Prenatal Development: The Beginning of Behavior: Prenatal Development: The Beginning of Behavior Prenatal Development: Talk about GROWTH!: Prenatal Development: Talk about GROWTH! Characterized by rapid changes! Most dramatic gains in height & weight of the entire lifespan . Microscopic cell to a 20 inch neonate (newborn) in just 9 months! Weight at birth is a BILLION times heavier than at conception Prenatal Development: Prenatal Development Divided into 3 periods (stages) Germinal stage Embryonic stage Fetal stage Germinal Stage: Germinal Stage Length of stage (period): Conception to 2 weeks Conception: Conception A single sperm cell (male) penetrates the outer coating of the egg (female) and fuses to form one fertilized cell. Your most fortunate of moments! Out of the 200 million sperm and 5000 eggs ‘you’ won the race. Zygote: Zygote The first cell of a new organism Union of sperm and egg Germinal Stage: Germinal Stage Key characteristics of stage: Zygote separates into groups of cells according to what they will become. A mass of cells is produced. Cell Division: Cell Division Embryonic Stage: Embryonic Stage Length of stage (period): From 2 weeks to about 2 months (8 weeks) after conception Embryonic Stage: Embryonic Stage Key characteristics of stage: The major organ systems differentiate. Brain, heart, lungs, etc. Growth follows 2 general principles: Cephalocaudal Development: Cephalocaudal Development “Head to tail” Development proceeds from the head to the foot. Brain develops early = further development Proximodistal Development:: Proximodistal Development: “Near to far” Development proceeds from the central axis (midline) to the extremities (distal areas). Spinal cord 1 st , then heart, lungs, etc. Embryonic Stage [cont.]: Embryonic Stage [cont.] 4 th week – primitive heartbeat, .01 in. long (grain of rice) Placenta – exchange of nutrients (but sometimes harmful substances too) Embryo at about 6 weeks: Notice the large neural tube and the formation of the heart and other internal organs.:
Embryo at about 6 weeks: Notice the large neural tube and the formation of the heart and other internal organs.
TERATOGENS: TERATOGENS Non-genetic chemicals or agents that can cause harm to the embryo if ingested or contracted by the mother. The pass through the placenta Fetal Alcohol Syndrome (FAS) Physical Abnormalities of FAS: Physical Abnormalities of FAS A Very Real Disorder!: A Very Real Disorder! A Major Form of Brain Damage!: A Major Form of Brain Damage! FAS Signs and Symptoms: FAS Signs and Symptoms KidsHealth : FAS FAS Stats: FAS Stats Affects 1 in every 750 infants annually in U.S. Now the leading cause of mental retardation in the U.S.! (exceeding Spina Bifida & Downs Syndrome) Only one that is preventable FAS and ADHD? Fetal Alcohol Effect: Fetal Alcohol Effect Affects 40,000 newborns annually in U.S. Less severe effect of moderate drinking Not all symptoms of FAS, but learning disabilities or behavioral problems PowerPoint Presentation: By 7 weeks, the baby has grown into an embryo about the size of a raspberry and has a tiny beating heart . He'll be growing very fast in the next few weeks. (2.5 million brain cells per minute) Genetic code forms (XY or XX) Y = androgens PowerPoint Presentation: 24 7 weeks – Facial features are visible, including a mouth and tongue. The eyes have a retina and lens. The major muscle system is developed and the unborn child moves as if practicing. The child has its own blood type, distinct from the mother's. PowerPoint Presentation: The baby is now about the size of a kidney bean and is constantly moving and shifting. He/she has distinct, slightly webbed fingers . Fetal Stage: Fetal Stage Length of stage (period): From about 9 weeks until birth (after about 38 weeks). Fetal Stage: Fetal Stage Key characteristics of stage: Continued development in size, complexity, & capacity for independent life. Major organ systems, extremities, movement, reflexes PowerPoint Presentation: By now the baby is about 2 inches long -- the size of a lime . His skin is still transparent, but his face is beginning to look more human . PowerPoint Presentation: The baby at 12 weeks: notice the webbing on the fingers, with the digits still fused PowerPoint Presentation: Fetus at 12 weeks Fully-formed brain Vocal chords complete Occasional silent cry Can feel pain Thumb-sucking Eyelids remain shut until 7 th month to protect delicate optical nerve fibers PowerPoint Presentation: 14 weeks – Muscles lengthen and become organized. The mother will soon start feeling the first flutters of the unborn child kicking and moving within. 15 weeks – The fetus has an adult's taste buds and may be able to savor the mother's meals. Foods the mother eats can affect movement of the baby PowerPoint Presentation: Fetus at 4 months or about 16 weeks Face is fully developed and A downy hair covers the skin. Face is fully formed. Eyes are fully formed but not yet functional. PowerPoint Presentation: 16 weeks – Five and a half inches tall and only six to 1- ounces in weight Eyebrows, eyelashes and fine hair appear. The child can grasp with his hands, suck her thumb, kick, or even somersault. PowerPoint Presentation: 24 weeks – Seen here at six months, the unborn child is covered with a fine, downy hair called lanugo. Its tender skin is protected by a waxy substance called vernix. Some of this substance may still be on the child's skin at birth at which time it will be quickly absorbed. The child practices breathing by inhaling amnionic fluid into developing lungs. PowerPoint Presentation: By now, the baby weighs about 2¼ pounds and is nearly 15 inches long. His body fat is beginning to form in preparation for life outside the womb. Eyes open PowerPoint Presentation: The baby may have hair on his head now. He’s probably turned head-down in preparation for birth. He may weigh almost 4 pounds . The fetus sleeps 90-95% of the day with REM sleep dominating the sleep cycle. PowerPoint Presentation: At nine months, the average baby is more than 18 inches long and nearly 7 pounds, but babies vary widely in size at this point. Umbilical cord is almost 2 ft. long! Check out this site:: Check out this site: www.babycenter.com/ fetaldevelopment