Ch. 2

Rubella

(German measles) is a viral infection. Women who are infected during the first 20 weeks of pregnancy stand at least a 20% chance of bearing children with birth defects such as deafness, intellectual disabilities, heart disease, or eye problems, including blindness

Proximodistal

(Latin for "near to far")

DES (short for diethylstilbestrol)

A powerful estrogen, has been shown to have caused cervical, vaginal, and testicular cancers in some offspring

Tuner syndrome

A single X sex chromosome. Produce little estrogen

Thalidomide

1960s treatment for insomnia N nausea. Taken during the second month of pregnancy almost invariably (causes birth defects, such as missing or stunted limbs).

Alpha-fetoprotein (AFP) assay

A blood test. linked with fetal neural tube defects—is used to detect neural tube defects such as spina bifida.

Huntington's disease (HD)

A fatal, progressive degenerative disorder and a dominant trait. Physical symptoms include uncontrollable muscle movements

Blastocyst

A few days into the germinal stage, the dividing cell mass takes the form of a fluid-filled ball

Chorionic Villus Sampling

A small syringe is inserted through the vagina into the uterus and sucks out some threadlike projections (villi) from the outer membrane that envelops the amniotic sac and fetus. 9th and 12th week of pregnancy. Greater risk for miscarriage than Amniocentesis.

Cystic fibrosis

Also caused by a recessive gene, is the most common fatal hereditary disease among European Americans. Children with the disease suffer from excessive production of thick mucus that clogs the pancreas and lungs

Pelvic inflammatory disease

An infection of the abdominal region that may have various causes and that may impair fertility

Rh incompatibility

Antibodies produced by the mother are transmitted to a fetus or newborn infant and cause brain damage or death.

Amount of American couples with fertility problems

Approximately one couple in six or seven.

Ova

At birth, women have 300,000 to 400,000 ova in each ovary, although she will only ovulate some 500 of these during her lifetime

Fetal Alcohol Syndrome (FAS)

Babies with FAS are often smaller than normal, and so are their brains.

Surrogate mothers

Bring babies to term for other women who are infertile. Injected with fathers sperm.

Klinefelter Syndrome

Caused by an extra X sex chromosome (an XXY sex chromosome pattern). Less testosterone.

Mesoderm

Develops into the excretory, reproductive, and circulatory systems, the muscles, the skeleton, and the inner layer of the skin

Phenylketonuria

Enzyme disorder. Cannot metabolize an amino acid called phenylalanine, so it builds up in their bodies and impairs the functioning of the central nervous system, resulting in mental retardation, psychological disorders, and physical problems

Endoderm

Forms the digestive and respiratory systems, the liver, and the pancreas.

Germinal stage

From conception to implantation.

How long does the fetal stage last?

From the beginning of the third month until birth.

High doses of vitamins A and D

Have been associated with central nervous system damage, small head size, and heart defects.

Amniocentesis

In this fetal-screening method, the health professional uses a syringe (needle) to withdraw fluid from the amniotic sac.14-16 weeks after conception

Endometriosis

Inflammation of endometrial tissue sloughed off into the abdominal cavity rather than out of the body during menstruation—can obstruct the fallopian tubes, where conception normally takes place

The most common problem in women is

Irregular ovulation or lack of ovulation

Preeclampsia (also called toxemia)

Is a life-threatening disease characterized by (high blood pressure) that may afflict women late in the second or early in the third trimester (Women with toxemia often have premature or undersize babies)

In vitro fertilization (IVF)

Is a method of conception in which ripened ova are removed surgically from the mother and placed in a laboratory dish o The father's sperm are also placed in the dish o One or more ova are fertilized and then injected into the mother's uterus to become implanted

Duchenne muscular dystrophy

Is sex linked. Muscular dystrophy is a chronic disease characterized by a progressive wasting away of the muscles.

Down's syndrome

Is usually caused by an extra chromosome on the 21st pair, resulting in 47 chromosomes. characteristic features: rounded face, a protruding tongue, a broad, flat nose, and a sloping fold of skin over the inner corners of the eyes.

A low sperm count

Lack of sperm—is the most common infertility problem in men

Triple X syndrome

Lower-than-average language skills and poorer memory for recent events

Maternal addiction of heroin or methadone is linked to low birth weight, prematurity, and toxemia fetuses of women who regularly use them can become addicted. Pregnant women who abuse cocaine increase the risk of stillbirth, low birth weight, and birth defects. Infants exposed to cocaine prenatally are often excitable and irritable, or lethargic. pregnant women who take in a good deal of caffeine are more likely than nonusers to have miscarriage or a low-birth-weight baby

Smoking marijuana during pregnancy apparently poses a number of risks for the fetus, including slow growth and low birth weight. The babies of women who regularly used marijuana show increased tremors and startling, suggesting immature development of the nervous system. Pregnant women who smoke are likely to deliver smaller babies than nonsmokers. Their babies are more likely to be stillborn or die soon after birth. are exposed, and people refer to them collectively as pollution Prenatal exposure to heavy metals such as lead, mercury, and zinc may delay mental development at one and two years of age

Embryonic disk

The inner part of the blastocyst has two distinct layers that form a thickened mass of cells.

When do males and females show distinct external genital structures?

Three months after conception.

Ultrasound

Ultrasound waves are reflected by the fetus, and a computer uses the information to generate a picture of the fetus. The picture is termed a sonogram

Preimplantation genetic diagnosis (PGD)

Was developed to detect genetic disorders, but it also reveals the sex of the embryo.

When is infertility applied?

When the couple has failed to conceive on their own for one year.

Cephalocaudal

cephalocaudal (Latin for "head to tail")

Ectoderm

develops into the nervous system, sensory organs, nails, hair, teeth, and outer layer of skin

Over 30 years, these cells are exposed to the environmental slings and arrows of toxic wastes, chemical pollutants, and radiation, thus increasing the risk of chromosomal abnormalities such as Down's syndrome

that the older the father is at conception, the lower a child's score may be on tests of reading skills, reasoning, memory, and concentration