Development Flashcards

1
Q

Gestation Period

A

The time span from fertilization to birth ( 38 weeks )

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

Prenatal period ( before birth )

A

Embryological development: developing human for the first 2 months after fertilization ( the embryo )
Fetal development: from 9 weeks until birth ( is not the fetus and not the embryo )
By the end of the 3rd month, the placenta is now functioning

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

Events before fertilization

A

This all occurs in the uterine tubes within 24 hours after ovulation
Fertilization likely 2 days before to 1 day after ovulation
Oocyte travels towards the uterus through the uterine tubes and the movement of cilia
The sperm swim towards the oocyte by flagella
-uterine contractions help the sperm move towards the oocyte
Final maturation of the sperm occurs inside the female
-acrosomal membrane becomes fragile
Sperm spends 7 hours in the female reproductive tract before capable of fertilization
*sperm only survives 48 hours in female
*Oocyte viable 24 hours after ovulation

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

Embryonic period

A

Extends from fertilization through the eighth week of development

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

Fertilization

A

The merging of genetic information between a

Haploid sperm cell and a haploid secondary oocyte merging into a single diploid nucleus

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

Fertilization of an egg

A

Sperm penetrates the corona radiata and the zona pellucida around the oocyte

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

Acrosome enzymes

A

allows the sperm to penetrate the corona radiata

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

Fertilization cycle

Day1-12

A
  1. Zygote
    Day 1: Begins mitotic division, known as cleavage. First division takes about 6 hours
    Day 2: two days after fertilization, a second cleavage is completed, now 4 cells (blastomeres)
    Day 3: there are 16 cells. all small cells are blastomeres
    Day 4: the clusters are now a morula, still surrounded by the zona pellucida
    On day 4 or 5: Morula enters uterine cavity, nourished by the uterine milk.
    At the 32 cell stage , the fluid inside morula rearrange the blastomeres into blastocyst.
    Day 6 or 7: blastocyst implants to endometrium wall of uterus
    Day 8: trophoblast develops into syncytiotrophoblast and cytotrohoblast, becoming part of the chorion.
    The embryo blast develops two layers, cells of those structures form bilaminar embryonic disc.
    The amniotic cavity forms from the epiblast & fills with amniotic fluid
    Yolk sac is formed
    Day 9: lacunae form
    Day 12: yolk sac and lacunae form lacunar networks
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Blastocyst

A

Two cells populations:

Embryoblast and trophoblast

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

Placenta

A

provides nutrients to embryo

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

The chorion

A

Blocks antibody production by the mother
Promotes the production of T lymphocyte
Produces human chorionic gonadotropin
Secretes estrogens after the first 3-4 weeks of pregnancy and progesterone by the 6th week

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

Gastrulation

A

first major event of the 3rd week

  • Bilaminar disc transforms into a two dimensional trilaminar disc, made up of ectoderm, mesoderm and endoderm
  • Involves rearrangement and migration of epiblast cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Placentation

A

Process of forming the placenta
Produced hormones used to sustain the pregnancy
Site of exchange for nutrients and wastes between the mother and fetus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Placenta

A

Two parts
Fetal portion
maternal portion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

True labor

A

Stage of dilation
Stage of expulsion
Placental stage

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

Development anatomy

A

The study of the sequence of events from the fertilization of a secondary oocyte to the formation of an adult organism

17
Q

Syngamy

A

The fusion of a sperm with a secondary oocyte

18
Q

Dizygotic twins

A

Fraternal twins

Produced from the independent release of two ova and the subsequent fertilization of each by different sperms

19
Q

Monozygotic twins

A

Derived from a single fertilized ovum that splits at an early stage in development
Contain exact same genetic material and always the same sex

20
Q

Yolk Sac

A

Transfers nutrients to the embryo, is an early source of blood cells and produced primitive germ cells

21
Q

Capacitation (ZP3)

A

The series of functional changes that prepare its plasma membrane to fuse with oocyte’s

22
Q

Polyspermy

A

The fusion of sperm cells and oocytesets in motion events to block another sperm from fertalizing the egg

23
Q

Embryoblast

A

Inner cell mass- develops into embro

24
Q

Trophoblast

A

Outer layer that forms wall and will ultimately develop into outer chronic sac surrounding fetus and fetal portion of placenta

25
Q

Implantation

A

7 days after fertilization, it attaches more firmly and burrows in
Endometrium becomes more vascularized and glands enlarge
now called a dicidua (endometrium that is modified after implantation )

26
Q

Development of trophoblast

A

Day 8.
Digests its way into endometrium(dicidula), to become part of the chorion (where vasculature develops)
Now secretes hCG, signals corpus luteumn to stay in place and not shed ( aka period)
Which leads to estrogen and progesterone continue to secrete
THIS STOPS MENSTRATION FROM OCCURING NOW GOES A DIFFERENT PATH

27
Q

Development of bilaminar disc

A

8 days after fertilixzation

Cells of embryoblast, into 2 layers : hypoblast & epiblast

28
Q

Development of amnionic fluid

A

Amnion forms roof of amniotic cavity and epiblast forms floor
Amnion eventually surrounds the entire embryo, cavity is now filled with amniotic fluid

29
Q

Development of yolk sac

A

from exocoelomic membrane
Relativley small and empty since nutrition derived from endometrium
Will give a rise to easy nutrients, source of blood cells, germ cells that will migrate to form gametes, form part of the gut, shock absorber and prevent desiccation

30
Q

Development of sinusoids

A

creating endometrium capillaries dilate to form maternal sinusoids,
more material will diffuse into and will allow chorion to develop

31
Q

Cloacal membrane

A

Once it appears in gastrulation, wall of yolk sac forms allantois

32
Q

Development of somites

A

3 regions

myotome: skeletal muscles of neck, trunk and limbs
dermatome: connective tissue
sclerotome: vertebrae and ribs

33
Q

Angiogenisis

A

Formation of blood vessels

By end of 3rd week, heart forms and begins to beat

34
Q

Process of forming placenta

A

2 umbilical arteries carry deoxygenated fetal blood to placenta
1 umbilical vein carries oxygenated blood away from placenta

Afterbirth it detaches from uterus

35
Q

Hormones of pregnancy

A

3-4 months: corpus lute secretes estrogen and progesterone
3rd month on the Placenta produces high levels of estrogen and progesterone and produces CRH
Chorion secretes hCG and produces hCS
Relaxin is produced by corpus lute and placenta

36
Q

LAbor

A

expelled from uterus through vagina
estrogen rises to overcome effect if progesterone on contractions
estrogen increases number of receptors for oxycontin, which stimulates contractions
Relaxin increases flexibility of pubic synthesis and dilates the cervix

37
Q

Control of labor through positive feedback

A

Contractions force fetal head to the cervix which stretches
stretching causes release of more oxycontin
more oxycotin=more stretching

38
Q

Adjustnentf of infants after birth

A

Foramen vale closes
-diverts blood to lungs for the first time
now called fossa ovalis
Ductus arterioles constricts and becomes the ligaments arteriosum
Umbilical arteries become medial umbilical ligaments and umbilical been becomes round ligaments of the liver

39
Q

Lactation after birth

A

Prolactin promotes milk secretion
secreted by anterior pit.
After delivery, inhabitation removed as estrogen and progesterone levels fall and prolactin can begin
-Sucking maintains prolactin secretion