Embryo 1- Macus

Front 1

The period of time from fertilization to death is called

Back 1

Ontogeny( life cycle)

Front 2

Ontogeny is divided into two namely

Back 2

1. Prenatal period/development

2. Postnatal period/development

Front 3

The study of Embryology is focused on the prenatal period which studies________?

Back 3

The developmental changes that occur in a developing human from fertilization to delivery.

Front 4

What is fertilization and where does it occur?

Back 4

It is the process of union between the genetic materials of both male and female gametes to form a zygote. It occurs in the ampullae of one of the fallopian tubes.

Front 5

Describe the morula

Back 5

1.It is a stage of cleavage which occurs from 2-4 days.( Or on day 3)

2.It consist of 16- 32 blastomeres

Front 6

Daughter cells of the zygote, within the enclosure of the zona Pellucida are called _______?

Back 6

Blastomeres

Front 7

What is compaction and when does it occur?

Back 7

It a phenomenon whereby blastomeres are held together by tight junctions to form a compact ball of cells.It occurs after the 3rd cleavage( 8 cell stage).

Front 8

A morula has both inner cell mass and outer cell mass. T/F

Back 8

T

Front 9

A blastocyst is formed when fluid penetrates the ___________ into the __________ of the inner cell mass. Forming a fluid filled cavity called ________.

At this stage the inner cell mass will now be called_________ while the outer cell mass will be called__________.

Back 9

Zona Pellucida

Intercellular spaces

Blastocele

Embryoblast

Trophoblast

Front 10

Underthe influence of ____________ , early blastocyst stage embryoblast differentiates into_________&__________.

Back 10

Fibroblast growth factors( FGF)

Epiblast (Dorsally) ED

Hypoblast( ventrally)

Front 11

Blastula is formed _______ days after fertilization.

Back 11

4-6

Hint 11

S-U

Front 12

Abnormal gametes are formed due to failure of separation of homologous chromosomes at which stage?

Back 12

Anaphase I

Front 13

What is crossing over?

Back 13

It is the exchange of homologous chromosomes' segments.

Front 14

Crossover ensures?

Back 14

New combination of genes / redistributes or recombines genes

Front 15

Gamete formation in males are____ while they are _____in females

Back 15

Continuous

Cyclic

Front 16

What is the ovarian cycle?

Back 16

Regular monthly changes that occurs in the ovary of females. It begins at puberty and ends at menopause.

Front 17

The ovulation cycle is in _____ phases, namely:

Back 17

3

•Maturation of follicle

•Ovulation

•Post ovulation follicular changes

Front 18

When a follicle becomes atretic, the surrounding follicular cells along with the oocyte degenerates and is replaced by connective tissue called?

Back 18

Corpus atreticum

Front 19

FSH stimulates maturation of primordial follicle into primary follicle. T/F

Back 19

F

•FSH +GDF9 rescues only about 15-20 of the already formed primary follicles, allowing them to develop further into secondary follicles while the rest degenerates and becomes atretic.

Front 20

In early primary follicles, the follicular cells differentiate into _________?

While in late primary follicles the follicular cells becomes______?

Back 20

•Unilaminar cuboidal cells

•Multilaminar cuboidal cells now called granulosa cells.

Front 21

The primary follicular stage is ended with the formation of the _______, a gel like layer of glycoprotein rich in_____. And also the surrounding stroma cells form the _______

Back 21

•Zona Pellucida

•GAGs

•Theca folliculi( theca interna and externa)

Front 22

Primordial follicles have their development arrested at______ stage, by the help of _____ until puberty after the release of____.

Back 22

•Meiotic prophase I stage

• OMI oocyte maturation inhibitor.

•LH.

Front 23

In secondary follicular stage, a cavity is formed in between the granulosa cells called _____, also the part of granulosa cells surrounding the oocyte are differentiated to form _______. CR(___________)is also developed.

Back 23

•Antrum

•cumulus ophorus

•corona radiata

Front 24

LH has three important effects in ovulation.

Mention the 3 important effects

Back 24

1. It causes an elevation in the concentration of maturation promoting factors which allows oocytes to complete meiosis I and begin II.

2. Luteinization - which is the production of progesterone from stroma cells in ovaries.

3. Follicular rupture.

Front 25

Describe the mechanism of follicular rupture?

Back 25

1. Local bulge appears at an area on the ovary

2. Avascular spot also called stigma appears at the tip of that bulge

3. Collagenase begins to digest the collagen fibers of the surrounding follicle.

4. Prostaglandins causes local muscular contractions in the ovary, forcing out the oocyte.

Front 26

Some of the cumulus ophorus rearrange themselves to around the ________ to form_______.

Back 26

Zona Pellucida

Corona radiata

Front 27

Corpus luteum is formed after release of oocytes. If fertilization occur it becomes

_________ which continues to secrete________ until end of __ month since the role is taken over by the__________. Whereas, if fertilization doesn't occur it becomes________.

Back 27

•Corpus luteum graviditatis

•Progesterone

•4th

•trophoblastic component of the placenta.

•Corpus Albicans

Front 28

During coitus, spermatozoa is deposited at the ___________ of the vagina.

Back 28

•Posterior Fornix

Front 29

Only about ____of spermatozoa enters into the cervix.

They move as a result of __________________ and very little by their own_______

Back 29

• 1%

•Muscular contractions occuring in the uterus and uterine/fallopian tube.

•Propulsion

Front 30

Spermatozoa are unable to fertilize eggs until after undergoing two processes to ensure their viability.

Back 30

• Capacitation

• Acrosome reaction

Front 31

Oocytes are directed via ________, through the contraction or sweeping action of the _______ into the ______ of the uterine tube. Then gets to the ampulla in ___mins via the _________ of the oviduct wall.

Back 31

•Follicular fluid

•Fibriae

•Lumen of the Infundibulum.

•25

•waves of peristalsis of muscle cells

Front 32

Define capacitation

Back 32

It is a conditioning period spanning about 7hrs and involves the removal of

•glycoprotein coat

•seminal plasma protein.

From the plasma membrane that overlies the acrosomal region.

It is initiated by substances secreted by uterus and uterine tube.

Front 33

Capacitation causes some morphological changes to the spermatozoa. T/F

Back 33

F

Front 34

Acrosome reaction is a process induced by______?

Back 34

•Penetration of the corona radiata

Front 35

Acrosome reaction Involves morphological modifications( structural alterations) by ___________of the ___________ with the __________. Followed by the rupture of the fused membranes which produces several/multiple pores through which enzymes such as(_____,_____,_____)(3) from the acrosome can escape.

Back 35

•multiple points fusion

• plasma membrane

• outer membrane of the acrosome

•Hyaluronidase, trypsin-like enzymes, acrosin.

Front 36

There are five phases of fertilization which includes:

Back 36

1. Penetration of corona radiata

2. Penetration of the zona Pellucida

3. Fusion of the male and female gametes

4. Constitution of the male pronuclei

5. Fusion of the nuclei

Front 37

Cleavage takes place partly in (location and time) ____&____.

Back 37

•Uterine tube ( first 3 days)

• Uterus( day 4 -6 )

Front 38

Implantation begins on day_____ and ends on day______

Back 38

7

13

Front 39

On the ___ day fluid passes in from the uterine cavity through the ________ into the cell to form a single fluid filled space called_________. The resulting cell could then be called a _____.

Back 39

•4th

•Zona Pellucida

•Blastocystic cavity/ blastocoele

• blastocyst/ blastula.

Front 40

The process of implantation occurs in five stages:

Back 40

1. Attachment of the blastocyst (via L-selectin) to the endometrium epithelium which contain receptors.

2. Penetration/ invasion of the endometrium by action of enzymes like Integrin, Laminin, Fibronectin.

3. Reparation of the site of implantation defect at the point of invasion via close plug(operculum) which comprises blood clot and cellular debris

4. Formation of uteroplacental circulation.

5. Manifestation of decidual reaction. Featuring:

• accumulation of glycogen and lipids by ESCs - endometrial stromal cells

• formation of more capillaries around conceptus

• increase in glandular activities of stroma cells- secretion of enzymes

•

Front 41

The normal site of implantation is the_______?

Back 41

Posterior wall of mid portion of the uterus

Front 42

Ectopic sites are

Back 42

•Ampullary

•isthmic

• cornual

• abdominal or ovarian

Front 43

A space develops with accumulation of fluid within the epiblast, which is called _______?

Back 43

Amniotic cavity

Front 44

The trophoblast is differentiated into:

Back 44

Cytotrophoblast and syncytiotrophoblast

Front 45

An outer layer of multinucleated cell without distinct cell boundaries

Back 45

Syncytiotrophoblast

Front 46

Formation of the AVE-_____, establishes the ____________

Back 46

•Anterior visceral endoderm

•dorsal-ventral and cranio-caudal axes

Front 47

During day 8, fluid accumulates between the epiblast to form_______

Back 47

Amniotic cavity fluid

Front 48

At day 9, three things happen

Back 48

1. The blastocyst becomes deeply embedded in the endometrium with Closure of implantation defect by fibrin clot

2. Formation of spaces within the syncytiotrophoblast cells called - Lacunae

3. Some of the hypoblast cells migrate to form a membrane called the exocoelomic (Heuser) membrane over the cytotrophoblast. And the cavity created by the boundaries of the Heuser membrane and the hypoblast cells is called the primitive yolk sac/exocoelomic cavity.

Front 49

4 things happens btw day 11&12

Back 49

1. The blastocyst becomes completely embedded in the endometrial stroma.

2. The lacunae of the syncytiotrophoblast merges the stromal capillaries to form sinusoids, establishing the uteroplacental circulation.

3. New cells develop between the cytotrophoblast and the Heuser membrane called the extraembryonic mesoderm EEM

4. The EEM bear develops spaces which will layer formyhe chorionic cavity. The EEM closer the cytotrophoblast is splanchnopleuric.

While the one adjacent to the primitive yolk sac is somatopleuric.

Front 50

On the 13th day, three things happen/ are observed:

Back 50

1. The cytotrophoblast begins to grow into the syncytiotrophoblast via finger like projections called primary villi

2. New cells from the hypoblast migrate to the inner part of the Heuser membrane and causes a large pinch off from the primitive yolk sac called the secondary/definitive yolk sac. A smaller exocoelomic cyst is seen embedded in the extraembryonic cavity

3. The embryonic part is then seen to be attached to the cyto trophoblast by just a connecting stalk which would later become the umbilical cord.