Chapter 2 Vocab

Importance of prenatal care

*medical care received during pregnancy before the baby is born increases the chances of having a healthy baby

The harm done by teratogens is not always simple and straightforward. It depends on the following factors:

-Dose larger doses over longer time periods usually have more negative effects. -Heredity The genetic makeup of the mother and the developing organism plays an important role. Some individuals are better able than others to withstand harmful environments. -Other negative influences. The presence of several negative factors at once, such as additional teratogens, poor nutrition, and lack of medical care, can worsen the impact of a harmful agent. -Age The effects of teratogens vary with the age of the organism at time of exposure. To understand this last idea, think back, once again, to the sensitive period concept introduced in Chapter 1. A sensitive period is a limited time span in which a part of the body or a behavior is biologically prepared to develop rapidly. During that time, it is especially sensitive to its surroundings. If the environment is harmful, then damage occurs, and recovery is difficult and sometimes impossible.

Influence of Maternal Health

-exercise is related to improved fetal cardiovascular function-ing, higher birth weight, and a reduction in risk of certain complications, such as pregnancy-induced maternal diabetes, high blood pressure, and premature birth -nutrition A healthy diet, consisting of a gradual increase in calories that results in a weight gain of 25 to 30 pounds (10 to 13.5 kilograms) helps ensure the health of mother and baby. Prenatal malnutrition can cause serious damage to the central nervous system. The poorer the mother's diet, the greater the loss in brain weight, especially if malnutrition occurs during the third trimester, when the brain is increasing rapidly in size. An inadequate diet during pregnancy can also distort the structure of the liver, kidney, pancreas, and other organs, predisposing the child to later health problems. -emotional stress When women experience severe emotional stress during pregnancy, their babies are at risk for a wide variety of difficulties. Intense anxiety—especially during the first two trimesters—is associated with higher rates of miscarriage, prematurity, low birth weight, physical defects, infant respiratory and digestive illnesses, colic (persistent infant crying), sleep disturbances, and irritability during the child's first three years.Prenatal stressors consistently found to impair later physical and psychological well-being include chronic strain due to poverty; partner abuse; major negative life events such as divorce or death of a family member; disasters such as earthquakes or terrorist attacks; and fears specific to pregnancy and childbirth, including persistent anxiety about the health and survival of the baby and oneself. When we experience fear and anxiety, stress hormones released into our bloodstream—such as cortisol and epinephrine (adrenaline), known as the "flight or fight" hormones—cause us to be "poised for action." Large amounts of blood are sent to parts of the body involved in the defensive response—the brain, the heart, and the muscles in the arms, legs, and trunk. Blood flow to other organs, including the uterus, may be reduced. As a result, the fetus is deprived of a full supply of oxygen and nutrients.

3 face abnormalities characteristics of FASD

-short eyelid openings, which make her eyes look widely spaced -a thin upper lip -a flattened philtrum (the indentation between her nose and upper lip).

By the end of pregnancy, the fetus takes on the beginnings of a personality.Fetal activity is linked to infant temperament. fetal activity is an indicator of healthy neurological development, which fosters adaptability in childhood. The relationships just described, however, are modest. fetuses acquire taste and odor preferences from bathing in and swallowing amniotic fluid (its makeup is influenced by the mother's diet). Between 23 and 30 weeks, the fetus is clearly sensitive to pain, so painkillers should be used in any surgical procedures . Around 29 weeks, fetuses can hear. When presented with a repeated auditory stimulus against the mother's abdomen, they initially react with a rise in heart rate, brain-wave activity, and body movements . Then responsiveness gradually declines, indicating habituation (adaptation) to the sound. If a new auditory stimulus is introduced, heart rate and brain waves recover to a high level, revealing that the fetus recognizes the new sound as distinct from the original stimulus. This indicates that fetuses can remember for at least a brief period. Within the next six weeks, fetuses distinguish the tone and rhythm of different voices and sounds—learning that will serve as a springboard for language development. In various studies, they showed systematic heart-rate and brain-wave changes in response to the mother's voice versus the father's or a stranger's, to their native language (English) versus a foreign language (Mandarin Chinese), and to a simple familiar melody (descending tones) versus an unfamiliar melody (ascending tones)

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Thalidomide

A mild tranquilizer that, taken early in pregnancy, can produce a variety of malformations of the limbs, eyes, ears, and heart.

Placenta

A structure that allows an embryo to be nourished with the mother's blood supply

ultrasound imaging

A technique for examining a fetus in the uterus. High-frequency sound waves echoing off the fetus are used to produce an image of the fetus.

Implantation

At the end of the first week, the blastocyst begins to implant in the uterine lining

Blastocyst

By the fourth day it forms a hollow, fluid-filled ball, called a blastocyst. The inner cells, called the embryonic disk, will become the new organism. The outer cells, or trophoblast, will provide protective covering.

Relationship of maternal age to prenatal and birth complications

Complications increase after age 40, with a sharp rise between 50 and 55 years.

amnion

Membrane that encloses the embryo in protective amniotic fluid which helps keep the temperature of the prenatal world constant and provides a cushion against any jolts caused by the woman's movement.

Women's conditions and prenatal development

Prenatal risk factors include chronic maternal illness, certain maternal infections, toxin exposures and nutritional deficiencies. Risk factors in the perinatal period include pregnancy-related complications, prematurity and low birth weight, and infection exposure during pregnancy or at time of birth.

How is brain development related to fetal capacities and behavior?

Some speculate that a poorly nourished fetus diverts large amounts of blood to the brain, causing organs in the abdomen, such as the liver and kidneys (involved in controlling cholesterol and blood pressure), to be undersized. The result is heightened later risk of heart disease and stroke. In the case of diabetes, inadequate prenatal nutrition may permanently impair the pancreas, leading glucose intolerance to rise as the person ages. Yet another hypothesis is that the malfunctioning placentas of some expectant mothers permit high levels of stress hormones to reach the fetus, which slows fetal growth, increases fetal blood pressure, and promotes excess blood glucose, predisposing the developing person to later disease. During the fetal period, teratogenic dam-age is usually minor. However, organs such as the brain, can still be strongly affected. This can affect the way the child explores his/her environment and over time parent-child interactions, peer relations and opportunities to learn may suffer

Period of the fetus: eleventh week.

The brain and muscles of the rapidly growing fetus are better connected. The fetus can kick, bend its arms, open and close its hands and mouth, and suck its thumb. The yolk sac shrinks as the internal organs assume blood cell production.

Period of the embryo: seventh week.

The embryo's posture is more upright. Body structures—eyes, nose, arms, legs, and internal organs—are more distinct. The embryo now responds to touch and can also move. At less than one inch long and an ounce in weight, it is still too tiny to be felt by the mother.

Germinal period: seventh to ninth day.

The fertilized ovum duplicates at an increasingly rapid rate, forming a hollow ball of cells, or blastocyst, by the fourth day after conception. Between the seventh and ninth day the blastocyst, as shown here magnified thousands of times, burrows into the uterine lining.

Why is the period of the fetus called the "growth and finishing" phase?

The period of the embryo is the most dramatic stage of growth, compared to the period of the zygote and the fetus stage, because during the embryo stage the embryo is just starting to grow and develop everything like their ears, brain, heart, things like that. Once the embryo is in the fetus stage no other parts start to develop, all of the parts that have already been there and they are just finishing developing

Period of the embryo: fourth week

This 4-week-old embryo is only 1⁄4-inch long, but many body structures have begun to form.

Period of the fetus: thirty-sixth week.

This fetus fills the uterus. To nourish it, the umbilical cord and placenta have grown large. Vernix, a cheeselike substance, protects the skin from chapping. The fetus has accumulated fat to aid temperature regulation after birth. In two more weeks, it will be full term.

Period of the fetus: twenty-second week.

This fetus is almost 1 foot long and weighs slightly more than 1 pound. Its movements can be felt readily by the mother and by others who touch her abdomen. If born now, the fetus would have a slim chance of surviving.

Why is the period of the embryo regarded as the most dramatic prenatal period?

This is the most important time of prenatal development because the embryo is developing the foundations for a healthy baby. The blastocyst that implanted in the uterus continues to divide rapidly after implantation. Through a process called differentiation, cells begin to take on different functions.

second month

Tiny buds become arms, legs, fingers, and toes. Internal organs are more distinct: The intestines grow, the heart develops separate chambers, and the liver and spleen take over production of blood cells so that the yolk sac is no longer needed. Changing body proportions cause the embryo's posture to become more upright. During the fifth week, production of neurons (nerve cells that store and transmit information) begins deep inside the neural tube at the astounding pace of more than 250,000 per minute. Once formed, neurons begin traveling along tiny threads to their permanent locations, where they will form the major parts of the brain. By 8 weeks, the testes in the male start to develop and begin secreting the hormone testosterone, which will stimulate differentiation of male internal reproductive organs and the penis and scrotum during the coming month. In the absence of testosterone, female reproductive organs form. By the end of this period, the embryo—about 1 inch long and ounce in weight—can already sense its world. It responds to touch, particularly in the mouth area and on the soles of the feet. And it can move, although its tiny flutters are still too light to be felt by the mother

Rh factor incompatibility

When the mother is Rh-negative (lacks the Rh blood protein) and the father is Rh-positive (has the protein), the baby may inherit the father's Rh-positive blood type. (Because Rh-positive blood is dominant and Rh-negative blood is recessive, the chances are good that a baby will be Rh-positive.) If even a little of a fetus's Rh-positive blood crosses the placenta into the Rh-negative mother's bloodstream, she begins to form antibod-ies to the foreign Rh protein. If these enter the fetus's system, they destroy red blood cells, reducing the oxygen supply to organs and tissues.

methylation

a biochemical process that influences behavior by suppressing gene activity and expression

third trimester

a fetus born early has a chance for survival. The point at which the baby can first survive, called the age of viability, occurs sometime between 22 and 26 weeks. A baby born between the seventh and eighth months, however, usually needs oxygen assistance to breathe. Although the brain's respiratory center is now mature, tiny air sacs in the lungs are not yet ready to inflate and exchange carbon dioxide for oxygen. The brain continues to make great strides. The cerebral cortex, the seat of human intelligence, enlarges. Convolutions and grooves in its surface appear, permitting a dramatic increase in surface area that allows for maximum prenatal brain growth without the full-term baby's head becoming too large to pass through the birth canal. Brain-imaging evidence reveals rapid gains in fetal neural organization: At first, neural connectivity increases within brain areas supporting specific functions, such as vision, movement, language, and integration of information. In the last six weeks, connections begin to form between these areas, yielding primitive brain networks . This pattern of brain growth, which supports coordinated processing of information, will continue after birth. As neural organization improves, the fetus spends more time awake. At 20 weeks, fetal heart rate reveals no periods of alertness. But by 28 weeks, fetuses are awake about 11 percent of the time, a figure that rises to 16 percent just before birth. Between 30 and 34 weeks, fetuses show rhythmic alternations between sleep and wakefulness that gradually increase in organization. Around 36 weeks, synchrony between fetal heart rate and motor activity peaks: A rise in heart rate is usually followed within five seconds by a burst of motor activity . These are clear signs that functioning brain networks have started to take shape in the brain.

amniotic sac

a fluid-filled sac that cushions and protects a developing embryo and fetus in the uterus

fetal alcohol spectrum disorder

a term that encompasses a range of physical, mental, and behavioral outcomes caused by prenatal alcohol exposure Children with FASD are generally given one of the following four diagnoses, which vary in severity: fetal alcohol syndrome (FAS), partial fetal alcohol syndrome (p-FAS), alcohol-related neurodevelopmental disorder (ARND), and alcohol-related birth defects (ARBD)

neural tube

an embryonic structure that gives rise to the central nervous system

gene-environment interaction

because of their genetic makeup, individuals differ in their responsiveness to qualities of the environment

glial cells

cells in the nervous system that support, nourish, and protect neurons

kinship studies

compare the characteristics of family members most common type is between identical twins

situational barriers

difficulty finding a doctor, getting an appointment, and arranging transportation

Zygote

fertilized egg As the zygote moves down the fallopian tube, it duplicates, at first slowly and then more rapidly.

Lanugo

fine, soft hair, especially that which covers the body and limbs of a human fetus or newborn.

umbilical cord

first appears as a primitive body stalk and, during the course of pregnancy, grows to a length of 1 to 3 feet. The umbilical cord contains one large vein that delivers blood loaded with nutrients and two arteries that remove waste products.

amniotic fluid

fluid within the amniotic sac that surrounds and protects the fetus

fetus

from the ninth week to the end of pregnancy, is the longest prenatal period. During this "growth and finishing" phase, the organism increases rapidly in size.

complications an estimated 9 percent of expectant women are diagnosed with gestational diabetes

impaired glucose tolerance that emerges during pregnancy. All diabetic women need careful prenatal monitoring. Extra glucose in the mother's bloodstream causes the fetus to grow larger than average, making pregnancy and birth problems more common. Furthermore, these infants are at increased risk of becoming overweight or obese and developing type 2 diabetes. Maternal high blood glucose also greatly elevates the chances of physical malformations and compromises prenatal brain development: It is linked to poorer attention, memory, and learning in infancy and early childhood

complications experienced by 5 to 10 percent of pregnant women, is preeclampsia (sometimes called toxemia),

in which blood pressure increases sharply and the face, hands, and feet swell in the last half of pregnancy. Untreated preeclampsia can cause brain hemorrhages and kidney failure in expectant mothers, damage to the placenta, and fetal death. Usually, hospitalization, bed rest, and drugs can lower blood pressure to a safe level (Bokslag et al., 2016). If not, the baby must be delivered at once.

Endoderm

innermost germ layer; develops into the linings of the digestive tract and much of the respiratory system

behavioral geneticists

is a field devoted to uncovering the contributions of nature and nurture to this diversity in human traits and abilities.

germinal period

lasts about two weeks, from fertilization and formation of the zygote until the tiny mass of cells drifts down and out of the fallopian tube and attaches itself to the wall of the uterus.

embryo

lasts from implantation through the eighth week of pregnancy. During these brief six weeks, the most rapid prenatal changes take place as the groundwork is laid for all body structures and internal organs.

heritability estimates

measure the extent to which individual differences in complex traits in a specific population are due to genetic factors

second trimester

middle of the second trimester, between 17 and 20 weeks, the new being has grown large enough that the mother can feel its movements. Already, the fetus is remarkably active.A white, cheese like substance called vernix emerges on the skin, protecting it from chapping during the long months spent bathing in the amniotic fluid. White, downy hair called lanugo also appears over the entire body, helping the vernix stick to the skin. At the end of the second trimester, many organs are well-developed. And most of the brain's billions of neurons are in place; few will be produced after this time. However, glial cells, which support and feed the neurons, continue to increase rapidly throughout the remaining months of pregnancy, as well as after birth. Consequently, brain weight increases tenfold from the twentieth week until birth. At the same time, neurons begin forming synapses, or connections, at a rapid pace.

gene-environment correlation

our genes influence the environments to which we are exposed

placenta

permits food and oxygen to reach the developing organism and waste products to be carried away

chorion

protective membrane that surrounds the amnion. From the chorion, tiny fingerlike villi, or blood vessels, emerge.

personal barriers

psychological stress, the demands of taking care of other young children, family crises, and ambivalence about the pregnancy

Teratogens

refers to any environmental agent that causes damage during the prenatal period. The effect of teratogens go beyond immediate physical damage. Some health effects may show up years later. Growing evidence indicates that certain teratogens exert long-term effects epigenetically, by modifying gene expression

Gametes

reproductive cells

Vernix

substance that protects the fetus's skin during development

niche-picking

tendency to actively choose environments that complement our heredity

final three months

the fetus gains more than 5 pounds and grows 7 inches. During the eighth month, lanugo typically is shed. A layer of fat is added to assist with temperature regulation. The fetus also receives antibodies from the mother's blood that protect against illnesses, since the newborn's immune system will not work well until several months after birth. In the last weeks, most fetuses assume an upside-down position, partly because of the shape of the uterus and partly because the head is heavier than the feet. Growth slows, and birth is about to take place.

Mesoderm

the middle layer of an embryo in early development, between the endoderm and ectoderm.

conception

the moment at which a female becomes pregnant

third month

the organs, muscles, and nervous system start to become organized and connected. Touch sensitivity extends to most of the body (Hepper, 2015). When the brain signals, the fetus kicks, bends its arms, forms a fist, curls its toes, turns its head, opens its mouth, and even sucks its thumb, stretches, and yawns. The tiny lungs begin to expand and contract in an early rehearsal of breathing movements. By the twelfth week, the external genitals are well-formed, and the sex of the fetus can be detected with ultrasound (Sadler, 2014). Other finishing touches appear, such as fingernails, toenails, tooth buds, and eyelids. The heartbeat can now be heard through a stethoscope. Prenatal development is some

Ecoderm

the outermost of the three germ layers of an embryo that developes into the epidermis tissues, the nervous system, external sense organs, and the mucous membranes lining the mouth and anus

age of viability

the point at which a fetus can survive if born prematurely

Epigenetics

the relationship between heredity and environment takes place through ongoing, bidirectional exchanges between heredity and all levels of the environment. Genes affect behavior and experiences. Experiences and behavior also affect gene expression. which means development resulting from ongoing, bidirectional exchanges between heredity and all levels of the environment

cerebral cortex

the seat of human intelligence, enlarges. Convolutions and grooves in its surface appear, permitting a dramatic increase in surface area that allows for maximum prenatal brain growth without the full-term baby's head becoming too large to pass through the birth canal. Brain-imaging evidence reveals rapid gains in fetal neural organization: At first, neural connectivity increases within brain areas supporting specific functions, such as vision, movement, language, and integration of information.