Body Changes
• Average weight: double the birthweight by month 4, triple it by age 1, much of it is fat
• Average height: grow 14 inches from birth to age 2
• These numbers are norms, an average measurement.

Body Changes
Body Size
• Head-sparing- biological mechanism that protects the brain when malnutrition disrupts body growth.
– The brain is the last part of the body to be damaged by malnutrition.
• Percentile- point on a ranking scale of 0 to
100.
– 50 th percentile is the midpoint with ½ the sample being higher and ½ lower.

• Average newborn sleeps 16 hours per day
• Specifics vary due to age, characteristics, and social environment
• Ample sleep correlates with normal brain maturation, learning, emotional regulation, academic success and psychological adjustment

• REM Sleep : Rapid eye movement sleep, dreaming, rapid brain waves
• Slow-wave sleep : quiet sleep, increases at
3-4 months
• Co-sleeping : custom of parents and children sleeping in same room, more common in Asia, Africa and Latin America than in Western cultures

Brain Development
• Neuronthe billions of nerve cells in the central nervous system.
• Cortexthe outer layers of the brain.
• Axon a fiber that extends from a neuron and transmits electrochemical impulses from that neuron to the dendrites of other neurons.

Brain Development
• Dendritea fiber that extends from a neuron and receives electrochemical impulses transmitted from other neurons via their axons.
• Synapsethe intersection between the axon of one neuron and the dendrites of other neurons.
• Neurotransmitter - a brain chemical that carries information from the axon of a sending neuron to the dendrites of a receiving neuron.

Brain Development

• The great but temporary increase in the number of dendrites in an infant’s brain from birth to age 2
• Enables neurons to connect and communicate with other neurons
• This is followed by pruning where unused neurons and misconnected dendrites die

• If it produces too many stress hormones in infants, the brain will not be able to have normal stress responses.
• Occurs in infants who are terrified and experience other forms of stress.
• Can continue to occur when the infant is an adult

Experience-related aspects of brain function:
• Experience-expectant : require basic common experiences in to develop normally (i.e. people who love them)
• Experience-dependent : these happen to some infants but not all, not necessary for brain function (i.e. language baby hears)

Brain Development
• prefrontal cortex: the area for anticipation, planning, and impulse control
• Shaken baby syndromea life-threatening injury occurring when an infant is forcefully shaken back and forth, rupturing blood vessels and breaking neural connections .
• Self-righting - inborn drive to fix a developmental deficit
– All people have self-righting impulses for physical and emotional imbalances.

Sensation and Movement
• SensationThe response of a sensory system (eyes, ears, skin, tongue, nose) when it detects a stimulus.
• PerceptionThe mental processing of sensory information when the brain interprets a sensation.
• Sensory development- typically precedes intellectual and motor development

Sensation and Movement
Hearing develops during the last trimester of pregnancy and is already quite acute at birth; the most advanced of the newborn’s senses.
Vision is the least mature sense at birth.
– Newborns focus only on objects between 4 and 30 inches away.
– Binocular vision , the ability to coordinate the two eyes to see one image, appears at 3 months.

• Function at birth and adapt to social world
• Babies recognize each person’s smell and handling
• Basic Infant Care differs by culture
– Massage important in some cultures
• Infant senses function to help babies join the human family

Sensation and Movement
• Gross motor skillsPhysical abilities involving large body movements, such as walking and jumping.
• Fine motor skillsPhysical abilities involving small body movements, especially of the hands and fingers, such as drawing and picking up a coin.

• Gene differences in different ethnic groups
• Cultural patterns of child rearing affect sensation, perception, and motor skills

Surviving in Good Health
• About 10 billion babies were born 1950-
2010 worldwide
• More than 2 billion died before age 5
• Immunization has saved many people
– The risks of diseases are far greater than the risk from immunization.

Surviving in Good Health

Surviving in Good Health

Surviving in Good Health
Nutrition
• For every infant disease (including SIDS), breast-feeding reduces risk and malnutrition increases it.
• Breastfed babies are less likely to develop allergies, asthma, obesity, and heart disease.
• As the infant gets older, the composition of breast milk adjusts to the baby’s changing nutritional needs.

• Protein-calorie : when not enough food of any kind is consumed
• Stunting : being too short for your age due to severe and chronic malnutrition
• Wasting : being very underweight due to malnutrition

• Marasmus : severe malnutrition during infancy where child stops growing, tissues waste away and then usually dies
• Kwashiorkor : disease of chronic malnutrition during childhood where child becomes more likely to get other diseases such as measles, diarrhea and influenza