Human growth phases
Human growth phases
Prenatal stage three trimesters 9 months from contraception.
- Germinal stage. 0 to 2 weeks
- Fertilization of sperm and ovum.
- Morula created
- Cell division
- Blastocyst
- Confined within glycoprotein shell called zona pellucida.
- Blastocyst reaches uterus at 5th day. Gets implanted.
- Embryonic stage. 3 to 8 weeks
- Gastrulation - created ectoderm endoderm and mesoderm.
- Spinal cord and central nervous system and brain develop.
- 4th week eyes nose ears mouth development heart rate starts pulse.
- Rapid growth cell differentiation happens. Various organs created blood, kidney, nerve cells.
- most critical period smoking alcohol radiation nutrition deficiency be avoided.
- 5th week arms and legs appear.
- 8 week basic organs are developed except sex organs.
- Fetal stage. 9th week.
- Reflexes emerge. Sex organs develop during third month. 12 week.
- Second tri mester heartbeat get stronger, fingernails hair ear and eyelashes develop. Dramatic increase in size
- Lungs develop
- Brain mature by 28 weeks.
- Bones 32
- muscles 36 fully developed
- 40 weeks full development
- Factors influence. Reilly 2017. Wendell 2013 etc.
- •Soci economic, condition. Age of mother. Above 35 potential risk. Behaviour drugs alcohol. Effect of disease like HIV AIDS. Nutrition of mother. Stress in life.
Graph. Length of crown height velocity centimetre/ 4 weeks
Second graph height centimetre start from 16 end with 40.
Postnatal stage.
- Neonatal period first month.
- Infancy second month till end of lactation 3rd year.
- Childhood 3 to 7 years.
- Late childhood 7 to 10 for girls and 7 to 12 for boys.
- Puberty.
- adolescence- 5 to 10 years after puberty.
postnatal period.
- Most rapid growth during infancy. Deciduous dentition.
- motor skills like walking and running develop in first two years and cognitive abilities rapidly develop.
- Language acquisition. 1 to 3 years.
- Gain 400 gram weight every month in first year. Five times birth weight by age of 2.
- Double height in 4 years
- months rolling. Crawling by 10. Baby steps at 1 year. Climbing stairs by 2 or 3.
- Fine motor. Eye coordination at 4 months. Hand mouth coordination 18 months.
- Childhood
- rapidly growing brain requires rich diet in fat protein energy. Learn behaviour. Butt digestive system and dentition still weak.
- 2 kg every year between 3 and 7 thereafter 3kg every year till puberty.
- at 6 permanent teeth begin. brain growth is complete. First permanent molar appears. Full brain capability allows education and social learning.
- Sensory motor and higher cognitive acquisition during critical periods of plasticity. Hesch 2005
- 5 centimetre every year height gain.
- Motor skills. Head lift at 3 months. 8 2 to 5 years for writing skills.