Download Developmental Stages

1. Pregnancy, Growth, Development and Genetics
A. Prenatal Development & Care
1) Fertilization (Conception)
a. When a male sperm meets a female egg (oocyte/ovum)
b. Only one sperm cell can fertilize an egg.
1} Occurs 12-24 hours after ovulation.
a) Ovulation occurs approximately 11 to 14 days after period starts
2} Fertilization/Conception results in:
a) Zygote
b) Blastocyst
1/ Hollow ball of cells
2/ Implants in the uterine wall
c) Embryo
1/ Formerly the blastocyst
2/ Name changes after implantation
d) Fetus
c. Fertilization: Multiple Births
1} Identical Twins (Monozygotic)
a) Single egg fertilized by a single sperm cell
b) Divides forming two embryos
c) Shares a single placenta
d) Genetically identical, same gender, similar appearance
2} Fraternal Twins (Dizygotic)
a) Two eggs released & fertilized by two sperm cells
b) Different genetic makeup
c) May or may not be the same gender
B. Early Embryonic Development
1) Embryonic Growth
a. Offspring is termed Embryo
1} (after the blastocyst implants)
2} Up until the end of the 8th wk
a) when the basic structural form of the human body is recognizable
b. During this period
1} Amniotic Sac forms
a) Thin fluid-filled membrane that surrounds and protects the
developing embryo
b) It also insulates the embryo from temperature changes
2} Umbilical cord (connecting stalk)
a) Rope-like structure that connects the embryo and the mother’s
placenta.
3} Placenta forms
a) Thick, blood-rich tissue that lines the walls of the uterus during
pregnancy and nourishes the embryo.
b) Begins to form in the 4th wk or pregnancy
c) Does not allow blood to mix between mother and child
d) Provides nutrients
4} Main internal organs develop
a) These arise from three tissue layers formed within embryo:
1/ 1st layer-Ectodermal cells
a/ Both Nervous systems, sense organs, skin, hair, nails, and
mouth
2/ 2nd layer-Mesodermal cells
a/ Blood and blood vessels
b/ internal Reproductive Organs & Kidneys
c/ muscles, connective tissue and bones
3/ 3rd layer-Endodermal Cells
a/ Linings of
1- Respiratory and digestive systems
2- Urinary bladder and urethra
b) Major external body structures appear
C. Fetal Development
1) Fetal Stage begins at the end of the 8th wk and lasts until birth.
2) About nine full months, that is divided into three periods called trimesters.
3) In the womb
a. Fetus grows and gains weight
b. After seven months fat deposits are added under the skin
1} helps maintain body heat after birth
c. Fetus stores nutrients
d. Builds immunity and protection from diseases/infections
4) First Trimester
a. 0-2 weeks
1} zygote floats freely for two days
2} Spinal cord grows faster than the rest of the body.
3} brain, ears, and arms begin developing
4} Heart begins to beat.
b. 3-8 weeks
1} embryo is about one inch long at eight weeks
2} mouth, nostrils, eyelids, hands, fingers, feet, and toes begin to form
3} nervous system can respond to stimuli
a) Stimulus- something that causes a response.
4} cardiovascular system is fully functional
c. 9-14 weeks
1} fetus develops human profile
2} sex organs, eyelids, fingernails and toenails develop
3} by 12 weeks the fetus makes crying motions and may suck it’s thumb
5) Second Trimester
a. 15-20 weeks
1} Can blink it’s eyes
2} body grows
3} growth of head slows
4} limbs reach full proportion
5} eyebrows and eyelashes develop
6} Fetus becomes more active (grasping, kicking, etc.)
b. 21-28 weeks
1} Fetus can hear conversations
2} cycle of waking and sleeping
3} gains weight
4} Fetus is a foot long, weighs a little more than one pound.
5} can be born at 24 weeks
a) will need special care if this occurs
6) Third (final) Trimester
a. 29-40 weeks
1} fetus can use all five senses
2} passes water from the bladder
a) from ingesting amniotic fluid
b) through mouth
3} some fetuses begin to dream
4} Baby weighs 6-9 pounds
5} ready to be born.
D. Birth
1) Final weeks of pregnancy
a. baby’s head moves to the lower part of the uterus
b. mothers feel weak, irregular muscle contractions
c. contractions grow stronger, more regular, and closer together, this is called
labor
1} Labor- final stage of pregnancy. Uterus contracts and pushes the baby
out of the body
2} Pregnancy ends w/ the birth process, labor.
2) Stages of birth
a. Stage 11} Initial phase-fetus position before birth
2} Active phase- dilation of the cervix (10cm)
3} contractions of uterus cause the cervix to dilate
a) Dilate- To widen
4} in 95 percent of pregnancies the baby’s head is resting on the cervix
5} contractions break the amniotic sac that surrounds the baby
a) A.K.A. Water break
b. Stage 2- Expulsion of the fetus
1} When cervix is fully dilated the baby passes through the birth canal
and emerges from the mother’s body.
2} Right after birth the baby cries to clear the lungs of amniotic fluid.
c. Stage 3- expulsion of the placenta (afterbirth)
1} The umbilical cord is still attached to the placenta
2} contractions continue until the placenta is pushed from the mother’s
body
3} umbilical cord is cut.
2. Prenatal Care
A. Prenatal care-
1) steps that a pregnant female can take to provide for her own health and the
health of her baby.
2) this shows that you understand the impact of personal health behaviors of the
body systems.
3) Importance of Prenatal care.
a. One decision is who will provide prenatal care
1} Obstetriciana) a doctor who specializes in the care of a female and her developing
child.
2} A certified nurse (midwife)a) an advanced practical nurse who specializes in prenatal care and
delivering babies.
3} Birthing centera) A facility in which women with low-risk pregnancies can deliver
their babies in a home-like setting.
b. During prenatal visits the female will have a complete physical
1} includes blood tests and pelvic exams
2} purpose- identify problems so they can be corrected or treated ASAP
3} Midwife monitors mother’s weight and blood pressure
4} Baby is viewed with the ultrasound machine
a) Ultrasound
1/ Technology that uses the reflection of sound waves to monitor
the fetus.
2/ A developing fetus can be viewed on a monitor
3/ Doctors can measure how a fetus is growing and which organs
are developing properly.
4/ You can determine a fetuses position
5} Gives parents a chance to ask questions
c. Proper Nutrition During Pregnancy
1} Vitamins and Minerals
a) Calcium
1/ Helps build strong bones, teeth, nerves, and muscles
2/ Develops heart rhythm
b) Protein
1/ Forms muscle and other tissue
c) Iron
1/ Helps in making red blood cells
2/ RBC’s supply oxygen
d) Vitamin A
1/ Aids in cell and bone growth
2/ eye development
e) Vitamin B Complex
1/ Aids in forming the nervous system
f) Folic Acid
1/ Critical for cell production and division
2/ Deficiencies have been linked to neural disorders
a/ Spina bifida
3/ Folic acid is needed to close the tube containing the central
nervous system
4/ Females of childbearing age should consume 400-600
micrograms daily
g) Caloric Intake
1/ Females only need 300 additional calories each day
2/ Professionals suggest gaining 25-35 pounds
3/ Excess weight can be a health risk
4/ Diets can also be a health risk
h) Caffeine can also be harmful to fetus
1/ found in chocolate, coffee, tea and soda
d. Physical activity
1} can be beneficial for mother and fetus
2} should be monitored and managed by a doctor
4) The health of the fetus
a. Tobacco and Pregnancy
1} Smoking can be harmful to the fetus
2} Smoking has caused
a) 30% of low birth weight babies
b) 14% of all premature babies
c) 10% of infant deaths
d) Can affect the child until they are 11 years old
3} Secondhand smoke
a) increases the risk of having a low birth weight baby
b) low birth is the leading cause of death for children under twelve
months
b. Alcohol and Pregnancy
1} consumed alcohol quickly passes from the umbilical cord to the fetus
2} Alcohol level in the fetus’ blood can be higher than that of the
mother’s
3} an elevated alcohol level can result in permanent damage
a) known as Fetal Alcohol Syndrome (FAS)
4} A group of alcohol related birth defects that includes both physical and
mental problems
a) Consequences of FAS
1/ Mental retardation
2/ Learning disabilities
3/ Behavior problems
4/ slowed growth
b) Physical Deformities
1/ Small skulls
2/ abnormal facial features
3/ heart defects
c. Medicines, Other Drugs and Pregnancy
1} Over the counter drugs should be taken with approval of a doctor
2} Drugs (illegal) can make the mother less able to support the pregnancy
3} can also harm fetal development
a) Consequences of use of illegal drugs are
1/ Birth defects
2/ Premature labor
3/ Miscarriage
4/ Baby can be born addicted to the drugs
a/ Infant will suffer withdrawal
b/ May be hypersensitive, irritable, may cry for hours, tremble
and jerk, and may fail to bond with it’s parents
d. Environmental Hazards
1} Lead
a) exposure has caused miscarriages, low birth weight (LBW), mental
disabilities, and behavior problems
2} Smog - Air pollution
a) Linked with birth defects, LBW, Premature birth, Still birth, Infant
death
3} Radiation
a) Effects fetal growth
b) Causes mental retardation
e. Litter Boxes/Cat litter
1} Cat feces contains a parasite that causes a disease called toxoplasmosis
2} Toxoplasmosis can result in miscarriages, premature labor, and health
problems.
3} Pregnant females should wash their hands after petting a cat or wear
gloves.
f. Household chemicals
1} Pregnant females should read the caution, wear gloves, and work in
well-ventilated areas.
3. Complications During Pregnancy
A. Miscarriage1) Spontaneous expulsion of a fetus that occurs
2) Before the twentieth week of a pregnancy.
B. Stillbirth.
1) Stillbirth- A dead fetus expelled from the body after the twentieth week.
C. Reasons for complications
1) Miscarriage or stillbirth doesn’t mean the mother did something wrong
2) Can be caused by genetic abnormality
a. May occur naturally
b. Or could be related to tobacco, drug use, or other toxins
3) Proper prenatal care can reduce the risk
D. Ectopic Pregnancy.
1) Zygote implants in the fallopian tube, the abdomen, the ovary or the cervix.
a. It can occur when the fertilized egg can’t pass to the uterus.
1} Sometimes because of inflammation or scar tissue that has developed
because of an STD.
b. Can’t get the nourishment it needs to grow.
2) Can be a threat to a pregnant female’s life.
a. Main cause of death of females in the first trimester of pregnancy.
E. Preeclampsia (A.K.A. Toxemia)
1) Symptoms include
a. High blood pressure (usually higher than 140/90 mm/Hg)
b. Swelling in hands and face
c. Large amount of proteins in urine.
2) Prevents the placenta from getting enough blood.
3) May result in LBW
4) Treatments include
a. bed rest
b. Blood pressure medicine
c. Having the baby
F. Gestational Diabetes Mellitus
1) 2-5% of pregnant females are diagnosed with Gestational Diabetes Mellitus
(GDM) It usually disappears after the babies birth.
4. Heredity
A. The passing of traits from parents to their children.
1) Some examples are:
a. Hair color
b. Eye color
c. Shape of earlobes.
2) Environment can also influence inherited traits.
a. Example: Poor nutrition may stunt a child’s growth.
B. Chromosomes and Genes.
1) Chromosomes
a. Thread-like structures found within the nucleus of a cell that carry the
codes for inherited traits.
b. There are 46 chromosomes
1} arranged in pairs (23)
2} Found inside almost every cell’s nucleus (gametes have only 23 single
chromosomes).
2) DNA (deoxyribonucleic acid)
a. The chemical unit that makes up chromosomes
b. 4 Chemical bases make up the strands of DNA
1} They are
a) Adenine
b) Thymine
c) Guanine
d) Cytosine
c. These 4 bases can be arranged in many different ways
3) Genes
a. The basic unit of heredity
b. Genes also occur in pairs (found on same chromosome pairs)
c. There are thousands of genes in every cell in your body
1} One gene from each pair is inherited from each parent.
d. Genes are a section of the DNA found on the chromosome
1} Made up of thousands of bases
a) The arrangement of these bases along each DNA strand differs
2} This arrangement of bases gives instructions to the cell
a) To produce a specific product (usually proteins)
3} The order or arrangement of the bases in a gene (section of DNA) is
called the genetic code
C. Genetic code1) By following the code
a. Cells make proteins which help build and maintain body tissue
b. Or they make products your body needs to function
2) Your characteristics are determined by your genetic code.
5. Genetics and Development
A. Everyone has 46 chromosomes while your sex cells have only half (23)
1) When a sperm and egg unite the resulting zygote will have 46,
a. 23 from each parent.
2) A zygote divides (mitosis) many times producing trillions of cells that make
up the human body.
a. Each chromosome duplicates itself producing two sets of 46 chromosomes
b. When the cell divides the chromosomes separate
1} This transfers the same genetic information to the new cell.
B. Dominant and Recessive Genes
1) Produce traits (characteristics of your body).
a. Dominant genes
1} Traits generally appear in offspring when dominant genes are present.
b. Recessive genes
1} Traits only appear when dominant genes aren’t present.
2} This situation is complex because traits that express a quantity or an
extent usually depend on many gene pairs, not just one.
C. Genes and Gender.
1) One pair of chromosomes (#23) determines the gender of an individual
a. If you are female your 23rd pair of chromosomes are XX
b. If you are male you are XY
2) Males determine gender
D. Genetic Disorders
1) Sometimes the genes an individual inherits contain a mutation.
a. Mutation is a defect in a gene
2) Typically this usually has little or no effect on the individual.
3) In some situations
a. Can result in defects or other health problems
4) These defects or problems are Genetic Disorders
a. Caused partly or completely by a defect in genes.
b. Some are apparent right away.
c. Most cannot be cured but can be treated, especially before birth.
5) Two common technologies for finding these defects are
a. Amniocentesis.
1} a procedure in which a syringe is inserted through the female’s
abdominal wall into the amniotic fluid
a) fluid surrounding the developing fetus.
b) Sample of fluid is drawn
2} Usually preformed 16-20 weeks after fertilization
b. Chronic Villi Sampling (CVS)
1} A procedure in which a small piece of membrane is removed from the
chorion.
a) Chorion- A layer of tissue that develops into the placenta.
2} This tissue can be examined for genetic disorders or determine age and
gender.
a) Is done around the eighth week or after a child is born.
1/ For example: Phenylketonuria (PKU) is diagnosed soon after
birth a baby’s diet can be altered to prevent mental retardation.
6) Genetic Counseling.
a. One way that the prevention and control of health problems are influences
by research and medical advances.
b. Genetic counselors can guide families of children with disorders regarding
possible treatment options.
7) Genetic Research to Cure Disease
a. The human genome project has identified approximately 30,000 genes on
the 46 human chromosomes.
b. Gene maps can be used to diagnose genetic disorders.
8) Gene Therapy.
a. Process of inserting normal genes into a human cell to correct genetic
disorders.
9) Genetic Engineering- The practice of placing fragments of DNA from one
organism to another.
a. Many disorders result from the lack of a functioning gene without this
certain substances that the body needs isn’t produced.
b. Examples of Genetic Diseases include:
1} Cystic Fibrosis
2} Various types of cancer.
10) Genetically Engineered Drugs.
a. Genes used to treat disease aren’t directly inserted into human beings.
b. They are placed into other organisms causing them to produce the
substances needed.
1} Also used to produce some vaccines.
11) Human Genome Project (HGP) Purpose
a. To identify all of the genes in human DNA
b. To determine the sequences of the three billion base pairs that make up
human DNA
1} This was announced in June 2000 scientists hope to use this info to
improve diagnosis and treatment for approximately 4,000 human
genetic disorders.
6. Developmental Stages of Humans
A. There are basic stages of growth and development
1) For each stage there are specific developmental tasks that are performed
a. A developmental task is one that
1} Needs to occur during a particular stage
2} In order for the person to continue their growth toward being an adult
b. These tasks occur across age categories
2) Stages were identified by scientists/psychologists
a. Erikson
1} Thought that success in reaching tasks shaped our experiences during
that stage
2} Failure at a stage can be overcome in future stages
b. Erikson’s stages
1} Infancy
a) From birth to one-half years.
b) Fastest period of growth
1/ 3x bodyweight
2/ 2x height
c) Developmental tasks
1/ Eating solid food
2/ Beginning to walk
3/ Perceiving people and objects
4/ Learning to talk
5/ Developing trust
a/ Trust is developed by a parent show of caring
1- Picking the baby up when they cry
2- If this doesn’t happen the baby the baby may develop a
lower level of trust
2} Early Childhood
a) 2nd and 3rd years of life
b) Developmental tasks
1/ Master walking
2/ Learn to climb
3/ Push and pull objects
4/ Increase vocabulary
5/ Potty training
6/ Developing independence (do things on their own)
a/ If accepted by the parents the child will gain a sense of
autonomy
b/ If the parents do everything for the child they will have less
sense of autonomy
3} Childhood
a) 4th and 5th years
b) Developmental tasks
1/ Initiate play activities
2/ Mimic adults and begin to ask questions
a/ If parents foster this behavior children learn initiative
b/ They also learn to be creative and explore new ideas
c/ If parents don’t foster this or act impatient making the child
think this is wrong
1- Could limit the child initiative
4} Late Childhood
a) Ages 6 and 11
b) Experience major social phenomenon
1/ School
c) Developmental Tasks
1/ Growth in the following areas
a/ Social
1- Learn to get along with others
2- Learn roles of society
b/ Emotional
1- Development of conscience
c/ Intellectual
1- Reading
2- Writing
3- calculating
d/ Physical
e/ Cultural
1- Sense of industry (make things)
2/ These develop when the tasks are encouraged by parents
3/ Or may be lacking if they are discouraged
5} Puberty
a) Ages 9-13
b) Beginning of adolescence
1/ Period when males and females are capable of reproduction
2/ Changes are related to the release of hormones
c) Physical changes
1/ Sex characteristics
a/ Primary
1- Gametes (sperm and ova)
2- Sperm are oly produced when puberty starts
3- Ova are present at birth but don’t mature until puberty
2/ Secondary
a/ Body hair (B)
b/ Breast development (F)
c/ Muscular development (M)
d/ Deepening of voice (M)
d) Mental Changes
1/ Brain reaches adult size and weight
2/ Cognition and memory increases
a/ Cognition- process of knowing, includes judgment and
awareness
e) Emotional changes
1/ Can create high and low feelings
2/ Related to hormones
f) Social changes
1/ Friendships and relationships become more important
g) Developmental Tasks
1/ Forming mature relationships
2/ Achieving gender specific roles
3/ Accepting your physique
4/ Gaining emotional independence from parents and adults
5/ Acquiring personal standards that guide behavior
6/ Developing social intelligence (aware of human needs)
7/ Coping with success and failure
8/ Developing conceptual and problem solving skills
9/ Development of Personal Identity
a/ The factors you believe make you unique