Brainscape's Knowledge GenomeTM

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


See full index

Histology & Embryology > Lecture 4 - Early Embryogenesis > Flashcards

Lecture 4 - Early Embryogenesis Flashcards

1
Q

when does cleavage of the zygote happen

A

mitotic division happens rapidly at 30 hours after fertilization

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

What day?

12 -32 blastomeres (=morula)
inner cell mass (embryoblast) surrounded by layer of flattened cells (trophoblast)

A

Day 3

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

trophoblast secretes

A

early pregnancy factor

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

What day?

morula is now called blastocyst

blastocystic cavity forms

A

Day 4

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

outer cells that give rise to the embryonic part of the placenta

A

trophoblast

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

cells that form the embryo

A

embryoblast

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

What day?

blastocyst travels in uterine fluid and sheds zona pellucida

A

Day 5-6

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

what day?

blastocyst attaches to endometrial lining
trophoblast differentiates into two layers

A

Day 6

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

trophoblast differentiates into (2)

A

cytotrophoblast - inner layer of cells

synctiotrophoblast - outer layer of cells that extends into endometrial epithelium and allows the blastocyst to “burrow” in

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

synctiotrophoblast secretes

A

Human chorionic gonadotropin (hCG)

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

What happens in week 2? (4 things)

A

blastocyst implants

formation of embryonic disc

formation of amniotic cavity

trophoblast continues to differentiate

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

week 2: embryoblast forms embryonic disc, which consists of (2)

A

epiblast - thicker layer that forms floor by amniotic cavity

hypoblast - thinner layer, continuous with the primordial umbilical vesicle

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

what is the exocoelemic membrane?

A

forms to make the primary umbilical vesicle and surrounds the blastocystic cavity

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

________ cavity is on top of developing embryo and

________ cavity is below

A

amniotic

blastocystic

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

what is the amnion

A

thin, transparent, nonvascular cavity

formed by aminogenic cells, maternal blood, and fetal kidneys

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

functions of amnion (3)

A

protective cushion
temperature
free movement

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

what day?

embryo completely embedded in endometrium
closing plug forms
endometrial wall regenerates, covering the plug

A

Day 10

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

what is the chorion?

A

the outermost membrane surrounding the embryo

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

what do the chorionic villi do?

A

extract nutrients from maternal blood and endometrial tissue

20
Q

when do primary chorionic villi appear?

A

end of week 2

21
Q

What happens in week 3? (3 general things)

A

gastrulation - differentiation of 3 germ layers

development of notochord

Allantois and chorionic villi formation

22
Q

Define:

primitive streak

primitive groove

primitive node

primitive pit

A

streak - cells migrate to dorsal caudal location and elongate by adding more cells

groove - small depression in primitive streak

node - cluster of cells at cranial end of primitive streak

pit - deepest part of primitive groove

23
Q

cells leave the primitive streak to form _____

A

mesenchyme

24
Q

what is a sacrococcygeal teratoma

A

remnants of primitive streak persist

- tumor has tissues from all 3 germ layers at different points of formation

25
Q

Inductions for gastrulation

A

growth factors and signaling from cells, coordinate factors with genes, cell interactions, proliferation of cells, and apoptosis

26
Q

where does notochordal process begin to form?

A

deep to the primitive pit

27
Q

notochordal process (with notochordal canal) extends cranially to _______ ________

A

prechordal plate

28
Q

cellular rod formed from axial mesoderm that creates the axis of the embryo, is a template for development of bones of the head and vertebral column, is site of vertebral bodies, and forms the neural plate

A

notochord

29
Q

define neural plate (general)

A

primordial CNS

30
Q

notochord degenerates and forms the _____

A

nucleus pulposus of IV discs

31
Q

describe development of neural tube (day 18)

A

central axis of neural plate invaginates and forms the neural GROOVE with neural FOLDS.
The FOLDS then fuse together to form the the neural TUBE which separates from the ectoderm

32
Q

what do neural crest cells do

A

separate from the neural tube as it’s developing, and begin to lay framework for PNS

33
Q

name 2 neural tube defects

A

spina bifida

anencephaly

34
Q

what are somites

A

surface elevations in paraxial mesoderm

form axial skeleton, muscle, and some skin

35
Q

transcription factors involved in the development of somites (2)

A

Fox C1 and C2

Delta-Notch

36
Q

The allantois develops from the ________ and is the basis of ___________ and __________

A

umbilical vesicle

early blood formation

urinary bladder

37
Q

main exchange site of material between embryo and maternal blood

A

chorionic villi

38
Q

brings primordium of brain above heart and oropharyngeal membrane

A

head fold

39
Q

brings tail region over cloacal membrane, umbilical cord is brought ventrally

A

tail fold

40
Q

brings edges of embryonic disc ventrally forming a cylindrical embryo

A

lateral fold

41
Q

________ is brought ventrally and fuses with _______ to form umbilical cord

A

connecting stalk

umbilical vesicle

42
Q

when does folding happen? (week)

A

Week 4

43
Q

what appears in week 4? (6)

A 
pharyngeal arches
upper limb buds
lower limb buds
otic pits - future internal ears
lens placodes - future lenses
rudimentary cardiovascular system
44
Q

Highlights of week 5 (2)

A

Growth of head rapidly increases

mesophrenic ridges - future kidneys

45
Q

Highlights of week 6 (3)

A

twitching
digital rays - digits
auricular hillocks - auricle of ear

46
Q

Highlights of week 7 (1)

A

Hand plates - notches separate future digits

47
Q

Highlights of week 8 (6)

A

digits separated, but webbed
eyelids close
hands and feet grow towards each other ventrally
head is disproportionately large
primary ossification centers begin to form
sex differences begin

Histology & Embryology (24 decks)

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