantation interstitial implantation implantation in region of the internal os ```
42
How do ectopic pregnancies occur?
- due to invasive nature of trophoblasts | - due to abnormal transport or recognition of blastocysts
43
What are some adverse outcomes of ART?
``` embryo effects spontaneous abortions multiple births adverse perinatal outcomes birth defects DD childhood malignancies longer-term outcomes? ```
44
the inner cell mass is also known as the:
embryoblast
45
What two things are interacting as the 1st week ends?
syncytiotrophblasts and the endometrium
46
What days make up wk 2?
Days 6-15
47
What's the other name for the 2nd week of development?
The week of 2s
48
During the 2nd wk of development, the trophoblast gives rise to ->
cytotrophoblasts syncytiotrophoblasts
49
During the 2nd wk of development, the embryoblast gives rise to ->
hypoblast epiblast
50
During the 2nd wk of development, the extraembryonic mesoderm ->
splits into the somatic (parietal) and splanchic (visceral) layers
51
During the 2nd wk of development, what cavities form?
yolk sac amniotic cavity
52
By what day is the embryo implanted into the endometrium?
Day 7.5
53
What is happening in the syncytiotrophoblasts on day 9? Maternal blood vessels?
lacunae are forming blood vessels are enlarging
54
What is occurring in the syncytiotrophoblasts by day 12?
maternal sinusoids are fusing with lacunae
55
What begins forming by Day 13?
primary villi surrounded by trophoblastic lacunae filled with maternal blood
56
When do the primitive streak and node begin forming?
Day 15
57
In what direction does the primitive streak grow?
caudal to cranial
58
What happens as the primitive streak forms?
cells invaginate and migrate through the primitive streak
59
What happens to the first wave of cells that migrate thru the primitive streak? When does this begin?
they replace the hypoblast cells -> eventually differentiate into endodermal cells Day 16
60
What happens to the cells that migrate through the primitive streak after the 1st wave? When? What do they form?
they fill the resulting space between the yolk sac and epiblast layer -> eventually differentiate into mesoderm cells Day 17 extend cranially from primitive node to form notochordal process
61
the mesoderm that is lateral to the midline in gastrulation becomes ->
paraxial, intermediate, and lateral plate mesoderm
62
By day 18, lateral plate mesoderm has split into what two layers ->
somatic and splanchic mesoderm
63
By day 19, what membranes and plate have formed?
oropharyngeal and cloacal neural plate
64
What has happened by day 20 with the notochordal process?
notochordal process fuses with endoderm to form notochordal plate
65
What happens to the notochordal plate at wk 3->4 (Day 22)?
notochord plate separates from endoderm to form the solid notochord
66
What cells form the lining of the yolk sac (not from germ layer)?
hypoblast cells

Embryology (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions