Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

GIGU > Fertilization and Implantation > Flashcards

Fertilization and Implantation Flashcards

1
Q

Both the sperm and the oocyte must travel to where for fertilization?

A

Ampulla of oviduct

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What must happen in order to expose binding sites of the sperm for the ooctye’s zona pellucida?

A

Sperm Capacitation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Epididymal sperm’s plasma membrane is coated with what?

A

Many surface molcules/proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

The sperm that is then ejaculated becomes coated with?

A

Seminal plasma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Describe seminal plasma

A

Seminal plasma proteins coat the surface molecules on the sperm that is ejaculated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Once the ejaculated sperm reaches the female tract, then what occurs?

A

Capacitation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Describe capacitation

A

The seminal plasma coatings and sperm surface molecules are REMOVED to expose portions of the sperm that can bind with the oocyte’s zona pellucida

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Incapacitated sperm (have yet to undergo capacitation) can bind to?

A

Epithelial cells in the oviductal isthmus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What does the binding of incapacitated sperm to the isthmus do?

A

Extends the sperm lifespan

INCREASES the probability that the sperm will be in the oviduct when the egg is ovulated!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Once incapacitated sperm are capacitated what happens?

A

They are unbound from the isthmus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What creates a hyperactive sperm?

A

Sperm capacitation + Chemical signals from oocyte

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Hyperactivation of sperm results in what physical change?

A

A change in flagella motion from wave-like to whip-like

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What 3 things does hyperactivation of sperm help with?

A
  1. Increases sperm mobility
  2. Detaches sperm from the epithelium
  3. Helps propel the sperm through the outer layers of the egg to reach the plasma membrane
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What 3 barriers must be breached during fertilization?

A
  1. Expanded cumulus (corona radiata)
  2. Zona pellucida
  3. Oocyte plasma membrane
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the cumulus cell matrix of the oocyte made of?

A

Hyaluronic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What does the sperm use to digest the cumulus cell matrix of hyaluronic acid?

A

Hyaluronidase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

The zona pellucida of the oocyte contains glycoproteins. Which one does the sperm have a receptor for?

A

ZP3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Once the sperm binds ZP3 on the oocyte, what happens next?

A

Acrosome reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Describe the acrosome reaction

A
  • The sperm’s plasma membrane fuses with its acrosomal membrane
  • This causes release of acrosomal enzymes
  • These enzymes digest the zona pellucida locally
  • The sperm can then push forward toward the plasma membrane of the oocyte
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What protein does the sperm possess to bind to the oocyte plasma membrane?

A

Izumo protein of the sperm binds to the Izumo receptor on the oocyte plasma membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Once the sperm Izumo protein binds to its receptor on the oocyte, then what happens?

A

The sperm enters the egg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Once the sperm enters the egg, list the main things that occur next

A
  • Sperm DNA de-condenses
  • Pronucleus membrane forms around DNA
  • Cortical reaction
  • Male and female chromosomes replicate as pronuclei move together
  • Fusion of pronuclei = beginning of embryonic development!
23
Q

Describe the cortical reaction

A

Triggered by the fusion of the egg and the sperm

- Release of Ca++ alters zona pellucida proteins that BLOCKS the binding of other sperm to prevent polyspermy

24
Q

What does the cortical reaction prevent?

A

Polyspermy (binding of additional sperm to the oocyte)

25
Q

Cleavage

A

Cell division without growth

26
Q

Main steps in week 1 embryonic development

A

Cleavage
Embryo reaches 16 cell stage morula
Early blastocyst
Implantation

27
Q

Around what day is implantation

A

Day 8

28
Q

What is blastocyst hatching?

A

Hatching of the embryo from the zona pellucida prior to implantation

29
Q

Inability for the blastocyst to hatch can result in?

A

Infertility

30
Q

Premature blastocyst hatching can result in?

A

Abnormal implantation

31
Q

hCG

A

Human Chorionic Gonadotropin

32
Q

What secretes hCG?

A

Trophoblasts and Syncytiotrophoblasts

33
Q

What are the functions of hCG?

A

Prevents menstruation
Increases progesterone and estrogen secretion
Stimulates trophoblast and placental growth

34
Q

What are the main stages of implantation?

A
  1. Apposition
  2. Attachment
  3. Invasion
35
Q

Describe the apposition phase of implantation

A

Contact between the endometrium and trophoblasts

  • Usually in a crypt of endometrium
  • Inner cell mass rotation near endometrial epithelium
36
Q

Describe the attachment phase of implantation

A

Trophoblast cells adhere to endometrial epithelium

- Initiates decidualization

37
Q

Describe the invasion phase of implantation

A

Degradation of endometrial epithelial cells AND

Trophoblast fusion and formation of syncytiotrophoblasts

38
Q

What can the syncytiotrophoblasts do during implantation?

A

Protrude through basement membrane and reach endometrial stromal cells

39
Q

Main attributes of syncytiotrophoblasts?

A
  • Express surface adhesive proteins
  • Breakdown of endometrial extracellular matrix
  • Secrete hCG
  • Phagocytosis and bidirectional transfer of materials
40
Q

What are the things syncytiotrophoblasts can secrete to help break down the endometrial extracellular matrix?

A

Metalloproteinases and Angiogenic factors

41
Q

Decidualization occurs in what phase of implantation?

A

Attachment

42
Q

Decidualization

A

Maternal stromal cell changes in response to invasion and progesterone

43
Q

During decidualization, what do the stromal cells change to?

A

Enlarged, glycogen-filled cells

44
Q

After decidualization, the endometrium is called?

A

Decidua

45
Q

After decidualization, the endometrium is ready for?

A

Implantation

46
Q

What 2 things does the decidua do?

A
  1. Forms sheet with adhesive junctions to inhibit migration of embryo
  2. Production of signals to prevent embryo from invading myometrium
47
Q

If the decidua does not not allow the embryo to invade the myometrium, what can occur?

A

Postpartum hemorrhage

48
Q

Ectopic implantation

A

Implantation anywhere other than the fundus of the uterus

49
Q

With an ectopic implantation, what does not occur?

A

Decidualization

50
Q

Since decidualization does not occur with an ectopic pregnancy, the invasion is NOT controlled. What will this cause?

A

Rupture of tissues = hemorrhage

51
Q

Placentation

A

Spaces appear within syncytiotrophoblasts around day 9

- Formation of primary, secondary and tertiary villi

52
Q

Primary villus

A

Syncytiotrophoblasts and cytotrophoblasts

53
Q

Secondary villus

A

Primary villus + mesenchyme

54
Q

Tertiary villus

A

Secondary villus + fetal blood vessels formed de novo

GIGU (29 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions