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Flashcards in Anderson Review Qns Deck (55)
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31

The proatlas anlage contributes to the formation of which structures?

fuses with 3 upper occipital sclerotomes to form the OCCIPITAL BONE

32

What factor is antagonistic to BMP and, when down regulated, allows sutures to fuse?

Noggin

33

what structure is/are derived from the trophoblast?

placenta and chorion
-forms outer layer of blastocyst

34

List/describe factors/conditions that facilitate the exchange of oxygen between the fetal and maternal blood.

Bohr effect--- fetal blood can carry greater quantity of Oxygen than maternal blood for given blood P02--> delivers increased O2 to the tissues

Double Bohr effect---double shift in maternal blood and fetal blood


fetal blood hemoglobin concentration is about 50% greater than maternal

fetal hemoglobin has a higher affinity for O2

35

What factor is in the permanent cartilage pathway that causes chondroblasts to secrete collagen II and cartilage matrix and is continually expressed in permanent cartilage?

sox 9

36

What is/are the effects of HCG on the corpus luteum?

-prevents involution of corpus luteum (CL)
-causes CL to increase secretion of progesterone and estrogens
-causes increased growth in CL

37

What cells can be considered immigrant with regard to the development of integument?

1. melanoblasts--from neural crest
2. Langerhan's cells--from bone marrow
3. Merkel cells--from neural crest

38

Describe the characteristics of satellite cells in reference to muscle tissue differentiation

-able to fuse with muscle fiber and provide growth
-cannot form new muscle fibers
-fxn as stem cells
-give rise to myogenic precursor cells---replace damaged muscle by proliferating, fusing, and differentiating into skeletal muscle fibers

39

What signaling molecules are expressed by the isthmic organizer?

mostly FGF-8, Wnt-1, En-1, En-2

40

What germ layers make up each of the extraembryonic membranes?

amnion--inner cell mass: epiblast derivative
yolk sac-inner cell mass: hypoblast derivative
allantois-inner cell mass; interfaces with placenta via umbilical cord
chorion--part of fetal maternal interface

41

What germ layer is absent from the oropharyngeal membrane?

-lack of mesoderm-->result in perforation of these plates

42

List the characteristics of the early placenta and relate to the late placenta

Early--thick, low permeability, small SA, total diffusion conductance is minuscule

Late--thin, high permeability, large SA, large increase in placental diffusion

43

Name the factors that is/are involved in the formation of rhombomeres 3 and 5

Krox-20

44

Describe the 3 circulatory arcs and their components in the 4-week embryo

vitelline arc-vitelline vessels
allantoic arc---allantoic (umbilical) vessels
embryonic arc--dorsal aorta, aortic arches, anterior cardinal vein, common cardinal vein, posterior cardinal vein, atrium, ventricle, ventral aorta

45

What transcription factor suppresses the formation of anterior gut structures and promotes hindgut development?

Cdx-2

46

At what time during pregnancy does maximum secretion of HCG occur?

10th-12th week of pregnancy

47

What role does p63 play in the formation of the intermediate layer of the epidermis and what is its relation to miR-203?

p63 initiates 3-layered epidermis-forms )basal germinative layer) and superficial peridermal layer

miR-203---inactivates p63 which allows intermediate layer to form

48

What is fillagrin and what is it specifically associated with?

Fillagrin---> filament associated protein that binds to keratin fibers in epithelial cells
--it interconnects the stratum granulosum of intermediate layer of the epidermis

49

Compare permissive and instructive induction and give examples.

permissive induction---responding tissue has all the potentials that are to be expressed, and need only an environment that allows the expression of the traits
ex. fibronectin/laminin does not alter the type of cell that is to be produced, but only enables what has been determined to be expressed

instructive induction----> signal from inducing cell necessary for initiating new gene expression in the responding cell- need for differentiating
ex. optic vesicle places under region of ectoderm causing region of ectoderm to from a lens

50

Which intramembranous bone in the body is the first to become ossified?

the clavicle

51

Prechordal (hypophyseal) cartilages contribute to the formation of which components of the embryonic skull?

basisphenoid bone

52

List characteristicss of early cardiac muscle cells

-does not express Myo D
-contract early
-maintains their ability to divide partially disassembling their contractile apparatus prior to cell division

53

Parachordal cartilages contribute to the formation of which components of the embryonic skull?

basioccipital portion of chondrocranium

54

What skull structures are derived from the membranous portion of the viscerocranium?

-part of the temporal -palatine
-zygomatic -vomer
-maxillary -pterygoid plates, mandible
- nasal - lacrimal
-tympanic ring

55

Name the four components of the typical embryonic pharyngeal arch

1. skeletal element
2. muscles
3. branch of specific cranial nerve
4. artery