Chapter Two: The Start of Life Flashcards
Medulla
Vital in the control of basic functions such as heartbeat and respiration
Part of the brain stem
Nerves that connect spinal cord to higher levels of the brain pass through here
Cerebellum
Helps child maintain balance, control motor behavior, and coordinate eye movements with bodily sensations
Cerebrum
Two hemispheres that become more wrinkled as child develops, coming to show ridges and valleys called fissures
Contributes to human learning, thought, memory, and language
Growth Spurts of the Brain
Formation of neurons completed at birth
1st: during 4th and 5th month of prenatal development; due to formation of neurons
2nd: between 25th week of prenatal development and the end of the 2nd year of life after birth; due to proliferation of dendrites and axon terminals
EEG
Measures brain’s electrical activity
PET
Positron-emission tomography
MRI
Magnetic resonance imaging
Cerebral Cortex
Divided into 2 hemispheres –left/right
Lateralization
Hemispheric specialization
Four Areas of Each Hemisphere
Frontal Lobe
Occipital Lobe
Temporal Lobe
Parietal Lobe
Frontal Lobe
Voluntary thinking and movement
Occipital Libe
Vision functions
Temporal Lobe
Hearing functions
Parietal Lobe
Processing body sensations
Chromosomes
Rod-shaped portions of DNA that are organized in 23 pairs
Genes
The basic unit of genetic information
Deoxyribonucleic Acid (DNA)
The substance that genes are composed of that determines the nature of every cell in the body and how it will function
Monozygotic Twins (MZ)
Twins who are genetically identical
Dizygotic Twins (DZ)
Twins who are produced when two superstar ova are fertilized by two separate sperm at roughly the same time
Homozygous
Inheriting from parents similar genes for a given trait
Heterozygous
Inheriting from parents different forms of a gene for a given trait
Dominant Trait
The one trait that is expressed when two competing traits are present
Recessive Trait
A trait within an organism that is present, but is not expressed
Down Syndrome
a disorder produced by the presence of an extra chromosome on the 21st pair; once referred to as mongolism
characteristic features: rounded face; protruding tongue; broad, flat nose; sloping fold of skin over inner corners of the eyes
deficits in cognitive development and motor development
Klinefelter’s Syndrome (XXY)
1/500 men
a disorder resulting from the presence of an extra X chromosome that produces underdeveloped genitals, extreme height, and enlarged breasts
produces less testosterone
treated with testosterone replacement therapy
Sickle-Cell Anemia
1/10 African Americans
1/20 Latino Americans
Caused by a recessive gene
Red blood cells take on the shape of a sickle and clump together, obstructing small blood vessels and decreasing oxygen supply
Lessened oxygen can impair cognitive skills
Physical problems:
Painful and swollen joints
Jaundice
Potentially fatal conditions such as pneumonia, stroke, and heart and kidney failure
Tay-Sachs Disease
1 in 30 Jewish Americans are carriers
Caused by recessive gene
Causes the central nervous system to degenerate, resulting in death
Commonly found amount children in Jewish families of Eastern European background
Genetic Counseling
The discipline that focuses on helping people deal with issues relating to inherited disorders
Amniocentesis
Done between the 15th and 20th week of pregnancy, this procedure examines a sample of the am optic fluid, which contains fetal cells. Recommend if either parent carries Tay-Sachs, spina bifida, sickle-cell, Down syndrome, muscular dystrophy, or Rh disease
Chorionic Villus Sampling(CVS)
Done at 8 to 11 weeks, either trans -abdominally or trans-cervically. Involves inserting a needle or catheter into the placenta, but staying outside the amniotic sac, and removing 10-15 milligrams of tissue. This is grown in a culture.
Ultra Sound Sonography
Used very-high-frequency sound waves to detect structural abnormalities or multiple pregnancies, measure fetal growth, judge gestational stage, and evaluate uterine abnormalities
Genotype
The underlying combination of genetic material present (but it outwardly visible) in an organism
Phenotype
An observable trait; the trait that is actually seen
Artificial Insemination
Sperm is collected and quick-frozen
Sperm then injected into a woman’s uterus at time of ovulation; addresses low sperm count as well as low sperm motility
Can be used for a woman to get pregnant who does not have a partner
In Vitro Fertilization(IVF)
Ripened ova are surgically removed from the mother and placed in laboratory dish; father’s sperm also placed in dish
One or more ova fertilized and injected into mother’s uterus to become implanted
Used when Fallopian tubes are blocked or father has low sperm motility
A donor can be used
Germinal Stage
The first-and shortest-stage of the prenatal period, which takes place during the first 2 weeks following conception
Embryonic Stage
The period from 2 to 8 weeks following fertilization during which significant growth occurs in the magie organs and body systems
Placenta
A conduit between the mother and fetus, providing nourishment and oxygen via the umbilical cord
Cephalocaudal Principle
The principal that growth follows a pattern that begins with the head and upper body parts and then proceeds down to the rest of the body
Proximodistal Principle
The principle that development proceeds from the center of the body outward
Fetal Stage
The stage that begins at about 8 weeks after conception and continues until birth
Stillbirth
The delivery of a child who is not alive, occurring in fewer than 1 delivery in 100
Teratogen
A factor that produces a birth defect
Critical Period
A specific time during development when a particular event has its greatest consequences and the presence of certain kinds of environmental stimuli are necessary for development to proceed normally
Fetal Alcohol Syndrome(FAS)
A disorder caused by the pregnant mother consuming substantial quantities of alcohol during pregnancy resulting in mental retardation and delayed growth in the child
Genetics
The genetic properties or features of an organism, characteristic, etc.
Polygene
A gene whose individual effect on a phenotype is too small to be observed, but which can act together with others to produce observable variation
Mitosis
A type of cell division that results in two daughter cells each having the same number and kind of chromosome as the parent nucleus, typical of ordinary tissue growth
Mutation
The changing of the structure of a gene, resulting in a versant form that may be transmitted to subsequent generations, caused by the alteration of single base units in DBA, or the deletion, insertion, or rearrangement of larger sections of genes or chromosomes
Meiosis
A type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell, as in the production of gametes and plant spores
Autosome
Any chromosome that is not a sex chromosome
Sex chromosome
A chromosome involved with determining the sex of an organism, typically one of two kinds
Ovulation
Discharge of ova or ovules from the ovary
Allele
One of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome
Carrier
A person or other organism that possesses a particular gene, especially as a single copy whose effect is masked by a dominant allele, so that the associated characteristic (such as a hereditary disease) is not displayed but may be passed to offspring
Multifactorial Transmission
The determination of traits by a combination of both genetic and environmental factors in which a genotype provides a range within which a phenotype may be expressed
Testosterone
A steroid hormone that stimulates development of male secondary sexual characteristics, produced mainly in the testes, but also in the ovaries and adrenal cortex
Triple X Syndrome (XXX)
1/1,000 women
appears normal, but demonstrates lower-than average language skills
poorer memory for recent events
development or external sex organs appears normal
increased incidence of infertility
Sonoembryology
Used to detect abnormalities in he first trimester of pregnancy. Involves high-frequency trans vagina process do digital image processing. I combination with ultrasound, can detect more than 80 percent of all malformations during the second trimester
Fetal Blood Sampling (FBS)
Performed after 18 weeks of pregnancy by collecting a small amount of blood from the umbilical cord for testing. Used to detect Down syndrome and most other chromosome abnormalities in the fetuses of couples go are at increased risk of having an affected child.
Embyroscopy
Examines embryo or fetus during the first 12 weeks of pregnancy by means of fiber-optic endoscope inserted through cervix.can be performed as early as week 5. Access to the fetal circulation may be obtained through the instrument, and visualization of the embryo permits the diagnosis of malformations
Environmental Hazards
Heavy metals such as lead, mercury, and zinc
Exposure to lead related to delayed mental development at 1 and 2 years of age
Consumption of PCB-contaminated fish from Lake Michigan resulted in babies that were smaller and showed poorer motor functioning and memory defects
Radiation has been linked to mental retardation and physical deformity; suggestion to avoid unnecessary x-rays
Adoption
Another way for people to obtain children that results in the formation of loving new families
Surrogate Mothers
Mother who bring baby to term for other women who are infertile
Can be artificially inseminated by partner of infertile woman
Donor IVF
Mother does not produce ova
Ovum from another woman is fertilized and injected into the uterus of the mother-to-be
Turner’s Syndrome (X)
1/2,500 women
affected women have only one X chromosome
external genitals are normal but ovaries develop poorly, producing little estrogen
shorter than average and infertile
cognitive deficits: problems with visual-spacial skills, mathematics, and non-verbal memory
Estrogen
Any of a group of steroid hormones that promote the development and maintenance of female characteristics of the body
Phenylketonuria
1/8,00 children
enzyme disorder transmitted by a recessive gene
cannot metabolize an amino acid called phenylalanine; builds up in body and impairs functioning of the central nervous system (CNS)
results in intellectual disorders, psychological disorders, and physical problems
no cure, but children can be placed on diets low in phenylalanine and develop normally
Huntington’s Disease
1/18,000 Americans
Fatal, progressive degenerative disorder
Dominant trait
Physical symptoms include uncontrollable muscle movements
Psychological symptoms include loss of intellectual functioning and personality change
Onset of HD is delayed until middle adulthood
Possibly half their offspring will develop it
Medicines can deal with some symptoms
Cystic Fibrosis
A hereditary disorder affecting the exocrine glands. It causes the production of abnormally thick mucus, leading to the blockage of pancreatic ducts, intestines, and bronchi and often resulting in respiratory infection
Hemophilia
A medical condition in which the ability of the blood to clot is severely reduced, causing the sufferer to bleed severely from even a slight injury. The condition is typically caused by a hereditary lack of a coagulation factor
Muscular Dystrophy
A hereditary condition marked by progressive weakening and wasting of the muscles
Prenatal
Before birth; during or relating to pregnancy
Miscarriage
The expulsion of a fetus from the womb before it is able to survive independently, especially spontaneously or as a result of accident
Uterus
The organ in the lower body of a woman or female mammal where offspring are conceived and in which they gestate before birth; the womb
Sonogram
A visual image produced from an ultrasound examination
Alpha-Fetoprotein (AFP)
A protein produced by a fetus that is present in amniotic fluid and the bloodstream of the mother. Levels of the protein can be measured to detect certain congenital defects.
Conception
The action of conceiving a child
Endometrium
The mucus membrane lining the uterus, which thickens during the menstrual cycle in preparation for possible implantation of the embryo
Motility
Describes the contractions of the muscles that mix and propel contents on the gastrointestinal (GI) tract
Pelvic inflammatory Disease
Inflammation of the genital tract, accompanied by fever and lower abdominal pain
Endometriosis
A condition resulting from the appearance of endometrial tissue outside the uterus and causing pelvic pain
Blastocyst
A mammalian blastula in which some difference of cells has occurred
Embryonic Disk
Forms the floor of the amniotic cavity
Trophoblast
A layer of tissue on the outside of a mammalian blastula, supplying the embryo with nourishment and later forming a major part of the placenta
Blastula
An animal embryo at the early stages of development when it is a hallow ball of cells
Umbilical Cord
A flexible cordlike structure containing blood vessels and attaching a human fetus to the placenta during gestation
Ectoderm
The outermost later of cells or tissue of an embryo in an early development, or parts derived from this, which include the epidermis and nerve tissue
Neural Tube
A hollow structure from which the brain and spinal cord form. Defects in development can result in congenital abnormalities such as spinal bifida
Endoderm
The internist layer of cells or tissue of an embryo in early development, or parts derived from this, which include the lining of the gut and associated structures
Mesoderm
The middle layer of an embryo in early development, between the endoderm and ectoderm
Androgens
A male sec hormone, such and testosterone
Amniotic Sac
The fluid-filled sac that contains and protects a fetus in the womb
Amniotic Fluid
The fluid surrounding a fetus within the amnion
Syphilis
A chronic bacterial disease that is contracted chiefly by infection during sexual intercourse, but also congenitally by infection of a developing fetus
Congenital
Present from birth (usually a disease or abnormality)
HIV/AIDS
Acquired immunodeficiency syndrome (AIDS) is a chronic potentially life threatening condition caused by the human immunodeficiency virus(HIV). By damaging your immune system, HIV interferes with your body’s ability to fight disease.
Rubella
A contagious viral disease, with symptoms like mild measles. It can cause fetal malformation if contracted in early pregnancy.
Preeclampsia
A condition in pregnancy characterized by high blood pressure, sometimes with fluid retention and proteinuria
Premature
A baby born before the end of the full term of gestation, especially three or more weeks before
Thalidomide
A drug formally used as a sedative, but withdrawn in the early 1960s after it was found to cause congenital malformation or absence of limbs in children whose mothers took the drug during early pregnancy
Progestin
A natural or synthetic steroid hormone, such as progesterone, that maintains pregnancy and prevents further ovulation during pregnancy
Diethylstilbestrol (DES)
A powerful synthetic estrogen used in hormone therapy, as a postcoital contraceptive
