Brainscape's Knowledge GenomeTM

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


See full index

RGU Exam 2 > Physiology of Conception and Placentation > Flashcards

Physiology of Conception and Placentation Flashcards

1
Q

Embryologic age defintion

A
  • From fertilization on, gestation = 38wks
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Menstrual age definition

A
  • From LMP, gestation = 40wks
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Preembryonic period

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

Embryonic period

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

Fetal period

A
  • Weeks 9-birth
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Oogenesis key features

A
  • Mitosis in fetus only
  • Meiotic arrests
  • Polar bodies
  • Large single cell
  • Immotile cell
  • 23X
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Spermatogenesis key features

A
  • Limited mitosis in fetus
  • Continuous mitosis at puberty till death
  • No meiotic arrests
  • 4 mature sperm from 1 spermatocyte
  • Small, motile cell
  • 23X or 23Y
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Oogenesis vs. Spermatogenesis Graph

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

Egg Maturation

A

1) embryonic oogonia are naked
2) After meiosis oogonia are surrounded = primordial follicles
3) At birth, primary oocytes have complete layer = primary follicle
4) Early and late secondary follicles (has >1 surrounding)
5) Maturing
6) Mature = Graafian follicles
7) Ovulation
8) Post-ovulation Corpus Luteum
9) Post-ovulation Corpus Albicans

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

Ovum lifespan

A
  • 12-24hrs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Sperm lifespan

A
  • 48-72hrs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

When is fertilization most likely to occur?

A
  • When intercourse occurs within the 2-3 days perior just prior to ovulation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Egg Transport

A
  • Egg arrested in Meiosis II
  • Lots of cytoplasm, corona radiata, zona pellucida
  • Ciliated cells enlarge, more cilia, beat faster
  • Secretory Peg cells more active
  • Fimbriae move closer, beat
  • Peristalsis propels
  • 80% time spent in ampulla
  • Chemoattractants
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Spermatogenesis

A
  • Several divisions of spermatogonia happening in closs association w/ sertoli cells

*Type A dark spermatogonia—>Type A pale spermatogonia (multiple divisions)—>Type B spermatogonia—>Primary spermatocytes (undergoes 1st meiotic division to become…)—>Secondary spermatocytes (undergoes 2nd meiotic division to become…)—>Spermatids—>Spermatozoa

  • Once Spermatozoa is fully developed, it moves to the lumen of seminiferous tubules. Moving thru epididymis, it gains full motility and a glycoprotein coat
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Sperm transport

A
  • Of ~200-600 million/ejaculate, about 200-300 reach egg
  • Loss by expulsion of semen, by vaginal enzymes, phagocytosis
  • Seminal vesicles work to counteract

*vesiculase and fibrinogen from coagulates sperm, to prevent backflow

*prostaglandins in semen may stimulate uterine contractions

*fructose from provides energy for sperm

  • May be stored in crypts, gradually released
  • Midcycle estrogen peak; high mucus production w/ high water content and space b/w glycoproteins
  • Capacitation may be initiated as sperm pass thru cervix
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Sperm capacitation

A
  • Changes surface characteristics of sperm, affects motility
  • Hyper-activated motility in ampulla, result of capacitation, interaction w/ tubal epithelium

*result: greater speed, better direction, prevention of attachment and entrapment

  • Results in decreased stability of plasma membrane and acrosomal membrane so will be able to fuse later in acrosomal reaction
17
Q

Penetration of egg coverings

A
  • Corona radiata = cellular layer w/ extracellular matrix heavy w/ hyaluronic acid

*chemoattractants to guide sperm

*tubal mucosal cells may aid in dispersion of corona radiata cells

  • Zona pellucidae (ZP) = 3 glycoproteins (ZP1-3)

*ZP 3 acts as sperm receptor and stimulates acrosomal reaction

*ZP prevents implantation in fallopian tubes

  • Swimming aids in penetration
  • Binding to Zona Pellucida-3 stimulates acrosomal reaction
  • Acrosomal reaction- aids in pentration of membranes
18
Q

Binding and fusion of sperm and egg

A
  • Sperm now in perivitelline space
  • Molecules on sperm head bind to integrin molecules on egg membrane
  • Sperm and egg membranes fuse, contents of sperm sink into egg and sperm plasma membrane incorporated into egg membrane
  • Mitochondria from sperm enter, degraded by proteasome. Tail also degraded except for centriole, used for sperm aster later.
19
Q

Prevention of Polyspermy (Zona Reaction)

A

Fast block- lasts ~5min

  • Rapid depolarization of egg plasma membrane within 2-3sec.
  • Prevents other sperm from binding and trigger metabolic activity in egg

Slow block- permanent

  • Calcium wave sweeps across egg from site of sperm-egg fusion, released from internal stores in egg
  • Cortical granules fuse w/ plasma membrane, exocytosis, release contents into perivitelline space

*polysaccharides attract water, ZP elevates

*ovoperoxidase hydrolyzes the sperm receptors in membranes, kills sperm

*structural proteins of ZP become cross-linked and sperm binding molecules inactivated

  • Completion of Meiosis II occurs after
20
Q

Fusion of pronuclei and loss of pronuclear membrane

A
  • After completion of meiosis II
  • Male and female pronuclei come together, chromosomes intermingle, now called zygote
  • Egg activation occurs after
21
Q

Blastocyst composition

A
  • Outside layer of trophoblast cells

*give rise to extraembryonic structures like placenta

  • Inner cell mass

*give rise to embryo itself

22
Q

Klinefelter Syndrome

A
  • Extra X chromosomes; the more X-chromosomes the more likely to have cognitive impairment

*e.g. XXXY, XXYY, XXXYY

23
Q

Turner’s Syndrome

A
  • 45, X karyotype, only monosomy compatible w/ life. 2% of fetuses survive

*e.g. XO

24
Q

Super-female

A
  • Triple X (XXX) Syndrome
  • Often undiagnosed
  • Some speech impediment
25
Q

Super-male

A
  • XYY
  • Hypogonadal
  • Infertile
  • Cognitive impairment
26
Q

Early Implantation

A
  • Blastocyst reaches uterus b/w 3-4 days, remains in uterine avity 1-3 days before implantation
  • Days 6-9, embryo implants into midportion of posterior wall of uterus
  • Inner cell mass proliferates into the two-germ-layer stage of embryo epiblast and hypoblast
27
Q

Late implantation

A
  • Embryo will sink into stroma of endometrium, original site will heal over
  • Requires complex preparation by hormones stimulating uterus
  • Epiblasts cells become primitive amnion
  • Hypoblast cells becoming yolk sac
28
Q

Source of nutrition graph

A
29
Q

Amnion germ cell layers

A
  • Epiblast/ectodermal cells

*later lined by mesoderm

30
Q

Yok sac germ cell layers

A
  • Hypoblast/endodermal cells
31
Q

Allantois germ cell layer

A
  • Hypoblast/endodermal cells
32
Q

Chorion germ cell layer

A
  • Cytotrophoblast/mesodermal
33
Q

Decidua basalis

A
  • B/w chorionic vesicle and uterine wall, w/ growth it is incorporated into maternal component of placenta
34
Q

Decidua capsularis

A
  • Overlies the embryo
35
Q

Decidua parietalis

A
  • Endometrium on sides of uterus not occupied by embryo
36
Q

Amniocentesis

A
  • Tests for genetic defects, neural tube defects by measuring alpha feto protein directly
  • Done at 15-16wks, can be done earlier but have higher fetal losses
37
Q

Chorionic villus sampling

A
  • Can detect chromosomal abnormalities, X-linked disorders, and metabolic problems
  • Slightly more risky than amniocentesis
  • Advantage is it can be performed weeks earlier
38
Q

Formation of early placenta

A
  • Chorionic villi become more highly branched and the layers become thinner w/ growth of placenta

*primary (small projections), wk 2

*secondary (CTB+mesenchyme)

*tertiary (+fetal blood vessels), wk 3

39
Q

Formation of late/mature placenta

A
  • Chorionic villi become more highly branched and the layers become thinner w/ growth of placenta

*anchoring (direct contact w/ maternal tissues wk5)

*mature (by term reaches >1billion microvilli/cm2 = high surface area)

RGU Exam 2 (21 decks)

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