Ch.5 physical development and health. 0 to 3
Integration and differention
As neurons multiply, migrate to their assigned locations, and develop connections, they undergo the complementary process of integration and differentiation Through integration, the neurons that control various groups of muscles coordinate their activities. Through differentiation, Each neuron takes on a specific, specialized structure and function
Sensory capacities: hearing
Auditory discrimination develops rapidly after birth. Even in the womb, fetuses can tell new speech sounds from those they have heard before. -Infants as young as 2 days old were able to recognize a word they heard up to a day earlier. - At 1 month, babies can't distinguish sounds as close as ba and pa -By 11 to 16 weeks, infants are able to both recognize and remember entire sentences after a brief delay. -by 4 months infants brains are showing lateralization for language, as occurs in adults. By this age, the left side of infants brain responds preferentially to speech, especially that of their native language, over other sounds. -Because hearing is a key to language and hearing impairments are the most common cause of speech delays, hearing impairments should be identified as soon as possible. • Hearing loss occurs in 1 to 3 of 1,000 infants
reflex behaviors
Automatic, innate responses to stimulation. • Human babies have an estimated 27 major reflexes, which are present at birth or soon after. • they are controlled by the lower brain centers that govern other involuntary processes, such as breathing and heart rate. • both the presence of reflexes and the disappearance of unneeded reflexes on schedule are signs of neurological development
glial cells (glia)
cells in the nervous system that support, nourish, and protect neurons
Neurons
nerve cells that send and receive information.
brain plasticity
the brain's ability to change, especially during childhood, by reorganizing after damage or by building new pathways based on experience
Cerebrum: Corpus Callosum
- Cerebrum- resembles a walnut, is the largest part of the brain. It is divided into right and left hemispheres, each with specialized functions. • the left hemisphere is the center for language and logical thinking • the right hemisphere processes visual and spatial information, enabling us to read maps or draw. -corpus callosum- a tough band of tissue that joins the two hemispheres together. It is a giant switchboard of fibers connecting the hemispheres and allowing them to share information and coordinate command. •grows dramatically during childhood, reaching adult size by age 10
proximodistal principle
Growth and motor development proceed from the center of the body outward. For example, Babies first develop the ability to use their upper arms and upper legs, then the forearms and forlegs, then hands and feet, and finally fingers and toes
physical growth
Growth is faster in the first few months of life than it ever will be again. Rabid growth rate tapers off during the 2nd and 3rd years. As a baby grows into a toddler, body shape a proportions change too. A 3 year old is slender compared to a chubby potbellied 1 year old. Genes an infant inherits strongly influence whether the child will be tall or short, thin or stocky, or somewhere in between.
cephalocaudal principle
Growth occurs from the top down. Newborns head is disproportionally large. At 1 year the brain is 70% percent of its adult weight, but the rest of the body is only 10 to 20% of adult weight. The head becomes proportionally smaller as the child grows in height and the lower parts of the body develop. Sensory and motor development follow the same principle- infants see objects before they can control their torso and they learn to us the upper parts of the body before the lower parts.
Infant obesity
Having a weight for height in the 95th percentile, has increased in infancy as it ha in all age groups in the United States. At risk for later obesity- Children born to mothers who had a higher pre-pregnancy body mass index or who gained a great deal of weight during the pregnancy were at higher risk, as were infants who weighed a great deal at birth or gained weight quickly as infants
Moro reflex
Reflex in which a newborn strectches out the arms and legs and cries in response to a loud noise or an abrupt change in the environment
primitive reflexes
Reflexes such as sucking, rooting for the nipple, and the moral reflex, are related to instinctive needs for survival and protection.
brain growth
The Brains growth occurs in fits and starts called brain growth spurts. 3 weeks after conception- brain gradually develops from a long hollow tube into a spherical mass of cells. By birth the spinal cord and brain stem are nearly complete. The brain is only about 1/4 - 1/3 of its eventual adult volume. The cerebellum grows fastest during the first year of life By age 3 the typical child's brain weighs 3 1/2 pounds, nearly 90% of its eventual adult weight. The growth of the brain is a life long process fundamental to physical, cognitive, and emotional development.
Nutrition
The importance of good nutrition for infants and toddlers is critical. Normal growth and brain development require the proper mix of vitamins, minerals, calories, and high-quality protein sources. Failure to secure these essential substances can have effects lasting far past the early years in areas as diverse as cognitive development, physical health, work capacity, and earning power. Babies who eat well the first year are smarter, stronger, healthier, and better suited to life's challenges.
Myelination
The process that enables signals to travel faster and more smoothly. Begins about halfway through gestation, Peaks during the first year of life, continues into adolescence, and persist through the third decade of life. Myelination occurs rapidly throughout infancy, accelerating at 12 to 16 months, and then slowly again from 2 to 5 years of age. At 5 years of age, the myelinated white matter volume in the brain is approximately 80% of that found in adults
Sensory capacities: smell and taste
The sense of smell and taste begin to develop in the womb. Flavors of food the mother has consumed are found in amniotic fluid, thus a preference for certain tastes or smells can be developed in utero. Moreover, flavor from foods that the mother eats are also transmitted via breastmilk Taste preferences developed in infancy may last into early childhood; children offered different flavors in early infancy later have less restricted food Preferences. Newborns much prefer sweet tastes to sour, bitter, or salty taste.
Sensory capacities: touch and pain
Touch- The most important sense in infancy. Touch is the first sense to develop; for the first several months it is the most mature sensory system. • by 32 weeks of gestation, all body parts are sensitive to touch, and this sensitivity increases during the first 5 years of life Pain- there is evidence that the capacity for pain emerges sometime in the third trimester of pregnancy. • Newborns can and do feel pain, and they become more sensitive to it during the first few days
Teething
Usually begins around 3 or 4 months, when infants begin grabbing almost everything in sight to put into their mouths, but the first tooth may not actually arrive until sometime between 5 and 9 months, or even later. By the first birthday, babies generally have 6 to 8 teeth By age 2 1/2, they have a mouthful of 20
Sensory capacities: sight
Vision is the least developed sense at birth. Visual perception and the ability to use visual information- identifying caregivers, finding food, avoiding dangers- become more important as infants become more alert and active. Visual acuity at birth is approximately 20/400 but improves rapidly, reaching 20/20 level by 8 months Binocular vision- the use of both eyes to focus, enabling depth and distance perception- usually does not develop until 4 or 5 months Infants show a special affinity for faces. From the very beginning, infants prefer to look at human faces more than almost any other stimuli. Even though their vision is not operating at peak levels, infants are nonetheless able to discriminate between individual faces within hours after birth
malnutrition
Wide spread in many low-income communities and often fatal. Malnutrition is implicated in more than half of deaths of children globally and many children are irreversibly damaged by age 2 Under nourished children are at high risk for stunted growth and poor health and functioning throughout life. Chronic no nutrition is caused by factors such as poverty, low quality foods, poor dietary patterns, contaminated water, unsanitary conditions, insufficient hygiene, inadequate healthcare, and diarrheal diseases and other infections. Approximately 3.1 million children around the world die each year from chronic nonfiction, counting for 45% of all deaths of children under five. World wide 25% of children under five or malnourished.
Breastfeeding
With regard to nutrition, it's almost always best for infants. Should begin immediately after birth and continue for at least 1 year, longer if the mother and baby wish. American academy of pediatrics (AAP) recommends that babies be exclusively breast fed for 6 months. Social factors that make Breastfeeding difficult: -Short or absent postpartum maternity leave -lack of flexible scheduling -inability to take relatively frequent and extended breaks at work to pump milk -lack of privacy Breast feeding is in advisable: - If mother is infected with the acquired immune deficiency syndrome (AIDS) virus or any other infectious illness - if she has untreated active tuberculosis - if she has been exposed to radiation -if she is taking any drug that would not be safe for the baby
Myelin
a fatty substance that helps insulate neurons and speeds the transmission of nerve impulses
Four lobes of the brain
frontal, parietal, occipital, temporal