Embryology (fertilisation, week 1 -2)

Question 1

How many sperm are allowed to penetrate the ovum

Answer 1

one

Question 2

What is the products of oogensesis meiosis

Answer 2

1 ovum and 3 polar podies (X)

Question 3

What is the product of spermogeneis meiosis

Answer 3

4 sperm bodies ( X/Y)

Question 4

What is the first cell of the body

Answer 4

zygote

Question 5

What fuses between the egg and the sperm

Answer 5

The pronucleases

Question 6

What enters the ovum when the sperms pronucleus fuses

Answer 6

the sperms genetic material, everything else is left behind

Question 7

Is mitochondiral cell organelles inherited by the paternal or maternal

Answer 7

Maternal

Question 8

what is an example of a maternal mitochondrial inherited condition

Answer 8

Lebers hereditary optic neuropathy - blindness

Question 9

What are the two processes that occur in week 1

Answer 9

The zygote divides to from a blastocyte

The zygote moves through the uterine tubes to the uterine cavity

Question 10

The zygote divides by mitotsis forming a ball of cells called what?

Answer 10

morula

Question 11

The central core of the mass of cells becomes harder forming a cavity through, what is this cavity called

Answer 11

blastolytic cavity

Question 12

What is the cells that from the outer layer of the morula called

Answer 12

trophoblast

Question 13

Where is the inner cell mass found in the morula

Answer 13

The cells that are accumulating at one end of the cell

Question 14

The ovary releases the ovum and fertilisation occurs in the uterine tubes, what feature of the uterine tubes than allows the transport of the zygote to the uterine cavity

Answer 14

They have cillated epithelium to push zygote through uterine tube and into uterine cavity

Question 15

When and where should the blastocyte be formed by

Answer 15

around 5-6 days when it reaches the uterine cavity

Question 16

How long is the first division of the zygote to from the balstocyte

Answer 16

36 hours

Question 17

What happens to the division time as it continues moving through the uterine tubes

Answer 17

Successful division take less time

Question 18

What should the blastocyte be ready to do when it reaches the uterine cavity

Answer 18

ready for implantation

Question 19

What hormones prepare the body form implantation

Answer 19

Progesterone and oestrogen produced by the ovary

Question 20

Due to what circumstance can ectopic pregnancy occur

Answer 20

cilia function is abnormal, so zygote implants in the uterine tubes rather than the uterine cavity, leading to a failure in the pregnancy as the uterine tube cant support it

Question 21

What is the differences between monozygotic and dizygotic twins

Answer 21

mono = 1 zygote, share placenta, genetically identical 
Di = 2 zygotes, different placentas, not genetically identical

Question 22

Where does implantation occur in the uterine cavity

Answer 22

in the endometrium layer

Question 23

By what day does the blastocyte burrow into the endomtetium

Answer 23

day 7

Question 24

The trophoblast divides to from 2 layers called what

Answer 24

Chrorion

Question 25

What does the chorion chronic villi allow the trophoblast to do

Answer 25

Helps the implantation into the endometrium

Question 26

What does the chronic vili of the trophoblast then go on to become for the embryo

Answer 26

the placenta

Question 27

What is the part of the endometrium called which hold the burrowed blastocyte

Answer 27

Decidua

Question 28

When the blastocyes implants in the endometrium these is an increase in blood vessels surrounding the chorion what are these blood vessels called

Answer 28

decidua basalis

Question 29

What hormone does the chorion secrete and what is its function

Answer 29

secretes hormone human chorionic gonadotrophin HCG prevents endometrium sheding by infoming ovary to keep producing oestrogen and progesterone

Question 30

What hormone is used to detect pregnancy

Answer 30

HCG

Question 31

HCG levels increase until what week

Answer 31

12 weeks gestation

Question 32

Are the chorion villi in contact with the maternal blood?

Answer 32

No, passage of nutrients occurs by diffusion

Question 33

What is the main functions of the placenta

Answer 33

Foetal nourishment inspirit of waste and gas immune protection

Question 34

How long does it take the placenta to mature

Answer 34

18 - 20 weeks

Question 35

Where is the two surfaces of the placenta facing and what are they like?

Answer 35

maternal - desidua basalis (rough) | foetus - amniotic membrane attaching to the end of umbilicus chord (smooth)

Question 36

What does the inner cell mass go on to from

Answer 36

Bilaminar disc

Question 37

What two layers are divided by the bilaminar disc

Answer 37

the epiblast and the hypoblast

Question 38

What cavity sits above the epiblast

Answer 38

the amniotic cavity (where the embryo develops)

Question 39

What cavity sits below the hypoblast

Answer 39

Yolk sac