BL12 - Embryology

Question 1

Name the unspecialised cell that creates sperm?

Answer 1

Spermatogonium

Question 2

Explain the differentiation process of sperm cells

Answer 2

Spermatogonium -MITOSIS- Primary spermatocytes - MEIOSIS 1- secondary spermacytes -MEIOSIS 2- spermatids

Question 3

Explain the differentiation process of egg cells

Answer 3

oogonium - primary oocyte - secondary oocyte - ovum + 3 polar bodies

Question 4

Name the unspecialised cell that creates sperm?

Answer 4

oogonium

Question 5

In females when does meiosis one occur for primary oocytes?

Answer 5

Puberty

Question 6

In females when does meiosis 2 occur for secondary oocytes?

Answer 6

Apon the entry of the sperm

Question 7

Where are the ova formed?

Answer 7

Ovaries

Question 8

What part of the female reproductive organ are the released into?

Answer 8

Ampulla of the fallopian tube

Question 9

What is the cervix

Answer 9

Tight circular muscle that sits between the vagina and the uterus

Question 10

How long do sperm live for?

Answer 10

5 days

Question 11

How long do secondary oocytes live for?

Answer 11

12-24hrs

Question 12

What are the two layers a sperm must get through to get to the egg?

Answer 12

Corona Radiata

Zona Pelucida

Question 13

What is the embryonic age?

Answer 13

Time since fertiliasation

Question 14

What is the gestational age?

Answer 14

Time since last period

Question 15

What is the embryonic period?

Answer 15

3-8 weeks

Question 16

What is the foetal period?

Answer 16

9-38 weeks

Question 17

In IVF what stage is the zygote at when it is implanted?

Answer 17

Blastocyst

Question 18

What is the process called when the zona pellucida is lost?

Answer 18

Hatching

Question 19

Fertilisation =
Day 4
Day 5

Answer 19

Zygote
Morula
Blastocyst (inner and outcell mass)

Question 20

What does trophoblast mean?

Answer 20

FOOD BUD

Outer cell mass in a blastocyst

Question 21

Where is a normal implantation?

Answer 21

Superior and posterior

Question 22

What day is implantation day?

Answer 22

6th Day

Question 23

What is an ectopic pregnancy?

Answer 23

When the blastocyst doesn’t implant in the uterus

Question 24

What is placenta previa?

Answer 24

Implantation occurs at the bottom of the uterus so the birthing canal will be blocked. Can cause haemorrhage on birth so caesarean sections used

Question 25

What occurs in week 2 to the Inner mass cell ?

Answer 25

Inner mass cell divide into Epiblast | Hypoblast

Question 26

What occurs in week 2 to the Trophoblast?

Answer 26

Divides and forms Cytotrophoblast synctiotropoblasts

Question 27

What cavities forms in week 2? and where do they come from?

Answer 27

Hypoblast forms Yolk sack Chorionic cavity

Question 28

What does the Yolk sack form from?

Answer 28

Hypoblast

Question 29

What does the epiblast form?

Answer 29

Amniotic cavity

Question 30

What is gastrulation?

Answer 30

Establishment of 3 germ layers

Question 31

Name the key events of embryology. 6

Answer 31

1) Fertilisation Wk1 2) Implantation Wk2 3) Gastrulation Wk3 4) Neurulation 5) Segmentation 6) Folding

Question 32

What feature appears on the epiblast of at the end of the second week?

Answer 32

Primitive streak and primitive node

Question 33

How does a bilayer become a trilayer?

Answer 33

Epiblast and Hypoblast | Hypoblast is displaced by new cells that form the mesoderm

Question 34

What does the ectoderm form?

Answer 34

Epidermis and Neural Crest (later NS)

Question 35

What does the mesoderm form? and then give 4 examples

Answer 35

Somites muscle; the cartilage of the ribs and vertebrae; the dermis, the notochord, blood and blood vessels, bone, and connective tissue.

Question 36

What does the endoderm form?

Answer 36

endoderm gives rise to the epithelium of the digestive system and respiratory system, and organs associated with the digestive system, such as the liver and pancreas

Question 37

What to the two gaps in the mesosome form?

Answer 37

Mouth and Anus

Question 38

What is Situs inversus?

Answer 38

Condition where organs are reversed

Question 39

When does the new human become bilaterally symmetrical?

Answer 39

End of week 2. | Prior to gastrulation

Question 40

What is the notochord formed from?

Answer 40

Mesoderm

Question 41

What is the notochords role in Neuralation?

Answer 41

signalling role Notochord directs conversion of overlying ectoderm to NEURECTODERM

Question 42

What happens to the mesoderm in neurulation?

Answer 42

splanchnic mesoderm somatic mesoderm intraembryonic coelom Organisation of paraxial mesoderm into segments

Question 43

What is neurulation?

Answer 43

Folding of the neural plate into neural tube

Question 44

What is a somite?

Answer 44

Somites block of mesoderm cells arranged around a small cavity

Question 45

What two things happen is segmentation?

Answer 45

gives rise to repeating structures (ribs, vertebrae, spinal cord segments) Guides innervation

Question 46

How many somites?

Answer 46

31

Question 47

Into which tissue does the blastocyst implant normally?

Answer 47

Uterine lining

Question 48

At which developmental stage does implantation normally occur?

Answer 48

Blastocyst

Question 49

From which embryonic tissue are the three germ layers (and consequently all of the tissues of the body) derived?

Answer 49

Epiblast

Question 50

Initial development of which system of the body is | driven directly by the notochord?

Answer 50

Central nervous system

Question 51

Which tissue lines the intraembryonic coelom (body cavity)?

Answer 51

Mesoderm

Question 52

The notochord forms the nucleus pulposus of | intervertebral disk.. T/F?

Answer 52

True

Question 53

Which part of the mother immune system is dampened during pregnancy?

Answer 53

Cell mediated Response