Topic 1 - Prenatal Development Flashcards
Typical prenatal development, which begins with fertilization and ends with birth, takes between _____
266 and 280 days (38 to 40 weeks).
Typical prenatal development, which begins with _____ and ends with _____, takes between 266 and 280 days (38 to 40 weeks).
fertilization
birth
three periods of prenatal development
Germinal
Embryonic
Fetal
period of prenatal development that takes place during the first two weeks after conception.
Germinal period
It includes the creation of the fertilized egg, called a ___
zygote
-specialization of cells to perform various tasks-starts to take place approximately one week after conception.
Differentiation
consists of an inner mass of cells that will eventually develop into the embryo
blastocyst
an outer layer of cells that later provides nutrition and support for the embryo.
trophoblast
the attachment of the zygote to the uterine wall, takes place about 11 to 15 days after conception.
Implantation
is the period of prenatal development that occurs from two to eight weeks after conception.
embryonic period
This period begins as the blastocyst attaches to the uterine wall.
embryonic period
The mass of cells is now called an _____
embryo
three layers of cells form in embryonic period
endoderm
Mesoderm
Ectoderm
is the inner layer of cells, which will develop into the digestive and respiratory systems.
endoderm
is the middle layer, which will become the circulatory system, bones, muscles, excretory system, and reproductive system.
mesoderm
is the outermost layer, which will become the nervous system and brain, sensory receptors (ears, nose, and eyes, for example), and skin parts (hair and nails, for example).
ectoderm
The endoderm primarily produces ____, the mesoderm primarily produces parts that surround the _____, and the ectoderm primarily produces ______.
internal body parts
internal areas
surface parts
As the embryo’s _____ form, life-support systems for the embryo develop rapidly.
3 layers
3 Lie support systems
Amnion
Umbilical cord (both of which develop from the fertilized egg, not the mother’s body)
Placenta
is a sac (bag or envelope) that contains a clear fluid in which the developing embryo floats.
amnion
provides an environment that is temperature and humidity controlled, as well as shockproof.
amniotic fluid
during this period, the rate of cell differentiation intensifies, support systems for cells form, and organs appear.
embryonic period
contains two arteries and one vein, and connects the baby to the placenta.
umbilical cord
consists of a disk-shaped group of tissues in which small blood vessels from the mother and the offspring intertwine but do not join.
placenta
is the name given to the process of organ formation during the first two months of prenatal development.
Organogenesis
when was the neural tube that eventually becomes the spinal cord form?
In the third week after conception
At about ____ eyes begin to appear, and at _____ the cells for the heart begin to differentiate
21 days
24 days
During the ____ week, the urogenital system becomes apparent, and arm and leg buds emerge.
fourth
During the fourth week, the _____ becomes apparent, and arm and leg buds emerge.
urogenital system
From the ______ week, arms and legs differentiate further; at this time, the face starts to form but still is not very recognizable. The intestinal tract develops and the facial structures fuse.
fifth to the eighth
At ____ weeks, the developing organism weighs about 1/30 ounce and just over 1 inch long.
8
At eight weeks, the developing organism weighs about ____ ounce and just over ____ long.
1/30
1 inch
lasting about seven months, is the prenatal period between two months after conception and birth in typical pregnancies.
fetal period
the fetus is about 3 inches long and weighs about four-fifths of an ounce. Its arms, legs, and head move randomly (or spontaneously), and its mouth opens and closes. The face, forehead, eyelids, nose, and chin are distinguishable, as are the upper arms, lower arms, hands, and lower limbs. In most cases, the genitals can be identified as male or female.
Three months after conception (13 weeks)
Three months after conception (13 weeks), the fetus is about ____ long and weighs about ____ of an ounce.
3 inches
four-fifths
By the ______ the fetus has grown to about 5.5 inches in length and weighs about 5 ounces. At this time, a growth spurt occurs the body’s lower parts. For the first time, the mother can feel the fetus move.
end of the fourth month of pregnancy (17 weeks),
By the end of the fourth month of pregnancy (17 weeks), the fetus has grown to about ____ in length and weighs about ____ ounces. At this time, a growth spurt occurs the body’s lower parts. For the first time, the mother can feel the fetus move.
5.5 inches
5
By the _____ , the fetus is about 12 inches long and weighs close to a pound. Structures of the skin have formed-toenails and fingernails, for example. The fetus is more active, showing a preference for a particular position in the womb.
end of the fifth month (22 weeks)
By the end of the fifth month (22 weeks), the fetus is about _____ long and weighs close to a pound. Structures of the skin have formed-toenails and fingernails, for example. The fetus is more active, showing a preference for a particular position in the womb.
12 inches
By the end of the _____, the fetus is about 14 inches long and has gained another half pound to a pound. The eyes and eyelids are completely formed, and a fine layer of hair covers the head. A grasping reflex is present and irregular breathing movements occur.
sixth month (26 weeks)
By the end of the sixth month (26 weeks), the fetus is about ____ long and has gained another half pound to a pound. The eyes and eyelids are completely formed, and a fine layer of hair covers the head. A _____is present and irregular breathing movements occur.
14 inches
grasping reflex
As early as _____, the fetus for the first time has a chance of surviving outside the womb-that is, it is viable.
six months of pregnancy (about 24 to 25 weeks after conception)
Infants who are born early, or _____ weeks of pregnancy, usually need help breathing because their lungs are not yet fully mature
between 24 and 37
By the end ____, the fetus is about 16 inches long and weighs about 3 pounds.
the seventh month
By the end the seventh month, the fetus is about ____ long and weighs about ____.
16 inches
3 pounds
During the of____ prenatal development, fatty tissues develop, and the functioning of various organ systems-heart and kidneys
last two months
During the ____ months, the fetus grows longer and gains substantial weight-about another 4 pounds.
eighth and ninth
During the eighth and ninth months, the fetus grows longer and gains substantial weight-about another ____. .
4 pounds
At birth, the average American baby weighs ____and is about ____ long.
8 pounds
20 inches
One of the most remarkable aspects of the prenatal period is the ____
development of the brain
By the time babies are born, it has been estimated that they have as many as ____
20 to 100 billion neurons, or nerve cells
During prenatal development, ____ spend time moving to the right locations and are starting to become connected.
neurons
The basic architecture of the human brain is assembled during the ____ of prenatal development.
first two trimesters
____of prenatal development and the _____ are characterized by gradual increases in connectivity and functioning of neurons.
third trimester
first two years of postnatal life
Four important phases of the brain’s development during the prenatal period involve:
(1) the neural tube
(2) neurogenesis
(3) neuronal migration
(4) neural connectivity.
is any agent that can potentially cause a birth defect or negatively alter cognitive and behavioral outcomes.
teratogen
The type or severity of abnormalities caused by a teratogen is linked to the genotype of the pregnant woman and the genotype of the embryo or fetus
Genetic susceptibility
is rather obvious-the greater the dose of an agent, such as a drug, the greater the effect
Dose
Exposure to teratogens does more damage when it occurs at some points in development than at others
Time of exposure
the____ period is more vulnerable than the ____ period.
embryonic
fetal
that can function as teratogens include antibiotics, such as streptomycin and tetracycline; some antidepressants; certain hormones, such as progestin and synthetic estrogen; and Accutane (the trade name for isotretinoin, a form of Vitamin A that is often used to treat acne)
Prescription drugs
(the trade name for isotretinoin, a form of Vitamin A that is often used to treat acne)
Accutane
that can be harmful include diet pills and high dosages of aspirin
Nonprescription drugs
act on the nervous system to alter states of consciousness, modify perceptions, and change moods. Examples include caffeine, alcohol, and nicotine, as well as illicit drugs such as cocaine, marijuana, and heroin.
Psychoactive drugs
People often consume caffeine when they drink coffee, tea, or cola, or when they eat chocolate. Somewhat mixed results have been found for the extent to which maternal caffeine intake influences an offspring’s development
Caffeine
Heavy drinking by pregnant women can be devastating to their offspring
Alcohol
are a cluster of abnormalities and problems that appear in the offspring of mothers who drink alcohol heavily during pregnancy
Fetal alcohol spectrum disorders (FASD)
The abnormalities include facial deformities and defects of the limbs and heart. Most children with _____ have learning problems and many are below average in intelligence, with some having an intellectual disability
Fetal alcohol spectrum disorders (FASD)
can also adversely influence prenatal development, birth, and postnatal development
Nicotine
(SIDS, also known as crib death)
sudden infant death syndrome
Preterm births and low birth weights, fetal and neonatal deaths, respiratory problems, and sudden infant death syndrome (SIDS, also known as crib death) are all more common among the offspring of mothers who smoked during pregnancy (Zhang & others, 2017). Prenatal smoking has been implicated in as many as 25 percent of infants being born with a low birth weight (Brown & Graves, 2013).
Nicotine
quickly crosses the placenta to reach the fetus
cocaine
exposure during prenatal development is associated with reduced birth weight, length, and head circumference (Gouin & others, 2011).
cocaine
in other studies, prenatal cocaine exposure has been linked to impaired connectivity of the thalamus and prefrontal cortex in ____
newborns
impaired motor development at____ of age
2 years
slower rate of growth through ____ of age
10 yrs
self-regulation problems at age___
12
elevated blood pressure at ____
9
a recent survey found that marijuana use by pregnant women increased from ___ percent in 2002 to ____ in 2014
2.4 %
3.85 percent
a recent survey found that marijuana use by pregnant women increased from 2.4 percent in ___ to 3.85 percent in ____
2002
2014
was related to lower intelligence in children (Goldschmidt & others, 2008). Research reviews concluded that using it during pregnancy alters brain functioning in the fetus
Marijuana
The difficulties include withdrawal symptoms, such as tremors, irritability, abnormal crying, disturbed sleep, and impaired motor control. Many still show behavioral problems at their first birthday, and attention deficits may appear later in development.
Heroin
associated with very severe withdrawal symptoms in newborns
methadone
The most common treatment for heroin addiction
methadone
Teratogen comes from the Greek word??
Tera
The field of study that investigates the causes birth defects is called
teratology
influence both the severity of the damage to an embryo or fetus and the type of defect:
dose
genetic susceptibility
time of exposure
poses another risk to prenatal development
Incompatibility between the mother’s and father’s blood types
are created by differences in the surface structure of red blood cells.
Blood types
One type of difference in the surface of red blood cells creates the familiar blood groups ____
A, B, O, and AB.
A second difference creates what is called ____
Rh-positive and Rh- negative blood
surface marker
Rh-factor
If a surface marker, called the Rh-factor, is present in an individual’s red blood cells, the person is said to be ___
Rh- positive
if the Rh-marker is not present, the person is said to be ____
Rh- negative
If a pregnant woman is Rh-negative and her partner is Rh- positive, the fetus may be ____
Rh-positive
If the fetus’ blood is Rh- positive and the mother’s is Rh-negative, the mother’s immune system may produce antibodies that will attack the fetus.
True or false
True
Some specific hazards to the embryo or fetus include ….
radiation, toxic wastes, and other chemical pollutants
can affect the developing embryo or fetus, especially in the first several weeks after conception, when women do not yet know they are pregnant.
X-ray radiation
are also sources of danger to unborn children.
Environmental pollutants and toxic wastes
However, a routine diagnostic X-ray of a body area other than the abdomen, with the woman’s abdomen protected by a lead apron, is generally considered safe
T or F
True
can produce defects in offspring by crossing the placental barrier, or they can cause damage during birth
Maternal diseases and infections
is one disease that can cause prenatal defects. A recent study found that cardiac defects, pulmonary problems, and microcephaly (a condition in which the baby’s head is significantly smaller and less developed than normal) were among the most common fetal and neonatal outcomes when pregnant women have ____
Rubella (German measles)
(a condition in which the baby’s head is significantly smaller and less developed than normal)
microcephaly
(a sexually transmitted infection) is more damaging later in prenatal development - four months or more after conception. Damage to offspring includes stillbirth, eye lesions (which can cause blindness), skin lesions, and congenital syphilis
Syphilis
(which can cause blindness)
eye lesions
Another infection that has received widespread attention is ____
genital herpes.
Newborns contract this virus when they are delivered through the birth canal of a mother with genital herpes (Sampath, Maduro, & Schillinger, 2017). About one-third of babies delivered through an infected birth canal die; another one-fourth become brain damaged.
genital herpes
also linked to risk for adverse pregnancy outcomes. When a pregnant woman is older than 35, there an increased risk that her child will have Down syndrome (Jaruratanasirikul & others, 2017).
Maternal age
A developing embryo or fetus depends completely on its mother for nutrition, which comes from the mother’s blood
Maternal Diet and Nutrition
When a pregnant woman experiences intense fears, anxieties, and other emotions or negative mood states, physiological changes occur that may affect her fetus
Emotional States and Stress
may also influence the fetus indirectly by increasing the likelihood that the mother will engage in unhealthy behaviors such as taking drugs and receiving poor prenatal care.
A mother’s stress
Men’s exposure to lead, radiation, certain pesticides, and petrochemicals may cause abnormalities in sperm that lead to miscarriage or to diseases such as childhood cancer
Paternal Factors
is linked to impaired male fertility, as well as increased DNA damage, aneuploidy (abnormal number of chromosomes in a cell), and mutations in sperm
tobacco smoking
(abnormal number of chromosomes in a cell)
aneuploidy
Researchers have found that increasing paternal age _____ the success rate of in vitro fertilization and ______ the risk of preterm birth
decreases
increases
a research review concluded that there is an increased risk of spontaneous abortion, autism, and schizophrenic disorders when the father is ____
40 years of age or older
prenatal programs often include ____
comprehensive educational
social
nutritional services
Although prenatal care varies enormously, it usually involves a defined schedule of visits for medical care, which typically includes —
screening for manageable conditions
treatable diseases that can affect the baby or the mother
during pregnancy helps prevent constipation, conditions the body, reduces the likelihood of excessive weight gain, lowers the risk of developing hypertension, improves immune system functioning, and is associated with a more positive mental state, including reduced levels of stress and depression
Exercise
exposure has been linked to impaired connectivity of the thalamus and prefrontal cortex in newborn
cocaine
During this period, neuron spend time moving to the right locations and are starting to become connected.
Prenatal
