Lecture 3 - Prenatal Development and Pregnancy

Question 1

What is the importance of prenatal development?

Answer 1

Fastest growth of body and brain, basis for further development

Question 2

What is conception?

Answer 2

The fusion of 1 egg cell and 1 sperm cell, happens during ovulation

Question 3

What is a zygote?

Answer 3

Fertilized egg cells

Question 4

Why is the zygote diploid?

Answer 4

Contains 46 chromosomes, carries the complete genetic material

Question 5

What is a gamete?

Answer 5

Sperm or egg

Question 6

Why is the gamete haploid?

Answer 6

Contains 23 chromosomes, half of the genetic material necessary to form an organism

Question 7

Why are monozygotic twins identical?

Answer 7

They develop form 1 egg cell and 1 sperm cell

Question 8

Which chromosome is the sex chromosome?

Answer 8

23 - only chromosome not necessary for survival

Question 9

Explain the (XXY) Klinefelter syndrome?

Answer 9

Affects men.
Long body and limbs, low testosterone, fertility problems.
XXXY or XXXXY forms have lower IQ.
Requires hormone therapy

Question 10

Explain the (X0) Turner syndrome

Answer 10

Affects females with only 1 X chromosome. Underdeveloped secondary sex characteristics, low estrogen, fertility problems, short body and limbs

Question 11

Explain Trisomy 21 (aka Down Syndrome)

Answer 11

There are three 21 chromosomes.
Dependent on the age of the mother.
Intellectual disability, short body, lower life expectancy, higher risk of Alzheimer’s

Question 12

What is chorionic villus sampling (CVS)?

Answer 12

Withdrawal of cells from placenta, increases chance of miscarriage

Question 13

Nuchal fold thickness

Answer 13

Fluid of the neck > If thicker there is a change for Down syndrome

Question 14

Which are the phases of prenatal development?

Answer 14

Germinal (0-2), embryonic (3-8), fetal (9-40)

Question 15

What happens during the germinal phase?

Answer 15

Development into blastocyst. It’s a very sensitive phase, high chance of miscarriage.

Question 16

What is a blastocyst?

Answer 16

Layered cell mass with a cavity > later forms the embryo

Question 17

Which are the layers of the blastocyst?

Answer 17

Endoderm, mesoderm, ectoderm

Question 18

What is the endoderm layer?

Answer 18

Becomes the digestive and respiratory system

Question 19

What is the mesoderm layer?

Answer 19

Becomes the muscles and skeletal system

Question 20

What is the ectoderm layer?

Answer 20

Becomes the skin and nervous system

Question 21

What is organogenesis?

Answer 21

Formation of organs

Question 22

When does the circulatory system form?

Answer 22

3rd week - baby hooks up to maternal blood system

Question 23

___ folds into the neural tube

Answer 23

The ectoderm

Question 24

Which are the 3 principles of prenatal development?

Answer 24

Proximodistal order (from in to out), cephalocaudal order (from top to bottom), mass to specific (from rough to detailed)

Question 25

Which are the steps of the development of neuronal networks in the fetal phase?

Answer 25

Neurulation, neuronal proliferation, neural migration

Question 26

What happens during neurolation?

Answer 26

Formation of the neural tube

Question 27

What happens during neuronal proliferation?

Answer 27

Fast formation of neurons (embryonic and fetal phase)

Question 28

What happens during neural migration?

Answer 28

Neurons go to the right areas of the brain and begin to form connections

Question 29

What is the age of viability?

Answer 29

22-23 weeks

Question 30

Define the term teratogen

Answer 30

Substance that cross the placenta and are harmful influences on the unborn child

Question 31

When are teratogens most harmful and why?

Answer 31

During the embryonic phase. Because that's when the organs and brain start to form

Question 32

When do teratogens affect brain development the most?

Answer 32

2nd and 3rd trimester

Question 33

Why are teratogens dose dependent?

Answer 33

The more a mother uses a harmful substance, the stronger the effects and higher the risks

Question 34

The severity of teratogens depend on individual differences. Why?

Answer 34

It depends on fetal and maternal genetic vulnerabilities

Question 35

What was the harmful effect of Softenon?

Answer 35

Birth of children with missing or underdeveloped limbs

Question 36

What are the consequences of smoking during pregnancy?

Answer 36

Nicotine constricts blood vessels > reduced blood flow > less nutrition and oxygen

Question 37

When is nicotine's effect the strongest during pregnancy?

Answer 37

3rd trimester

Question 38

What are the consequences of nicotine consumption during pregnancy?

Answer 38

Increased risk of miscarriage, premature birth, asthma, cognitive problems, behavioral regulation problems