Histology - Pre-Embryonic - Reverse Flashcards Preview

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Flashcards in Histology - Pre-Embryonic - Reverse Deck (70)
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1
Q

mitotic divisions that form cells called blastomeres

A

Cleavage

2
Q

tighter blastomere intercellular adhesion forms morula, results in the formation of an inner and outer cell mass.

A

Compaction

3
Q

uterine fluid pumped into morula forms blastocyst

A

Cavitation

4
Q

blastocyst hatches from the zona pellucida

A

Hatching

5
Q

blastocyst implants in endometrium of uterine wall

A

Implantation

6
Q

Mitotic nondisjunction during cleavage, generally less severe; e.g., mosaic Down syndrome

A

mosaicism

7
Q

gives rise to the embryo (inner cell mass)

A

embryoblast

8
Q

gives rise to the fetal placenta (outer cell mass). cytotrophoblast, syncytiotrophoblast, vascular lacunae

A

trophoblast

9
Q

end with embryoblast

A

Embryonic pole

10
Q

end opposite embryoblast

A

Abembryonic pole

11
Q

blastocyst hatches from zona pellucida (ZP prevents implantation)

A

Hatching

12
Q

trophoblast at embryonic pole invades the endometrium on DAY 6

A

Implantation

13
Q
  1. Implantation completed: uteroplacental circulation is established 2. Bilaminar disc formed: embryoblast differentiates into 2-layered disc
A

Week 2: Events

14
Q
  1. cytotrophoblast 2. syncytiotrophoblast (part of chorion)
A

trophoblast becomes:

15
Q
  1. epiblast 2. hypoblast (form the fetus, amnion, and part of chorion)
A

Embryoblast becomes:

16
Q

mitotic cells that give rise to the syncytiotrophoblast.

A

Cytotrophoblast

17
Q

the epithelial covering of the highly vascular embryonic placental villi, which invades the wall of the uterus to establish nutrient circulation between the embryo and the mother. It forms the syncytium that erodes endometrium and its vessels.

A

Syncytiotrophoblast

18
Q

maternal blood

A

vascular lacunae

19
Q

nutrition from maternal blood 1. uteroplacental circulation 2. implantation bleeding

A

nutrition from uterine gland secretions give way to

20
Q

human chorionic gonadotropin (hCG) that maintains progesterone secretion in the ovaries to promote uterine blood flow that sustains embryonic and fetal growth. Linked to emesis gravidarum (morning sickness).

A

Syncytiotrophoblast secretes

21
Q

hCG serum level elevation at day 8

A

Pregagncy test dectects

22
Q

implantation outside of the uterine body, most commonly in the unterine tube - “tubal pregnancy” - 95%+ of ectopic prenancies in uterine tube.

A

Ectopic pregnancy

23
Q

implantation over or near the cervical opening (internal os), usually presents late in pregnancy

A

Placenta previa

24
Q

trophoblast implants, but embryoblast is absent/incomplete. May produce a benign tumor called a hydatidiform mole. Elevated hCG secretion.

A

Molar pregnancy

25
Q

malignant tumor of the trophoblast. Elevated hCG secretion.

A

Choriocarcinoma

26
Q

one of the membranes that exist during pregnancy between the developing fetus and mother, formed by extraembryonic mesoderm and the two layers of trophoblast and surrounds the embryo and other membranes. Chorionic villi emerge from the chorion, invade the endometrium, and allow transfer of nutrients from maternal blood to fetal blood.

A

Chorion

27
Q

the inner layer of the trophoblast. It is interior to the syncytiotrophoblast and external to the wall of the blastocyst in a developing embryo.

A

cytotrophoblast

28
Q

embryoblast undergoes lamination to form two layers, hypoblast and epiblast

A

Bilaminar disc

29
Q

cells divide/migrate to line the blastocyst cavity. blastocyst cavity becomes the primary (primitive) yolk sac.

A

Hypoblast

30
Q

a tissue type derived from the inner cell mass of the blastocyst. It lies above the hypoblast, and undergoes cavitation whereby the amniotic cavity (AC) is formed. It differentiates to form all three layers of the trilaminar germ disc (ectoderm, mesoderm, and endoderm) during gastrulation.

A

epiblast

31
Q

a short lived combination of hypoblast cells and extracellular matrix. At day 9-10 of embryonic development, cells from the hypoblast begin to migrate to the embryonic

A

exocoelomic membrane

32
Q

forms adjacent to the hypoblast, and spaces appear in it which unit to form the large chorionic cavity (CC).

A

Extraembryonic mesoderm (EM)

33
Q

“pinched off” from the pYS (primary yolk sac)

A

secondary (definitive) yolk sac (sYS)

34
Q

hypoblast cells which have migrated to line the blastocyst cavity. It later becomes secondary yolk sac after part of it is pinched off. Thereafter its remnants degenerates.

A

Primary yolk sac

35
Q

Zygote formed after fertilization in ampulla of uterine tube

A

Day 1

36
Q

Morula enters uterus

A

Day 4

37
Q

Implantation of blastocyst begins

A

Day 6

38
Q

Positive pregnancy test, detectable hCG levels.

A

Day 8

39
Q
  1. Implantation completed (uteroplacental circulation established) 2. Bilaminar disc formed (hypoblast & epiblast appear).
A

End of Week 2

40
Q

Extraembryonic mesoderm + cytotrophoblast + syncytiotrophoblast

A

chorion =

41
Q

blastocyst cavity, embryoblast, trophoblast, embryonic/abembryonic poles

A

Blastocyst

42
Q

gastrulation, neuralation, body folding

A

Week 3 Events

43
Q

Loosely arranged, migratory. formed via epithelial-mesenchymal transformation at the primitive streak & node

A

mesenchymal cells

44
Q

sites of epiblast invagination. regress & degenerate at the end of week 4 when gastrulation completes.

A

Primitive streak and node

45
Q

head-tail axis

A

Cephalocaudal

46
Q

front-back axis

A

Ventral-dorsal

47
Q

Cephalocaudal, Ventral-dorsal, left-right

A

body axes

48
Q

future mouth

A

oropharyngeal membrane

49
Q

future anus

A

cloacal membrane

50
Q

structure which includes the transformation of the neural plate into the neural tube. induces formation of neural tube (future brain, spinal cord)

A

Neurulation

51
Q

failure of rostral neuropore to close

A

Anencephaly

52
Q

failure of caudal neuropore to close

A

Spina bifida

53
Q

Forms gut tube from endoderm and mesoderm around the secondary yolk sac. Also forms intraembryonic cavity.

A

Lateral body folding

54
Q

becomes thoracic and abdominopelvic cavities, froms during lateral body folding

A

intraembryonic cavity

55
Q

Relocates primitive mouth and heart to adult position, is driven by longitudinal growth of the neural tube

A

Cephalocaudal body folding

56
Q

helps the embryo exchange gases and handle liquid waste.

A

Allantois

57
Q

Tail regresses, limbs elongate & rotate, digits appear; face develops. Organogenesis. Greatest risk of birth defects in week 5.

A

Week 4 to 8

58
Q

gametes and epithelial cells lining digestive organs, respiratory airways, and some urogenital passages.

A

Endoderm

59
Q

epidermis & its derivatives (hair, nails, glands)

A

Surface Ectoderm

60
Q

neural tube gives rise to the brain and spinal cord.

A

Neuroectoderm

61
Q

differentiates into somites (somitomeres in head region), becomes dermis, skeletal muscle, vertebrae & ribs. lateral to (at the side of) the neural tube.

A

Paraxial Mesoderm

62
Q

urogenital system (majority)

A

Intermediate mesoderm

63
Q

CT of body wall & limbs

A

Lateral plate mesoderm (parietal layer)

64
Q

GI/respiratory organs (excelpt epithelial lining)

A

Lateral plate mesoderm (visceral layer)

65
Q

fluid rich ECM with multipotent mesenchymal cells

A

Mesenchyme

66
Q

bilaterally paired blocks of paraxial mesoderm that form along the anterior-posterior axis of the developing embryo. They give rise to sclerotome, myotome, dermatome for each body segment.

A

Somites

67
Q

cleveage, compaction, morula formed, cavitation, blastocyst formed, zona pellucida hatching, implantation initiated

A

Week 1 Cellular Events

68
Q

axial skeleton

A

sclerotome

69
Q

dermis

A

dermatome

70
Q

skeletal muscle

A

myotome