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Flashcards in 510-2 Deck (45)
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0
Q

When does fetal development occur?

A

9-38 weeks

1
Q

How long is embryonic development?

A

8 weeks

2
Q

What is the ampulla?

A

Region of the Fallopian tube where fertilization occurs (12-24hrs)

3
Q

What is ovulation?

A

When an oocyte is released from an ovary and swept into the Fallopian tube by ciliated epithelia. Each ovary ovulates every other month.

4
Q

What is follicle stimulating hormone (FSH)?

A

Stimulated the follicle to grow. This hormone is often used to treat women with infertility issues because it stimulates the growth and production of multiple oocytes.

5
Q

What is the corona radiata?

A

The first layer of protection that a sperm must break through.

6
Q

What is the zona pellucida?

A

The second layer the sperm must break through. This layer is like an shell composed of glycoproteins.

7
Q

What is the acrosome?

A

Vesicle in the tip of the sperm that has digestive enzymes used to break down the zona pellucida (acrosome reaction)

8
Q

What is polyspermy?

A

When more than one sperm fertilizes an egg. This results in zygot death because of the mismatched chromosomes (69).

9
Q

What are the 3 stages of oocyte penetration?

A

Stage 1: sperm penetrates corona radiata
Stage 2: acrosome reaction as sperm breaks through zona pellucida
Stage 3: sperm breaks through oocyte membrane and loses its own membrane triggering the zona reaction

10
Q

What is the zona reaction?

A

When a sperm penetrates the oocyte membrane a calcium mediated change in the zona pellucida prevents other sperm from fertilizing the egg.

11
Q

What is a zygote?

A

A fertilized egg (12-24 hrs)

12
Q

What is pluripotency?

A

Early stage cells can differentiate into a variety of things but lose the potential to differentiate with each cell division because the environment changes (especially after compaction during the 8 to 16 cell transition)

13
Q

What is a blastomere?

A

A cell in the 2, 4, 8, or 16 cell zygote

14
Q

What is a morula?

A

Solid ball of blastomeres. Forms around the 4th day when the zygote is entering the uterus.

15
Q

What is compaction?

A

Occurs during the 8 to 16 cell transition when cells make tight and gap junctions.

16
Q

What is paracrine?

A

Substance produced by one cell that affects another cell (endocrine= paracrine that travels in the blood)

17
Q

What is autocrine?

A

Substance produced by a cell that affects itself

18
Q

What is a blastocyst?

A

A blastocyst draws fluid into its blastocele and two layers of cells result: trophoblast and embryoblast. This occurs around 4.5 days.

19
Q

What is an embryoblast?

A

Layer in the blastocyst that will give rise to the embryo

20
Q

What is the trophoblast?

A

Outside layer of the blastocyst that will give rise to the placenta

21
Q

What are the 3 layers of the uterus?

A
  1. ) perimetrium- thin outer membrane
  2. ) myometrium- muscular middle layer
  3. ) endometrium- vascular middle layer with mucous glands
22
Q

What is implantation?

A

Growth of the trophoblast into the endometrium (penetrates basement membrane). Usually happens around 6th day

23
Q

What is the syncytiotrophoblast?

A

Outer layer of the trophoblast with vague cell boarders to aid in blood transfer between mother and fetus

24
Q

What is the cytotrophoblast?

A

Inner layer of trophoblast composed of large single cells

25
Q

What are the two layers of the embryoblast?

A

Epiblast (will form the embryo) and Hypoblast (will form the yolk sac)

26
Q

What is the extra embryonic coelom?

A

Cavity between the hypoblast and trophoblast that takes in fluid to push yolk sac and trophoblast away from eachother and allows for the chorion to develop

27
Q

What is the chorion?

A

Produces human chorionic gonadotropin (hCG) which keeps the corpus luteum alive and producing progesterone and estrogen to keep the uterus pregnant (used in pregnancy detection)

28
Q

What is gastrulation?

A

Process of the development of 3 germ layers: ectoderm, mesoderm, and endoderm. Takes place from day 13-19.

29
Q

What does ectoderm give rise to?

A

Skin, mouth lining, enamel, nervous system

30
Q

What does mesoderm give rise to?

A

Muscle, bone, blood, lymphatic system, spleen, lungs, heart, reproductive system, and excretory system

31
Q

What does endoderm give rise to?

A

Lining of the gut, liver, pancreas, bladder, thyroid, parathyroid, and lungs

32
Q

What is mesenchyme?

A

Undifferentiated connective tissue

33
Q

What is the primitive streak?

A

Extends from the primitive node caudally. Is controlled by the gene nodal. The primitive node cells produces transforming growth factor B and bone morphogenic protein 4 that stimulate mesoderm growth.

34
Q

What is Fibroblast Growth Factor 8?

A

Transcription factor that controls the inward migration of cells during gastrulation

35
Q

What are chordin and noggin?

A

They are expressed by the primitive node and direct differentiation of the mesoderm into the notochord and somites. Play an important role in establishing anterioposterior axes.

36
Q

What did the Hans Spemann experiment show us?

A

Transplanting the dorsal lip of a blastopore onto another embryo organizes the growth of another head

37
Q

What is goosecoid?

A

Transciption factor that stimulates chordin to signal for the production of cranial mesoderm. If over expressed can lead to two heads.

38
Q

What is the notochord?

A

Created by cells migrating anteriorly from the primitive node. has inductive effects on surrounding tissues.

39
Q

What is neurulation?

A

Take place around the 3rd week. Its when the notochord signals the ectoderm to thicken and become neural ectoderm. This neural plate develops a flap and grooves that eventually fold on itself and create a neural tube (CNS)

40
Q

What are somites?

A

paired mesoderm on either side of the neural tube that develops into dermis, muscle, tendon, and bone.

41
Q

What is spina bifida?

A

When the sacral region of the neural tube doesn’t close properly

42
Q

What is anencephaly?

A

When the cephalic region of the neural tube doesn’t close properly

43
Q

What is neural crest?

A

Cells that originate from the ectoderm but are important in a variety of things including formation of dentin and facial cartilage (ex. abnormal NC migration can lead to Treacher Collins Syndroms)

44
Q

When is the embryo most susceptible to teratogens?

A

3-8 weeks when most organ systems are being established