THE FIRST TWO YEARS: BISOCIAL DEVELOPMENT - Chapter 5
I. Physical Growth and Health
A. Size and Shape
1. Average North American baby: 7+ lbs., 20 inches
2. First weight gain is fat, then muscle, bone, and organs
3. Proportions: head < ` 1/8; Legs < ` = ;parts that grew slowly prenatally grow faster now
B. Preventative Medicine
1. In history measles, whooping cough, SIDS main cause of death
2. Immunizations, knowledge has increased survival
II. Brain Growth and Development
A. Connections in the Brain
1. Definitions
Neurons: nerve cell of the Central Nervous System, most are in the brain
Axons: single nerve fiber that extends from a neuron and transmits impulses from that neuron to the dendrites of other neurons (one)
Dendrites: nerve fibers that extend from a neuron and receive the impulses ransmitted from other neurons via their axons (numerous)
Synapse: point at which the axon of one neuron meets the dendrites of another neuron
Neurotransmitters: brain chemical that carries information across the synaptic gap between neurons
Cortex: outer layer of the brain, about an 1/8 inch thick; involved with voluntary, cognitive aspects (perception, thinking)
Transient Exuberance: great increase in the number of neurons, dendrites, and synapses that occurs in an infant's brain over the first 2 years of life
Myelination: process in which axons are coated with myelin, a fatty substance that speeds communication between neurons
Binocular Vision: ability to use both eyes together to focus on a single object
2. Neurons communicate by sending an electrical impulse through axon`dendrites`synapse`new neuron
3. When born, we have 100 billion neurons, with very few synapses; growth is great in first months, and density has increased fivefold by age
2
4. Myelination allows for an increase in neurological control of motor functions and sensory abilities
B. Brain Growth and Brain Function
1. Different areas of the brain grow at different rates
2. Frontal lobe is involved with self-control and self-regulation which are not apparent at birth
C. The Role of Experience in Brain Development
1. Experience plays a big role in the development of neurons
2. Not sure what extent of consequences may be, there is different speculations
III. Motor Skills
Developmental Biodynamics: maturation of the developing person's ability to move through, and with, the environment, by means of crawling, running,
grasping and throwing.
1. Definitions
Reflexes: involuntary physical responses to stimuli
Breathing Reflex: a reflex that ensures an adequate supply of oxygen and the discharge of carbon dioxide by causing the individual to inhale and
exhale
Sucking Reflex: a reflex that causes newborns to suck anything that touches their lips
Rooting Reflex: a reflex that helps babies find a nipple by causing them to turn their heads towards anything that brushes against their cheeks and to attempt to suck it
2. The breathing reflex begins before the umbilical cord is cut, and includes things such as hiccups, sneezing and thrashing
3. Reflexes that maintain body temperature are things suck as shivering, tucking their legs in and pushing blankets
B. Gross Motor Skills
1. Definitions
Gross Motor Skills: physical sills involving larger body movements such as waving the arms, walking, and jumping
Toddler: a child, usually between the ages of 1 and 2, who has just begun to master the art of walking
2. Moving arms and legs`wiggling on bellies`creeping`crawling`climbing`walking
C. Fine Motor Skills
1. Definitions
Fine Motor Skills: physical skills involving small body movements, especially with the hand and fingers, such as picking up a coin or drawing
2. By 6 months a baby should be able to successful grab and hold on to objects
3. After grabbing, babies begin to explore by fingering, holding, and tasting.
D. Variations and Ethnic Differences in Timing
1. Definitions
Norm: a standard, or average, derived or developed for a specified group population; what is normal may not be what is ideal
2. Norms vary from group to group and place to place
3. Inheritance and environmental factors play a role in development
IV. Sensory and Perceptual Capacities
Sensation: the response of a sensory system when it detects a stimulus; people are not necessarily aware of sensations
Perception: the mental processing of sensory information
A. Vision
1. At birth, vision is least developed; distance vision is blurry
2. Binocular vision, color, depth perception, tracking improves weekly
B. Hearing
1. Babies are very sensitive to noise
2. Definitions
Habituation: process of becoming so familiar with a particular stimulus that it no longer elicits the physiological responses it did when it was
originally experienced
Otitis Media: a middle-ear infection that can impair hearing temporarily and therefore can impede language development and socialization if it continues too long in the first years of life
3. Infants can distinguish between speech sounds of any language
C. Taste, Smell and Touch
1. Infants can distinguish tastes except for salty
2. Sense of smell well developed, infants choose sent of mother
3. Touch is very acute, infants use this to examine objects
V. Nutrition
A. The Ideal Diet
1. Infants consume their nutrients in liquid form; breast milk is the best
B. Nutritional Problems
1. Definitions
Protein-Calorie Malnutrition: a nutritional problem that results when a person does not consume enough nourishment to survive
Marasmus: a disease that afflicts young infants suffering from severe malnutrition; growth stops, body tissues waste away, and death may eventually occur
Kwashiorkor: a disease resulting from a protein deficiency in children; the symptoms include thinning hair and bloating of the legs, face and abdomen
2. Primary cause of malnutrition in poorer countries is lack of breast feeding
3. Undernourishment can cause stunt neural growth which can cause in the long run and underdevelopment intellectually and physically