Growth and Development Pregnancy Heredity & Genetics Growth & Development

Prenatal Development & Care Fertilization (Conception)  When male sperm meets female egg Only one sperm cell can fertilize an egg Occurs hours after ovulation RESULTS?

Fertilization/Conception Results: Zygote/Blastocyst Hollow ball of cells – implants into uterine wall Embryo Up until 8 th week of pregnancy Name changes of implantation Fetus

Fertilization: Multiple Births Identical Twins (Monozygotic) Single egg fertilized by single sperm Divides form two embryos Shares single placenta Genetically identical- same gender, similar appearance Fraternal Twins (Dizygotic) Two eggs released fertilized by two different sperm cells Different genetic make-up May or May NOT be same gender

Twins

Conjoined Twins Thoraco-omphalopagus Thoracopagus Omphalopagus Parasitic twins Craniopagus Cephalopagus: Syncephalus Cephalothoracopagus Xiphopagus Ischiopagus Omphalo-Ischiopagus Parapagus (dicephalic parapagus) Craniopagus parasiticus Pygopagus Rachipagus Identical twins joined in utero The overall survival rate for conjoined twins is approximately 25%. The condition is more frequently found among females, with a ratio of 3:1

Embryonic Stage Main internal organs develop Nervous system Senses Skin, hair, nails, mouth Major External Body Structures Appear

Early Embryonic Development Three main structures will develop: Amniotic Sac Umbilical Cord Placenta

Amniotic Sac Thin fluid filled membrane that surrounds and protects the developing embryo Insulates embryo from temperature changes

Umbilical Cord Rope like structure that connects embryo and the mother’s placenta

Placenta Thick blood-rich tissue lines wall of uterus during pregnancy Nourishes embryo – provides nutrients Begins forming during 4 th week of pregnancy

Fetal Development Begins at Week 9 and lasts until Birth! In the womb: Fetus grows and gains weight At 7 months fat deposits added under the skin to maintain body heat after birth 9 full months divided until three periods known as: Trimesters.

First Trimester 0-2 weeks Zygote floats freely Spinal cord grows faster than rest of body Brain, ears, arms begin to develop **Heart begins to beat. 3-8 weeks Embryo about 1 inch long Mouth, nostrils, eyelids, hands, fingers, feet, toes begin to form Nervous system responds to stimulus Cardiovascular system fully functional 9-14 weeks Fetus develops human profile Sex organs Eyelids, fingernails, & toenails develop **By 12 weeks makes crying motions and may suck it’s thumb

Second Trimester Weeks **Blinking reflex Body grows Growth of head slows Limbs reach full proportion Eyebrows/eyelashes develop **More active – Grasping, kicking Weeks Fetus can hear conversations Sleeping/Waking Cycle Gains Weight Foot long – weighs little more than Lb. **Can be born at 24 weeks (will need special care)

Third (Final) Trimester Weeks Fetus can use all five senses Passes water from bladder Fetus can dream Baby ready to be born

Birth – Final Weeks of Pregnancy Baby’s head moves to lower part of uterus Mother feels weak – irregular muscle contractions Contractions grow stronger, more regular LABOR

Labor Final Stage of Pregnancy Uterus contracts and pushed baby out

3 Stages of Birth Stage 1 Initial Phase – Fetus position before birth Active Phase – Dilation of cervix (10 cm) Contractions cause cervix to Dilate Dilate - Widen Contractions break amniotic sac AKA Water break

Stage 2- Expulsion of the Fetus Baby passes through birth canal and emerges After the birth, baby cries to clear lungs of amniotic fluid

Stage 3 – Expulsion of Placenta (Afterbirth) Umbilical cord is still attached to placenta Contractions will continue until placenta is pushed from mother’s body Umbilical cord is cut

Importance of Prenatal Care WHO? 1. Obstetrician – doctor specializes in care of a female and her developing child 2. Certified Nurse (Midwife) – advanced practical nurse who specializes in prenatal care and delivering babies

Prenatal Visits Blood tests/pelvic exams Baby viewed on Ultrasound machine Technology using reflection of sound waves

Proper Nutrition during Pregnancy Vitamins and Minerals Calcium (build strong bones, teeth, develops heart rhythm) Protein (forms muscle and tissue) Iron (Make RBC) Vitamin A (eye development, cell and bone growth) Vitamin B (nervous system) **Folic Acid (critical for cell production- deficiencies have been linked to neural disorders ie. Spina bifida)

Spina Bifida Back bone and spinal canal do not close before birth

Nutrition Continued… Caloric intake – Females only need 300 additional calories each day additional Lbs. Excess weight can be health risk Diets can be health risk Caffeine harmful Chocolate, coffee, tea, soda

Tobacco and Pregnancy NO SMOKING!!! – can be harmful Secondhand smoking increases risk of having low birth weight baby Low birth weight baby is leading cause of death for children under 12 months Smoking has caused the following: 30% of low birth weight babies 14% of all premature babies 10% of infant deaths

Alcohol and Pregnancy Alcohol passes quickly from umbilical cord to fetus Alcohol level in fetus’ blood can be higher than mother’s FETAL ALCOHOL SYNDROME (FAS)

FAS- alcohol related birth defects Physical Small Skulls Abnormal facial features Heart defects Mental Mental retardation Learning disabilities Behavior problems Slowed growth

Medicines & Other Drugs Over the counter ONLY with approval Drugs (Illegal) – make mother less able to support pregnancy Consequences Birth defects Premature labor Miscarriage Baby can be born addicted to drug Infant will suffer withdrawal (irritable, cry for hours, tremble, shake, fail to bond with parents)

Environmental Hazards Lead- can lead to miscarriages, LBW, mental disabilities, behavior problems Smog (Air pollution) Radiation – effects fetal growth & causes mental retardation Litter boxes/Cat Litter Feces contains parasite called toxoplasmosis Can result in miscarriages, premature labor Household Chemicals – wear gloves

Complications 1. Miscarriage – spontaneous expulsion of fetus (occurs BEFORE 20 th week of pregnancy) 2. Stillbirth – a dead fetus expelled from body AFTER 20 th week REASONS? Nothing Genetic Abnormally Tobacco, drugs, toxins

Complications continued.. Ectopic Pregnancy – Zygote implants in fallopian tube, abdomen, ovary, cervix… WHY? Fertilized egg can’t pass to the uterus Sometimes because of inflammation developed by STD Main cause of death of female’s in first trimester

Problems Continued… Preeclampsia (AKA Toxemia) Symptoms: High blood pressure Headaches Vision problems Swelling in face, hands, and feet Prevents placenta from getting enough blood Results: LBW Seizures (Eclampsia) Life risks for baby or mother Treatments: Bed rest Blood pressure medicine Having the baby

CDH- - Congenital Diaphragmatic Hernia  Congenital malformation (birth defect) of the diaphragm  Malformation of the diaphragm allows the abdominal organs to push into the proper lung formation.  Occur 1 out of 2,500.  Life threatening

DO NOW: What are examples of traits that are passed onto you from your parents?

Genetics

Heredity Passing of traits from: PARENTS  CHILDREN Examples? Hair color Eye Color Shape of Earlobes

Inherited Traits Environment may influence inherited traits. How? Sun may affect color of skin Sun may affect hair color Nutrition may affect growth

Chromosomes & Genes Chromosomes: Thread-like structures found within nucleus of cell – carry code for inherited traits 46 Chromosomes Arranged in pairs (23) Found inside almost every cell’s nucleus

Chromosomes & Gender First 22 pairs – autosomes 23 rd pair – sex chromosomes Female – XX Male- XY ?? Male

DNA Chemical unit that makes up chromosomes 4 chemical bases that make-up strand Adenine – Thymine Guanine - Cytosine (Deoxyribonucleic Acid)

Genes Basic unit of heredity Genes are sections of the DNA found on the chromosomes (made up of the thousands of bases The order of the arrangement is called Genetic Code Thousands of genes in every cell in your body One gene from each pair is inherited from each parent

So how do we compare to other organisms?

Genetics & Development Everyone has 46 Chromosomes - sex cells have only half (23) When sperm & egg unite, the resulting zygote will have 46. (23 from each parent) So how do we get trillions of cells?

Mitosis Zygote divides (mitosis) multiple times producing trillions of cells that make up human body Each chromosome duplicates itself producing two sets of 46 chromosomes

Genetic Disorders Mutation in inherited gene Defect in gene Typically has little or no effect on person However, can result in defects or health problems Most cannot be cured, can be treated Some are apparent right away

Genetic Disorders Progeria (Hutchinson-Gilford Progeria Syndrome) Undergo advanced aging at an early age Huntington’s Disease Neurological Disorder Passed down through families Nerve cells in parts of the brain begin to waste away Angelman Syndrome Neuro-genetic disorder Severe intellectual and developmental disability Known as “angels” because of their youthful, happy appearance

Dominant vs. Recessive Dominant trait is a genetic trait which will manifest when only one copy of the gene is present Recessive trait will only appear if an organism inherits a copy of the gene from both parents. ** Otherwise, the recessive will remain inactive and the dominant trait will take over.

Dominant and Recessive Traits Punnett Square G – Dominant g – Recessive Examples: Green vs. Brown Eyes Right hand vs. Left Hand Freckles vs. No Freckles

Technologies Amniocentesis – syringe inserted through female’s abdominal wall into amniotic fluid Sample of fluid is drawn Usually performed weeks after fertilization

Technologies Chorionic Villus Sampling (CVS) – small piece of membrane removed from chorion Chorion – layer of tissue develops into placenta Done 8 th week of pregnancy or after birth

Human Genome Project Purpose: International Scientific research project Identify the approx 20-25,000 genes in human DNA Primary goal of determining sequence of chemical base pairs (3 billion sequences) Identify all genes in the human DNA Began Oct declared completed Apr Help us better understand genetic mutations and diseases

Will we be able to alter the way our children look in the future?

Developmental Stages of Humans

Basic Stages of Growth & Development For each stage  Developmental Tasks Needs to occur during a particular stage Occurs so a person can develop toward becoming an adult Age Categories split into stages Scientist: Erik Erikson Erikson’s Stages of Development

Erikson’s Stages Infancy Birth- 1½ years Early Childhood 2nd and 3 rd yrs. of life Childhood 4 th and 5 th years Late Childhood 6 – 11 years. of age Puberty Ages 9-16

Infancy (Birth – 1 ½ years) Fastest period of growth! Developmental Tasks: Eating solid food Beginning to walk Perceiving people as objects Learning to talk Developing trust 13 months

Early Childhood (2 & 3 yrs.) Developmental Tasks Master Walking Learn to climb Push and Pull objects Increase vocabulary Potty training Developing independence Gain sense of Autonomy

Childhood (4 and 5 yrs.) Developmental Tasks Initiate play activities Mimic adults Begin to ask questions Parents foster – children become creative Parents act impatient – could limit child * INITIATIVE

Late Childhood (6 -11 yrs) Experience Major Social Phenomenon Why? – Developmental Tasks: Social Learn to get along with others Learn roles of society Emotional Develop sense of conscience Intellectual Reading, writing, math School

Puberty Beginning of adolescence Males and females are capable or reproduction Physical (Primary & Secondary) Changes Mental Changes

Puberty continued… Physical Primary Sex Characteristics Gametes (Ova & Sperm) Secondary Sex Characteristics Body hair Breast development Muscular Development Deepening of voice

Puberty Continued... Mental Cognition and memory increase Emotional changed- High and low feelings (hormones) Social Changes- Friendships/relationships become more important

Puberty continued… Developmental Tasks Form mature relationships Accept physique Gain emotional independence from parents/adults Development of personal identity

Erik Erikson’s Stages of Development