Brainscape's Knowledge GenomeTM

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


See full index

Embryology > Chapter 5 > Flashcards

Chapter 5 Flashcards

1
Q

What genes are expressed by cells in the AVE during the bilaminar disc stage?

A

Genes expressed by AVE cells include OTX2, LIM1, and HESX1

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

Which secreted factors are expressed by AVE cells to establish head formation?

A

AVE cells secrete Cerberus and Lefty, members of the TGF-B family.

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

What is the role of Cerberus and Lefty during early embryonic development?

A

Cerberus and Lefty inhibit nodal activity, establishing the cranial end of the embryo.

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

How do Cerberus and Lefty influence nodal expression?

A

Cerberus and Lefty inhibit nodal expression at the caudal end, allowing nodal activity to continue and establishing the primitive streak.

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

What is the function of the primitive streak?

A

The primitive streak is established and maintained by nodal expression. It is responsible for forming the central axis of the embryo.

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

What happens once the primitive streak is formed?

A

NODAL upregulates genes responsible for dorsal and ventral mesoderm formation, as well as the formation of head and tail structures.

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

How does nodal expression influence mesoderm formation?

A

NODAL upregulates genes involved in dorsal and ventral mesoderm formation

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

Which member of the TGF-B family is involved in the establishment of the cranial end of the embryo?

A

Nodal, a member of the TGF-B family, is inhibited by Cerberus and Lefty to establish the cranial end.

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

What are the consequences of Cerberus and Lefty absence at the caudal end?

A

The absence of Cerberus and Lefty allows nodal expression to continue, leading to the establishment and maintenance of the primitive streak

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

What role does NODAL play in embryonic development?

A

NODAL activates genes responsible for dorsal and ventral mesoderm formation, as well as head and tail structure formation after the primitive streak is established

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

Derived from inner mass of embryo
Can be obtained from embryo after IVF (reproductive
cloning

A

Embryonic stem cells

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

can form any cell or tissue;
■ has potential to cure disease

A

Pluripotent

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

introduction of nuclei to enucleated oocyte

A

Therapeutic cloning or Somatic Nuclear Transfer:

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

restricted in ability to form different cell or
tissue type

A

Adult stem cells: Multipotent

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

Lost within 2-3 weeks of fertilization
○ 50% of pregnancies end in spontaneous abortion
○ PCR can detect genetic defects

A

Abnormal zygotes`

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

Due to the constant erosion of the sinusoids by
the Trophoblast.
Maternal blood begins to flow through the
trophoblastic system

A

Uteroplacental
Circulation

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

Maternal capillaries which are congested and
dilated, maternal blood enters the lacunar system

A

Sinusoids (Maternal
sinusoids)

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

Fine, loose connective tissue that appears
between the Cytotrophoblast and Exocoelomic
cavity.

A

Extraembryonic
Mesoderm

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

The large space or cavity formed by the
extraembryonic mesoderm

A

Extraembryonic Cavity
aka Chorionic Cavity

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

Additional cells that are produced by the
Hypoblast.

A

Secondary Yolk Sac or
Definitive yolk sac

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

The pinch portion of the Secondary yolk sac,
which are found in Extraembryonic coelom or
Chorionic cavity.

A

Exocoelomic Cysts

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

Expansion that forms a large cavity from the
extraembryonic coelom

A

Chorionic cavity

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

Formed from the connecting stalk (the place
where extraembryonic mesoderm transverses
the chorionic cavity)

A

Umbilical Cord

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

where the formation begins
○ A narrow groove with slightly bulging regions on the either
side.
■ cells of the epiblast migrate toward this area
○ Clearly evident at 15-16th day embryo

A

Primitive Streak

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

cephalic end of primitive streak
○ Slightly elevated area surrounding the primitive pit

A

Primitive Node

25
Q

an inward movement of the epiblast towards the primitive
streak then detaches and slips beneath it

A

INVAGINATION

26
Q

It controls the cell migration and specifications
○ Synthesized by the primitive streak

A

FIBROBLAST GROWTH FACTOR 8 (FGF8)

27
Q

controls and down regulating by
FGF8
● A protein that binds the epiblast cells
together

A

E-CADHERIN

28
Q

source of all 3 germ layers

A

Epiblast

29
Q

solid cord of cells formed by endoderm cells; underlies
neural tube and basis for axial skeleton

A

DEFINITIVE NOTOCHORD

30
Q

indentation of epiblast; temporarily
connects amniotic fluid and yolk sac cavities

A

Neurenteric canal

31
Q

formed at caudal end of embryonic disc
○ Consist of endoderm and ectoderm cells; no intervening
mesoderm
○ Similar characteristic with oropharyngeal membrane

A

Cloacal membrane

32
Q

Diverticulum that appear on 16th day

A

alloenteric diverticulum or allantois

33
Q

Occurs BEFORE and AFTER period of gastrulation

A

ESTABLISHMENT OF THE BODY OF AXES

34
Q

Express genes essential for head formation
○ Establishes cranial end of embryo prior to gastrulation

A

Anterior visceral endoderm (AVE)

35
Q

Initiates and maintains primitive streak
○ Upregulates genes responsible for formation of dorsal and
ventral mesoderm; tail and head structures

A

Nodal (member of TGF-beta)

36
Q

Centralizes mesoderm to contribute to kidneys

A

Bone morphogenetic protein 4 (BMP4)

37
Q

“The Organizer”

A

Node

38
Q

Dorsalized into notochord, somite, and somitomeres

A

Cranial mesoderm

39
Q

Maintains node
○ Induces regional specificity in forebrain and midbrain
○ Without this = embryo fail to gastrulate properly; lack
forebrain and midbrain

A

HNF-3B (beta)

40
Q

HNF-3B (beta)

A

Laterality

41
Q

Induces nodal expression

A

FGF 8

42
Q

Homeobox-containing transcription factor
○ Responsible for left sidedness
○ Repeated expression on left side of heart, stomach, gut
○ Organs assume normal asymmetrical body positions

A

PITX2

43
Q

Acts barrier to prevent left-sided signals from crossing
over

A

Lefty

44
Q

Repressor for left sided gene expression on the right
○ Inhibitory

A

Sonic hedgehog (SHH)

45
Q

Establishes laterality
○ Concentrated on left side
○ Broken down by monoamine oxidase (MAO) on right
side
○ Leads to situs inversus and dextrocardia when altered

A

Serotonin (5HT)

46
Q

a transcription factor
○ Restricted to right lateral plate of the mesoderm
○ Regulates genes for establishing right side

A

SNAIL

47
Q

becomes paraxial mesoderm

A

LATERAL EDGES OF THE NODE

47
Q

intermediate mesoderm

A

Midstreak region

48
Q

extraembryonic mesoderm

A

CAUDAL MOST PART OF STREAK

48
Q

lateral plate mesoderm

A

Caudal Part

48
Q

shows regressive changes until it disappears
towards the end of the 4th week.

A

Primitive streak

49
Q

Deficiency of the midline in craniofacial structures
○ May be caused by high doses of alcohol (kills cells in the
anterior midline of the germ disc)
○ small forebrain, 2 lateral ventricles are often merge into
one, eyes are close together (hypotelorism) and closed

A

Holoprosencephaly

49
Q

insufficient mesoderm is formed in the caudal-most region
of the embryo

A

Caudal Dysgenesis (sirenomelia)

50
Q

is caused by mutations in zinc finger
transcription factor ZIC3

A

X-linked
Heterotaxy

50
Q

stage of trophoblast wherein it consists of
cytotrophoblastic core covered by a syncytial layer at the
beginning of 3rd week
○ Mesodermal cells penetrate the core of primary villi and
grow towards the decidua

A

Primary Villi

51
Q

formed when the mesodermal cells penetrate the core of
primary villains grow towards decidua

A

Secondary Villi

52
Q

formed at the end of 3rd week when mesodermal cells in
the core of the villus begin to differentiate into blood cells
and small blood vessels.
○ Capillaries in this villi make contact with capillaries
developing in the mesoderm of the chorionic plate in the
connecting stalk.

A

Tertiary Villi (Definitive Placental Villi)

53
Q

villi extension from chorionic plate to decidua basalis

A

Stem/ Anchoring Villi

54
Q

branch from the sides of stem villi. This is the site for
exchange of nutrients and other factors.

A

Free (Terminal) Villi

55
Q

attaches the embryo to its trophoblastic shell and later on
develops into umbilical cord.

A

Connecting Stalk

Embryology (6 decks)

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