psych 306 week 2

stages of pregnancy

(1) the period of the zygote, (2) the period of the embryo (3) the period of the fetus.

umbilical cord,

- The placenta is connected to the developing organism - which 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.

variables with tetrogens

1) dose: larger doses over longer time periods usually have more negative effects. 2)Heredity: . Some individuals are better able than others to withstand harmful environments. 3)other negative influences: The presence of several negative factors at once, such as addi- tional teratogens, poor nutrition, and lack of medical care, can worsen the impact of a single harmful agent 4)Age: The effects of teratogens vary with the age of the organism at time of exposure. To understand this last idea, think of the sensitive period concept

what does alcohol do to a baby

1)First, it interferes with production and migration of neurons in the primitive neural tube. 2) the body uses large quantities of oxygen to metabolize alcohol. A pregnant woman's heavy drinking draws away oxygen that the developing organism needs for cell growth.

active correlation

As children extend their experiences beyond the immediate family and are given the freedom to make more choices, they actively seek environ- ments that fit with their genetic tendencies. The well-coordinated, muscular child spends more time at after-school sports, the musically talented youngster joins the school orchestra and practices his violin, and the intellectually curious child is a familiar patron at her local library.

week 7 of pregnancy

At 7 weeks, 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 (Nelson, 2011). Once formed, neurons begin traveling along tiny threads to their permanent loca- tions, where they will form the major parts of the brain.

ectoderm becomes

At first, the nervous system develops fastest. The ectoderm folds over to form the neural tube, or primitive spinal cord. - At 31⁄2 weeks, the top swells to form the brain. While the nervous system is developing, the heart begins to pump blood, and muscles, backbone, ribs, and digestive tract appear. At the end of the first month, the curled embryo—only 1⁄4 inch long—consists of millions of organized groups of cells with specific functions

placenta

By bringing the mother's and the embryo's blood close together, the placenta permits food and oxygen to reach the developing organism and waste products to be carrier -. A membrane forms that allows these substances to be exchanged but prevents the mother's and the embryo's blood from mixing directly

chorion

By the end of the second week, cells of the trophoblast form another protective membrane—the chorion, which surrounds the amnion. From the chorion, tiny fingerlike villi, or blood vessels, emerge. - As these villi burrow into the uterine wall, a spe- cial organ called the placenta starts to develop.

The Second Trimester

By the middle of the second trimester, between 17 and 20 weeks, the new being has grown large enough that the mother can feel its movements. A white, cheeselike substance called vernix covers the skin, protecting it from chapping during the long months spent in the amniotic fluid. White, downy hair called lanugo also covers the entire body, helping the vernix stick to the skin.

smoking during pregnancy

The best-known effect of smoking during the prenatal period is low birth weight. But the likelihood of other serious consequences, such as miscarriage, prematurity, cleft lip and palate, impaired heart rate and breathing during sleep, infant death, and asthma and cancer later in childhood, also increases -hen a baby of a smoking mother appears to be born in good physical condition, slight behavioral abnormalities may threaten the child's development. - This reduces the transfer of nutrients, so the fetus gains weight poorly. Also, nicotine raises the concentration of carbon monoxide in the bloodstreams of both mother and fetus. Carbon monoxide displaces oxygen from red blood cells, damaging the central nervous system and slowing body growth in the fetuses of laboratory animals

The Third Trimester

The brain continues to make great strides. The cerebral cortex, the seat of human intel- ligence, 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. As neural connectivity - The third trimester also brings greater responsiveness to external stimulation.

structures inside the blastocyst

The cells on the inside of the blastocyst, called the embryonic disk, will become the new organism; the thin outer ring of cells, termed the trophoblast, will become the struc- tures that provide protective covering and nourishment.

second month (embryonic period)

The eyes, ears, nose, jaw, and neck form. 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 pro- portions cause the embryo's posture to become more upright.

period of the fetus

The period of the 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, especially from the ninth to the twentieth week.

age of viability,

The point at which the baby can first survive, called the age of viability, occurs some- time between 22 and 26 week

evocative correlation

The responses children evoke from others are influenced by the child's heredity, and these responses strengthen the child's original style. For example, an active, friendly baby is likely to receive more social stimulation than a passive, quiet infant.

niche picking

This tendency to actively choose environ- ments that complement our heredity - Niche-picking explains why pairs of identical twins reared apart during childhood and later reunited may find, to their surprise, that they have similar hobbies, food preferences, and vocations—a

lanugo

White, downy hair also covers the entire body, helping the vernix stick to the skin.

FASD

a term that encompasses a range of physical, mental, and behavioral outcomes caused by pre- natal alcohol exposure - Even when provided with enriched diets, FAS babies fail to catch up in physical size during infancy or childhood. Mental impairment associated with all three FASD diagnoses is also permanent

period of the zygote

a) lasts about two weeks, from fertilization until the tiny mass of cells drifts down and out of the fallopian tube and attaches itself to the wall of the uterus. b) The zygote's first cell duplication is long and drawn out; it is not complete until about 30 hours after conception c) By the fourth day, 60 to 70 cells exist that form a hollow, fluid-filled ball called a blastocyst

amnion

amnion, that encloses the developing organism in amniotic fluid, which helps keep the temperature of the prenatal world constant and provides a cush- ion against any jolts caused by the woman's movement.

period of zygote and tetrogens

before implantation, teratogens rarely have any impact. If they do, the tiny mass of cells is usually so damaged that it dies.

implantation

between the 7th and 9th day. - The blastocyst burrows deep into the uterine lining where, surrounded by the woman's nourishing blood, it starts to grow I -

p-FAS

characterized by (a) two of the three facial abnormalities just mentioned and (b) brain injury, again evident in at least three areas of impaired functioning. Mothers of children with p-FAS generally drank alcohol in smaller quantities, and children's defects vary with the timing and length of alcohol exposure. F

vernix

covers the skin, protecting it from chapping during the long months spent in the amniotic fluid

FAS

distinguished by (a) slow physical growth, (b) a pattern of three facial abnormalities (short eyelid openings; a thin upper lip; a smooth or flat- tened philtrum, or indentation running from the bottom of the nose to the center of the upper lip), and (c) brain injury, evident in a small head and impairment in at least three areas of functioning—for example, memory, language and communication, attention span and activity level (overactivity), planning and reasoning, motor coordination, or social skills. O

yolk sac

emerges that produces blood cells until the developing liver, spleen, and bone marrow are mature enough to take over this function

Alcohol related neurodevelopment disorder (ARND)

in which at least three areas of mental functioning are impaired, despite typical physical growth and absence of facial abnormalities. Again, prenatal alcohol exposure, though confirmed, is less pervasive than in FAS

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 surround- ings. If the environment is harmful, then damage occurs, and recovery is difficult and sometimes impossible.

embryonic period and tetrogen

is the time when serious defects are most likely to occur because the foundations for all body parts are being laid down

period of the 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.

gene-enviorment correlation

our genes influence the environments to which we are exposed. two kinds: 1) passive 2) evocative

early cell duplication in female orgrans

page 88 diagram

tetrogen

refers to any environmental agent that causes damage during the pre- natal period. -e effects of teratogens go beyond immediate physical damage. Some health outcomes are delayed and may not show up for decades. Furthermore, psychological consequences may occur indirectly, as a result of physical damage.

corpus luteum,

spot where female eggs travel from - secretes hormones that prepare the lining of the uterus to receive a fertilized ovum. If pregnancy does not occur, the corpus luteum shrinks, and the lining of the uterus is discarded two weeks later with menstruation.

fetal period and tetrogen

tera- togenic damage is usually minor. However, organs such as the brain, ears, eyes, teeth, and genitals can still be strongly affected.

passive correlation

the child has no control over it - Early on, parents provide environments influenced by their own heredity. For example, parents who are good athletes emphasize outdoor activities and enroll their children in swimming and gym- nastics. Besides being exposed to an "athletic environment," the children may have inherited their parents' athletic ability. As a result, they are likely to become good athletes for both genetic and environmental reasons.

last half of the first month (embryonic period)

three layers form: (1) the ectoderm, which will become the nervous system and skin; (2) the mesoderm, from which will develop the muscles, skeleton, circulatory system, and other internal organs; and (3) the endoderm, which will become the digestive system, lungs, urinary tract, and glands.

diethylstilbestrol (DES),

was widely prescribed between 1945 and 1970 to prevent miscarriages. As daughters of these mothers reached adolescence and young adulthood, they showed unusually high rates of cancer of the vagina, malformations of the uterus, and infertility. -When they tried to have children, their pregnancies more often resulted in prematurity, low birth weight, and miscarriage than those of non-DES-exposed women. Young men showed an increased risk of genital abnormalities and cancer of the testes (

canalization

—the tendency of heredity to restrict the develop- ment of some characteristics to just one or a few outcomes. - A behavior that is strongly canalized develops similarly in a wide range of environments; only strong environmental forces can change it - For example, infant perceptual and motor devel- opment seems to be strongly canalized because all normal human babies even- tually roll over, reach for objects, sit up, crawl, and walk. It takes extreme conditions to modify these behaviors or cause them not to appear.