Prenatal Development PDF

Class Objectives: At the end of the lesson, students are expected to; - to understand the different stages of prenatal development - describe the developmental stages of the prenatal...

Class Objectives: At the end of the lesson, students are expected to; - to understand the different stages of prenatal development - describe the developmental stages of the prenatal development - to identify the different teratology and hazards to prenatal development SLIDESMANIA.COM  Human life begins at conception -That which is in the mother’s womb is indeed a developing human being. An unborn baby of eight (8) weeks is not essentially different from one of eighteen (18) weeks or twenty-eight (28) weeks. From conception, the zygote, the embryo, and the fetus are undeniably human life. SLIDESMANIA.COM  Biological Beginnings SLIDESMANIA.COM  The Stages of Pre-natal Development SLIDESMANIA.COM  Germinal Period First 2 weeks after conception. This includes the a) creation of the zygote, b) continued cell division, and c) attachment of the zygote to the uterine wall. SLIDESMANIA.COM  The following are the details of development during this period: a) 24 to 30 hours after fertilization- the male (sperm) and female (egg) chromosomes unite b) 36 hours- the fertilized ovum, zygote, divides into two (2) cells c) 48 hours (2 days) 2 cells become 4 cells d) 72 hours (3 days) 4 cells become a small compact ball of 16-32 cells SLIDESMANIA.COM  e) 96 hours (4 days) -hollow ball of 64-128 cells f) 4-5 days -inner cell mass (blastocyst) still free in the uterus g) 6-7 days -blastocyst attaches to the wall of the uterus h) 11-15 days -blastocyst invades into the uterine wall and becomes implanted in it (implantation) SLIDESMANIA.COM SLIDESMANIA.COM  Blastocyst- the inner layer of cells that develops during the germinal period. Trophoblast- the outer layer of cells that develops also during the germinal period, later provides nutrition and support for the embryo. SLIDESMANIA.COM  Embryonic Period (2-8 weeks after conception) in this stage, the name of the mass cell- zygote, become an embryo. SLIDESMANIA.COM  The following development takes place in the embryonic stage: a) cell differentiation b) life-support systems for the embryo develop c) organs appear SLIDESMANIA.COM  Endoderm- the inner layer of the cells, develops into the digestive and respiratory systems. The outer layer is divided into two: Ectoderm- outermost layer which becomes the nervous system, sensory receptors (eyes, ears, nose), and skin parts (nails, hair) Mesoderm- the middle layer which becomes the circulatory, skeletal, muscular, excretory, and reproductive systems. This process of organ formation during the first two months of pre-natal development is called organogenesis. SLIDESMANIA.COM  Respiratory Digestive System System Circulatory System SLIDESMANIA.COM  The three-life support systems of the embryo include; a) placenta- consists of a disk-shaped group of tissues in which small blood vessels from the mother and the offspring intertwine but do not join. b) umbilical cord- contains two arteries and one vein that connects the baby to the placenta. c) amnion- is a bag or an envelope that contains a clear fluid in which developing embryo floats. SLIDESMANIA.COM  Fetal Period ( 2 months to 7 months after conception) growth and development continue dramatically during this period. SLIDESMANIA.COM  a) 3 months after conception- fetus is about 3 inches long and weighs about 1 ounce; fetus has become active, move its arms and legs, opens and closes its mouth, and moves its head, the face, forehead, eyelids, nose chin can now be distinguished and also the upper arms, lower arms, hands, and lower limbs, the genitals can now be identified as male or female. SLIDESMANIA.COM  b) 4 months after conception- the fetus is about 6 inches long and weighs 4-7 ounces, growth spurt occurs in the body’s lower parts; pre-natal reflexes are stronger; mother feels arm and leg movements for the first time. c) 5 months after conception- fetus is about 12 inches long; weighs close to a pound; structure of the skin (fingernails, toenails) have formed; fetus is more active. SLIDESMANIA.COM  d) 6 months after conception- the fetus is about 14 inches long and weighs one and a half pounds; eyes and eyelids are completely formed; a fine layer of hair covers the head; grasping reflex is present and irregular movements occur. e) 7 months after conception- the fetus is about 16 inches long; weighs 3 pounds. f) 8 and 9 months after conception- fetus grows longer and gains substantial weight, about 4 pounds. SLIDESMANIA.COM  Teratology and Hazards to Pre-natal Development SLIDESMANIA.COM  Teratology- is the field that investigates the causes of congenital (birth) defects. A teratogen is that which causes birth defects. It comes from the Greek word “tera” which means “monster” SLIDESMANIA.COM  Clusters of hazards to pre-natal development 1. Prescription and non-prescription drugs 2. Psychoactive drugs 3. Environmental hazards 4. Other maternal factors SLIDESMANIA.COM  Clusters of hazards to pre-natal development 1. Prescription and non-prescription drugs - Antibiotic is an example of a prescription drug that can be harmful. - Example of non-prescription drugs are diet pills, and aspirin- common drugs for relieving minor aches, pains and fever. SLIDESMANIA.COM  Clusters of hazards to pre-natal development 2. Psychoactive drugs - these include nicotine, caffeine, and illegal drugs such as marijuana, cocaine, heroin and cannabis. - Research found that pregnant women who drank more caffeinated coffee were more likely to have preterm deliveries and newborns with lower birthweight. SLIDESMANIA.COM  - Heavy drinking by pregnant women results to the so- called fetal alcohol syndrome (FAS) which is a cluster of abnormalities that appears in the children of mothers who drink alcohol heavily during pregnancy. Abnormalities include; a. Facial deformities b. Defective limbs, face, and heart c. Below average in intelligence d. Mentally retarded - Smoking during pregnancy results to preterm and lower birthweights. SLIDESMANIA.COM  Clusters of hazards to pre-natal development 3. Environmental hazard - these include radiation in jobsites and x-rays, environmental pollutants, toxic wastes, and prolonged exposure to heat in saunas and bath tubs. SLIDESMANIA.COM  Clusters of hazards to pre-natal development 4. Other maternal factors such as; A. Maternal Diseases Rubella (German measles) Syphilis (a sexually transmitted infection) AIDS B. Maternal Diet and Nutrition C. Maternal Age high anxiety and stress, age ( too early or too late, beyond 30) SLIDESMANIA.COM  Neuroscience and Brain Development SLIDESMANIA.COM  Neuroscience and Brain Development Neuroscience, often known as Neural Science, is the study of the Human Nervous System, how the Nervous System works, and how it develops. Neuroscience is an interdisciplinary science that works closely with other disciplines, such as mathematics, linguistics, engineering, computer science, chemistry, philosophy, psychology , and medicine SLIDESMANIA.COM  THREE MAIN GOALS OF NEUROSCIENCE Understand the brain and how it functions Understand and describe how the central nervous system develops and matures over time. Analyze, understand neurological. psychiatric disorders, and discover methods to prevent or cure them SLIDESMANIA.COM  BRAIN DEVELOPMENT Is a sequence of biological processes that lead to the formation of functional neural networks. The protracted process begins about 2 weeks after conception and continues through out childhood adolescence and young adult. A Child's brain develops at a faster rate from birth to age five than at any other period in life. SLIDESMANIA.COM  Brain development that occurs during prenatal months is largely under genetic control, however, experiences can also affect a child’s development. Early brain development has a long-term impact on a child’s learning abilities SLIDESMANIA.COM  90% of brain growth happens before kindergarten at birth, the average baby’s brain is about a quarter of the size of the average brain. Incredibly, it doubles in size in the first year. It keeps growing to about80% of adult size by age 3 and 90% nearly full-grown by age 5. The brain is the command center of the human body. Synaptogenesis - formation of connections between neurons SLIDESMANIA.COM  Brain Connections How brain connection is built? Movements Children develop brain Thinking connections through their Communication everyday experiences. A child's relationship with the adults in their life is the most important influence on their brain development SLIDESMANIA.COM  Factors Affecting Biological and Physical Development 1. HEREDITY Also called inheritance or biologicalinheritance is the passing on of traitsfrom parents to their offspring. GENES A gene is the basic physical andfunctional unit of heredityCan be classified into 1. Recessive (Weak Genes) 2. Dominant (Strong Genes) SLIDESMANIA.COM  2. Environment The environment plays a critical role in the development of children and it represents the sum total of physical and psychological stimulation the child receives. SLIDESMANIA.COM  3. Sex The sex and other physical traits and determined by the combination of: (1)Chromosome and (2) Genes, during fertilization (the union of the two cells, egg, and sperm.) CHROMOSOME Is made up of proteins and DNA organized into genes. Each cell normally contains 23 pairs of chromosomes. SLIDESMANIA.COM  Two (2) types: Autosomes or traits chromosome (22 pairs) Gonosome or sex chromosome (the X and Y) SLIDESMANIA.COM  4. Exercise and Health Proper exercise helps children grow well and reach milestones on time or sooner. Exercise also keeps them healthy and fights off diseases by strengthening the immune system. SLIDESMANIA.COM  5. Hormones Their timely functioning is critical for normal physical growth and development in children. They work slowly, over time, and affect many different processes, including growth SLIDESMANIA.COM  6. Nutrition Malnutrition can cause deficiency diseases that adversely affect the growth and development of children SLIDESMANIA.COM  7. Familial Influence Families have the most profound impact in nurturing a child and determining the ways in which they develop psychologically and socially SLIDESMANIA.COM  8. Geographical Influence Where you live also has a great influence on how even the weather of a place influences children in the form of bodily rhythms, allergies, and other health conditions, your children turn out to be. SLIDESMANIA.COM  9. Socio-Economic Influence The socio-economic status of a family determines the quality of the opportunity a child gets. SLIDESMANIA.COM  10. Learning and Reinforcement Learning involves much more than schooling. It is also concerned with building the child Up mentally, intellectually, emotionally, and socially. SLIDESMANIA.COM