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