Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
34 Cards in this Set
- Front
- Back
|
When are the most visible changes occurring during prenatal development?
|
3-8 weeks
|
|
|
How is the gestational age of the fetus calculated?
How is it different from the fertilization age? |
from the 1st day of the last normal period
This is 2 weeks longer that the fertilization age because the ooocyte is not fertilized until approx 2 weeks after the preceding menstration |
|
|
What is the result of cleavage of the zygote?
|
blastomeres
|
|
|
What is a morula?
|
solid mass of approx 12-32 blastomeres
this stage occurs 3-4 days after fertilization |
|
|
How do the blastomeres stick together during the Morula stage?
What is this process called? |
Probably mediated by cell surface adhesion glycoproteins
this phenomenon of forming a compacted ball of cells is called compaction |
|
|
How can you determine a morula from a blastocyst?
|
the blastocyst has a fluid filled cavity
|
|
|
Approx how many days pass between fertilization and implantation?
|
6
|
|
|
What stage comes directly after implantation?
|
gastrulation
|
|
|
In what stage does the 3 germ layers differentiate into tissues and organs?
|
gastrula stage (3rd week)
|
|
|
What happens after gastrulation?
|
Neurula
First site of the nervous system. When the neural tube is developing from the neural plate. |
|
|
How are the size of embryos measured?
|
Crown-rump length
|
|
|
What is the length of the embryonic period?
|
extends to the end of the 18th week
56 days all major structures are present |
|
|
What day does the fetal period begin and end?
|
day 57 (9th week - birth)
when the fetus is outside the mother |
|
|
What is conceptus?
|
The embryo and its adnexa (or associated membranes)
|
|
|
What is primordium?
|
the first discernible indication of an organ or structure
|
|
|
Which stage, embryonic or fetal, is more dramatic in terms of development?
|
embryonic
fetal period is mainly elaboration and growth of the organs that appears during the embryonic stage |
|
|
At what week is sex clearly distinguishable?
|
Week 12
|
|
|
What week is the fetus viable?
|
week 22
|
|
|
What is a threatened abortion?
|
bleeding with the possibility of abortion
|
|
|
Describe a spontaneous abortion.
|
Usually during the first 12 weeks
15% of recognized pregnancies most common in week 3 |
|
|
What is habitual abortion?
|
expulsion of a dead or non-viable embryo in 3 or more consecutive pregnancies.
|
|
|
What is induced abortion?
|
A birth that is medically induced before the fetus is viable
(before 20 weeks) |
|
|
What is complete abortion?
|
one in which all products of conception are expelled
|
|
|
What is a missed abortion?
|
the retention of a conceptus in the uterus after death of the embryo or fetus
|
|
|
What is a miscarriage?
|
spontaneous abortion before the middle of the 2nd trimester
(135 days) |
|
|
What is a trimester?
|
A period of 3 calendar months
|
|
|
The most critical stages of development occur in what trimester?
|
1st
|
|
|
What period is described as infancy?
newborn or neonate? |
1st year after birth
1 month or younger |
|
|
What is the childhood stage?
|
13 months to puberty
|
|
|
When does puberty occur in both males and female?
|
females: 12-15
males: 13-16 |
|
|
What is the sign that puberty has ended in both males and females?
|
first period (menarche)
mature sperm produced |
|
|
What stage in life is does one acquire the ability to reproduce?
|
adolescence
Years 11-19 |
|
|
What is the division of embryology that deals with abnormal development? (birth defects)
|
Teratology
|
|
|
Most of the time, birth defects cause death in what stage?
|
infancy
|
