Chapter 3 Flashcards
Birthweight _______ by 4 months and _______ by a year
Doubles; triples
Most 24-month-olds weigh about __ pounds
28
Norm
An average, or standard, calculated from many individuals within a specific group or population.
Percentile
A point on a ranking scale of 0 to 100. The 50th percentile is the midpoint; half of the people in the population being studied rank higher and half rank lower.
failure to thrive
If an infant’s percentile rank falls too low
Newborns sleep about ______ hours a day. Every week brings a few more waking minutes. By 12 months, the norm is ______ hours a day.
15 to 17; 12 to 13
T/F: we know the reason why there are differences in sleep between cultures
False, we don’t know the cause for differences in sleep between cultures
Co-sleeping
A custom in which parents and their children (usually infants) sleep together in the same room.
Bed-sharing
When two or more people sleep in the same bed
Sudden infant death syndrome
A situation in which a seemingly healthy infant, usually between 2 and 6 months old, suddenly stops breathing and dies unexpectedly while asleep.
What did a detailed study in Texas find out about sudden infant death syndrome?
half of all infants who died suddenly and unexpectedly were bed-sharing at the time
Head-sparing
A 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.
Neurons
One of billions of nerve cells in the central nervous system, especially in the brain.
Axons
A fiber that extends from a neuron and transmits electrochemical impulses from that neuron to the dendrites of other neurons.
Dendrites
A fiber that extends from a neuron and receives electrochemical impulses transmitted from other neurons via their axons.
Synapses
The intersection between the axon of one neuron and the dendrites of other neurons.
Nerutransmitters
A brain chemical that carries information from the axon of a sending neuron to the dendrites of a receiving neuron.
Cortex
The outer layers of the brain in humans and other mammals. Most thinking, feeling, and sensing involves the cortex.
Occipital lobe
Back of the brain, where vision is located
Temporal lobes
Sides of the brain, for hearing
Parietal lobe
The top of the brain, includes smell, touch, and spatial understanding
Frontal lobe
The front of the brain, enables people to plan, imagine, coordinate, decide, and create
Prefrontal cortex
The area of the cortex at the very front of the brain that specializes in anticipation, planning, and impulse control.
Limbic system
The parts of the brain that interact to produce emotions, including the amygdala, the hypothalamus, and the hippocampus. Many other parts of the brain also are involved with emotions.
Amygdala
A tiny brain structure that registers emotions, particularly fear and anxiety.
Hippocampus
A brain structure that is a central processor of memory, especially memory for locations.
Hypothalamus
A brain area that responds to the amygdala and the hippocampus to produce hormones that activate other parts of the brain and body.
Cortisol
The primary stress hormone; fluctuations in the body’s cortisol level affect human emotions.
Pituitary
A gland in the brain that responds to a signal from the hypothalamus by producing many hormones, including those that regulate growth and that control other glands, among them the adrenal and sex glands.
Transient exuberance
The great but temporary increase in the number of dendrites that develop in an infant’s brain during the first two years of life.
exuberant overproduction of cells and connections followed by a several yearlong ______ of pathways by massive elimination
sculpting
Experience-expectant growth
Brain functions that require certain basic common experiences (which an infant can be expected to have) in order to develop normally.
Experience-dependent growth
Brain functions that depend on particular, variable experiences and therefore may or may not develop in a particular infant.
T/F: babies need stimulation
True
Shaken baby syndrome
A life-threatening injury that occurs when an infant is forcefully shaken back and forth, a motion that ruptures blood vessels in the brain and breaks neural connections.
Hearing develops during the _____ trimester of pregnancy, as the fetus hears the mother’s heartbeat, digestion, and voice.
Last
T/F: vision is immature at birth
True
Binocular vision
The ability to focus the two eyes in a coordinated manner in order to see one image.
How do babies appreciate what their mothers eat?
prenatally through amniotic fluid, then through breast milk, and finally through smells and spoonfuls of the family dinner.
Motor skills
The learned abilities to move some part of the body, in actions ranging from a large leap to a flicker of the eyelid. (The word motor here refers to movement of muscles.)
Gross motor skills
Physical abilities involving large body movements, such as walking and jumping. (The word gross here means “big.”)
cephalocaudal
Head-down
proximodistal
Center-out
Fine motor skills
Physical abilities involving small body movements, especially of the hands and fingers, such as drawing and picking up a coin. (The word fine here means “small.”)
T/F: some cultures discourage walking
True
When is, and isn’t, an infant’s low height or weight percentile a problem?
It is not a problem if weight and height gain is steady, i.e., if a low percentile continues to be low for that age but is not declining. It becomes a problem if the percentile is very low, such as 5 percent, and the infant appears malnourished.
What is the difference between experience-expectant and experience-dependent growth?
Expectant experiences are universal, needed for normal development; dependent experiences vary by family and culture, shaping infants to function in their community.
What are the reasons for and against bed-sharing?
The reasons for it are closer parent-infant bonds, and less awakening for either parent or baby. The reasons against it is the risk of suffocation, if a parent, pillow, or blanket accidentally impedes breathing of the baby.
How can pruning increase brain potential?
When unused connections disappear, that allows more room for needed new connections.
What is the difference between experience-expectant and experience-dependent growth?
Expectant experiences are universal, needed for normal development; dependent experiences vary by family and culture, shaping infants to function in their community.
How does vision change over the first year?
Vision is very poor at birth but matures rapidly as infants develop the ability to focus, to use both eyes together, to follow moving objects, to see color.
When and why is it important to understand how well an infant hears?
Ideally hearing losses are recognized at birth, as well as later in infancy, because hearing is essential for learning spoken language.
How are taste, smell, and pain affected by the social context?
All the senses are present at birth, but experience refines and adjusts them. For example, infants develop appreciation for whatever tastes they encounter, via milk and then foods.
Why and when do babies crawl and walk?
Infants seek to move as well and soon as they can in order to explore their environment. Crawling typically becomes possible at about & months, walking at a year.
Which fine motor skills develop in infancy?
Mouth skills are usually first, as infants refine sucking and spitting up. Hand and finger skills develop over the early years, from grasping with the whole hand (by 6 months) to using the fingers (about a year).
