Chapter 3: Conception and Prenatal development Flashcards
Prenatal Stage of Development
period that begins with conception and ends with birth of newborn infant
Factors with enormous influence before conception:
Genetic issues, what kind of father/mother would they be, what are their parents like
Progesterone
Hormone secreted by ovaries which stimulates the endometrium (lining of uterus) to prepare for arrival of fertilized egg
Ovulation
14 days later, egg makes way to surface of ovary and breaks through ovary wall
Pregnancy
occurs when the egg is successfully implanted into the uterus
Alcohol effects in males
Reduces sperm count; erectile dysfunction, premature ejaculation
Marijuana effects in males
marijuana’s ingredient hits sperm cells and causes a frenzied swimming activity, causing sperm cells to tire themselves out, cant make the swim to the uterus
Fertilization
the penetration of the egg by sperm; takes place in the fallopian tubes
implantation
the fertilized egg lodges itself into the uterus
Ovarian reserve
the number of remaining viable eggs
Testicles
almond shaped glands found inside a sec
Scrotum
the sac that holds the testicles, cools them
Vagina
receives erect penis
Cervix
extension of uterus; barrier for negative substances that would come in from vagina to uterus; secretes mucus
Mucus
Protective mechanism that is thick throughout most of the cycle, resists sperm cells from coming through; hormones thin out the mucus during ovulation
Cervical hostility
begins when cervical mucus does not thin out; is a hormonal problem, resists sperm cells from reaching uterus
Description of Uterus
Size of clenched fist; very muscular organ; muscles needed to surround, hold a baby, and contract to push baby out
Endometrium
cellular lining of the uterus
What percent of fertilized eggs do not implant into the wall of the uterus?
50%
When does the endometrium thicken?
1 week after ovulation
Endometriosis
a buildup in the fallopian tubes of endometrial cells from the uterus; the cells will reproduce there, clogging the system; one of the leading causes of infertility in women
Bacterial Infections in relation to Female Infertility
infection can break down endometrial tissue, leading to infertility
Conception vs pregnancy
the egg becomes fertilized vs the fertilized egg implants itself into endometrial wall
Polycystic Ovary Syndrome
second major cause of female infertility; the surface of the ovary becomes overwhelmed by cysts which causes irregularity in menstrual periods and interferes with normal process of ovulation
Fallopian Tubes
Located on both sides of the uterus; interior lining of tubes secretes a fluid that hydrates the egg; lining has muscles that contract and cause the cilia to brisk egg and move it along tubes
Tubal Pregnancy (ectopic pregnancy)
fertilized egg gets stuck in fallopian tube, zygote divides and gets bigger and bigger inside the tube; becomes lethal quickly; causes bleeding and hemorrhaging, undetected may lead to infertility but may not show pain
Sexually Transmitted Diseases
May completely cause infertility; many cause discharge that may be easily noticed
Ovaries
Fully form when baby is born; contains all the eggs a girl will ever have; eggs die over time, the rest are released menstruation
Follicle Stimulating Hormone (FSH)
secreted by pituitary gland; stimulates ovaries to ripen eggs; there is 1 dominant egg that will outed
Luteinizing Hormone (LH)
just before ovulating, there is a spike in LH that actually causes ovulation;
Cysts
naturally exist on ovaries everytime you ovulate
ovarian cancer
one of the leading causes of death in females; difficult to detect, may be fatal
Menstrual Cycle
sequence and orchestration of events of reproductive functioning of females
Birth control pill
made of synthetic hormones: estrogen and progesteone; designed to prevent ovulation, creates cervical hostility
Viable Time period egg to become fertilized
24 hours once you ovulate
Follicular Phase
Varies; basal body temp 1/2 degree cooler than luteal; FSH during early part of cycle, stimulating ovaries to ripen eggs
Luteal Phase
body temp goes up 1/2 degree after ovulation; increaase in progesterone, less estradiol: LH is cause of ovulation
Spotting
dominant egg may ripen faster than normal; not influenced by menstrual cycle
How long does it take to make a baby
266 days to 38 weeks
Post Mature babies
Born a few weeks after the due date; placenta is getting old and may starve the baby of oxygen
Premature Babies
born weeks or months early; babies can survive after 26 weeks; generally have many problems
3 Periods of Prenatal Development
Period of the Ovum, Embryo, Fetus
Period of the Ovum (zygote)
first 2 weeks of prenatal development; cells begin to divide at very rapid rate and cells differentiate into distinct layers that will form organ
Period of the Embryo
begins at the end of the second week and extends to the end of the 8th week following conception; all major organ systems are structurally formed except the genitals
Period of the Fetus
3rd and final stage, 9th week - birth
Neural Tube Disorders
occur when blastocyst doesnt successfully fuse to form brain and spinal cord
Spinal Bifida
spine is exposed outside body
Which nutrient may reduce risk of neural tube defects?
Folic acid
Period of the Embryo - details
layers of cells differentiate and each layer is pre-determined to form certain organs; at end of 8th week, baby is 1 inch long; 3.5 weeks after conception, heart beats for the first time
Umbilical Cord
tube containing two arteries and one vein which is pressurized to prevent tangling
placenta
organ that sustains the baby by allowing oxygen and nutrients from the mother’s blood to cross a semi-permeable membrane to the baby; the 2 blood supplies dont actually mix
Rubella Virus
attacked the babies’ optic nerves through placenta
Effects of Thalidomide
babies are born with flipper-like appendages in place of the arms or legs
When does baby have fully functioning immune system?
6 months later
Teratogens
agents that are known to enter the biological system of the embryo and fetus and negatively influence development
Effects of Cigarette Smoke
1/5 of women who smoke, smoke throughout their pregnancy; higher rates of miscarriage, still born, disease
Fetal Growth Reduction
baby may be born 1/2 pound lighter
Effects of Alcohol on Fetus
Ethanol goes right across placenta membrane; stays in high concentration for days, baby has not developed liver to filter alcohol; destroys nerve cells; has negative effect on migration of neurons
Fetal Alcohol Spectrum Disorder (FASD)
takes many forms, because of mother’s alcohol intake; leading cause of preventable intellectual deficiency
Heroin or methadone effects
baby will be addicted to the drug, will experience neonatal abstinence syndrome; babies may be preterm and at low birth weight
Neonatal Abstinence Syndrome
pattern of problems that can be life-threatening; symptoms are variable, but often include tremors, seizures, vomiting, and fevers
Cocaine effects
babies may experience enormous pressure on cardiovascular system; generally irritable, easily over-stimulated, and are disorganized with caregivers
What is 2nd choice of drug during pregnancy?
Meth
Methamphetamine Effects
babies likely to be born as low birthing small-for-gestational age, and with reduced head circumference; may display higher rates of ADHD and aggressive behaviors
Herpes
causes painful genital sores in adults; is transmissible to fetus only when sores are present in vagina when baby is directly contacted with maternal secretions during delivery; antiviral treatment of mother can reduce rate of transmission
CMV
Second Common form of herpes virus; highly infectious, may resemble slight cold
CMV effects on baby
May hide in system and affect baby; infants suffer intellectual disability, hearing loss, and psychomotor problems later in life; most common cause of transmission of disease from mother to newborn
HIV/AIDS
AIDS is progressive weakening of immune system by HIV
HIV/AIDS effects on baby
transmission is in uterus during birth process or breastfeeding; 25-35% rate; infants suffer frequent infection, diarrhea, fail to thrive or gain weight; may have brain damage
Protease Inhibitors
May reduce transmission of HIV/AIDs to baby if treated aggressively
Toxoplasmosis
Infection caused by a parasite found in intestines of infected cats and birds, some raw meats, and from vegetables that contain soil residue
Toxoplasmosis effects on baby
miscarriage, still birth, or death of baby soon after birth
Mercury
industrial pollutant that worked its way into food chain
Toluene
Highly addictive chemical found in paint, glue, cleaning solution
Effects of toluene
reduced birth weight structural abnormalities similar to FASD
Phthalates
chemical agents in many industrial and cosmetic products that are readily absorbed through human skin
Effects of phthalates
abnormalities in genital development in boys at 1 year
Prenatal care
approach a mother and professionals take to ensure her well-being and fetus’s well being during delivery
Heredity
Genetic Transmission of characteristics from parent to offspring
Cells
Biological units that are enormously complex in function and structure
Chromosomes
rod-like structures found in nucleus; 23 pairs of chromosomes, 46 total; one from mother one from father
DNA
makes up chromosomes, 2 strands; arranged in double helix structure
Genes
smaller units that make up each DNA thread; provide blueprints for biological expression of physical structures and traits
Genome
collection of genes inherited across all 23 pairs of chromosomes
Mitosis
body cells duplicate themselves; generates all cells of the body except sex cells
Meiosis
process by which sex cells are produced
Genetic diversity
division of chromosomes in 1st phase of meiosis ensures this
Crossing over
segments of genes may be exchanged between chromosomes
Name of X-chromosome
Gymnosperm
Name of Y-chromosome
Andosperm
Genotype
genetic material from mother blends with genetic material from father to create 1st living cell of unique human being
Phenotype
observable expression of these traits
reaction range
variation of phenotypic expression for given train
opportunity structures
favorable environmental events and experiences that are uniquely designed to profit from some potentiality present in one’s genotype
Gene regulation
individual genes are turned on or off to accomplish a variety of outcomes
Two forms of Gene regulation:
differentiation of body cells early in development; epigenetic changes throughout development
Epigenesis
genes are switched on or off by exposure of cells to specific effects of environment
Recessive Diseases
PKU, Tay-Sachs Disease, Sickle-cell disease
PKU - Phenylketonuria
metabolic disorder where child fails to produce enzyme needed to convert amino acid phenylalanine into harmless substance; without that substance, phenylalanine builds up and destroys CNS
Tay Sachs Disease
child is unable to produce certain enzyme necessary for fat metabolism, causing fatty aids to build up in brain, liver, and spleen; dominant among Jews
Sickle-cell disease
Mostly affects African americans; paired recessive alleles produce abnormal form of hemoglobin, distorting disk-like shape of normal blood cell into sickle shape; clogs blood vessels
Sex-linked inhertiance
genetic transmission of traits and diseases by mechanism of 23rd pair of chromosomes, particularly X
Hemophilia
maladaptive sex-linked trait; inability of blood to clot, leads to internal bleeding, may result in deformity or death
Trisomy
when you have an extra chromosome, something happens during meiosis
Down Syndrone
offspring has extra chromosome, 21st pair does not separate;IQ typically less than 50, varied degrees of intellectual disability; slow motor movement, impaired speech, symptoms increase with age; probability increases with age of mother
Physical traits of down syndrome
broad, flat face with slanted eyes and elongated fold of eyelid; heart defects
Fragile X Syndrome
alcohol is major cause; results from mutation of particular gene located at long arms of X chromosome on 23rd pair; extra chromosomal material; mutation can be inherited; males more affected; one of the largest causes of intellectual disability
Genetic counselor
professional whose trained in transmission of genetic disease and traits and trained in the counseling that’s necessary
Prenatal testing
child that could be born, counselor counsels couple already pregnant and empowers couple if they have to get help for their baby
ultrasound
makes use of very high frequency sound waves to form an electronic “picture” of the fetus
Sonogram
an electronic picture of the fetus
Amniocentesis
insert hollow needle into abdomen of mother, clip off piece of amniotic fluid that contains cells and DNA, can determine if baby has any genetic disorders
Age of viability
26 weeks into pregnancy
Chorionic Villus Sampling (CVS)
insert tube into vagina, dilate cervix, come in contact with developing placenta, suction off piece and remove for DNA testing
Congenital disorders
disorders that are present at birth
