Major Motor Milestones

Major Motor Milestones Major Motor Milestones: Motor development for infants is relatively constant and linear from individual to individual Children are variable and therefore have this range in which children typically accomplish certain milestones - Motor Development: Nature vs. nurture debate (whether it is genetic or environmental) Things that suggest nature is: Twins begin walking on the same day typically Children around the world start developing certain motor function skills at around the same age Environmental factors can alter this as well, such as the support system or the lack thereof (i.e. diapers cause babies to begin walking at a later date). Culture can also play a key role in motor development Gross motor skills refer to larger muscles, such as those in the legs, while fine motor skills refer to smaller muscles, such as those in the fingers Larger muscles tend to develop before the smaller muscles 1. Neonatal Reflexes: Reflexes are automatic and involuntary motor responses that allow us to interact with the world Neonatal reflexes are those present in newborns that typically go away over time, these include the: Rooting reflex which refers to the fact if you stroke a baby’s cheek, the involuntarily turn their face toward that stimulus 1. 2. (important for orienting the nip for some good ‘ol milk) → disappears over the first few weeks of life 2. Babinski reflex which describes how the baby will curl and uncurl its toes when the bottom of the foot is stroked → disappears by the time the baby is 12 months old (1 year old) 3. Moro reflex which is kind of a startle reaction (i.e. a loud noise or sudden change in the orientation of the baby’s head) will cause the baby to throw its arms back, arch its back, and bring its arms back toward one another → disappears at about 4-6 months of age 4. Tonic neck reflex which describes how when a baby’s head is turned to the side, the arm on that side will straighten and the other one will bend → disappears at about 6 months of age 5. Galant reflex describes how when the skin on one side of the baby’s back is stroked, the baby will tend to move or swing to that side → disappears at about 6 months of age 6. Palmar grasp reflex describes how a baby will close their hands around any object that touches their hands and can actually grip pretty hard → disappears at about 3-4 months of age 7. Sucking reflex describes how a baby will suck on anything that touches its mouth → disappears at about 3-4 months 8. Stepping reflex describes how if you pick a baby up and place it on a surface, they will move their feet as if they are trying to walk → disappears at about 2 months 9. Swimming reflex describes how if a baby is placed in water, they move their arms and legs around in a swimming motion and involuntarily hold their breaths → disappears at about 6 months of age Although most of these reflexes are pretty much useless in today’s society, they are important indicators to see if there is something wrong in the development of a baby Also, the reappearance of neonatal reflex in adulthood can signify that there might be a serious medical problem Physical Development in Adolescence: Adolescence is the period of transition between childhood and adulthood Brain Changes During Adolescence: The prefrontal cortex is further developed during adolescence and even the limbic system (such as the amygdala and the hypothalamus) Myelination also increases during adolescence, which helps explain why adolescents are faster at processing information than children (myelin helps increase the speed of action potential propagation down the axon) Extra Notes: A tetragon is a substance or environmental factor that can disrupt normal fetal development (i.e. alcohol) Cross-sectional design is a type of observational study that analyzes data from a population, or a representative subset, at a specific point in time, and takes place once (i.e. examining two children of different ages at the same time) Case study design is a research approach that is used to generate an in-depth, multi-faceted understanding of a complex issue in its real-life context Trisomy X is associated with an XXX genotype Turner Syndrome is associated with an XO genotype (one X chromosome is missing or partially missing) Klinefelter Syndrome is an XXY genotype (a boy has an extra X chromosome) Axon myelination occurs during the second trimester Girls begin to menstruate at around the age of 12-13 (although physical changes begin around age 10-11)