Chapter 5 - First Two Years Biosocial Flashcards
Multilevel framework means we can…
look at many levels
Two main division of the NS
1) Central NS: consist of the brain and spinal
cord
2) Peripheral NS: all parts of the NS that are
outside the body skill and spinal column
Central NS
consist of the brain and spinal
Peripheral NS
all parts of the NS that are outside the body skill and spinal column (somatic NS and autonomic NS)
What are the peripheral NS’s 2 components?
1) Somatic Nervous System: Part of the NS that interacts with the environment
• Afferent: Carry sensory signals from body to CNS
• Efferent: Carry motor signals from CNS to body
2) The Autonomic NS: influences the function of internal organs
Somatic Nervous System
Part of the NS that interacts with the environment
Afferent (Somatic Nervous System)
Carry sensory signals from body to CNS
Efferent (Somatic Nervous System)
Carry motor signals from CNS to body
The Autonomic NS
influences the function of internal organs
Cerebral Hemispheres
The right and left halves of the brain
Gyrus
A ridged or raised portion of the cerebral cortex
Sulcus
A furrow (narrow groove) of the cerebral cortex
Cerebral Cortex
The outer covering of the cerebral hemispheres which consists largely of nerve cell bodies and their branches
White Matter
A component of the central nervous system and under the cortex, consists mostly of myelinated axons
Gray Matter
Areas of brain that are mostly cell bodies and have no myelin
What lobe is most susceptible to damage?
Frontal lobe
Cerebellum
A part of the brain at the back of the skull in vertebrates that is responsible for moving and timing
Hypothalamus
Located below the thalamus and above the brian stem, responsible for motivation i.e. sex eating sleeping drugs
Corpus callosum
Bundle of neural fibres below cortex, main system that allows hemispheres to communicate
Corpus Callosotomy
a surgical procedure to control generalized seizures by cutting the corpus callosum
Why are teens so bad at making good decisions and think bad stuff is cool?
Their frontal lobe develops last, so their self regulation, problem solving, goal setting and social cognition are not quite developed yet
What is the frontal lobe responsible for?
self regulation, problem solving, goal setting and social cognition
What is the parietal lobe responsible for?
sensory motor perception and spatial abilities
What is the occipital lobe responsible for?
vision and perception
What is the temporal lobe responsible for?
hearing, language, memory and social emotional function
What grows the fastest? Brain weight, height or weight?
Brain weight
Brain growth chart
20 weeks gestation - 100 grams Birth - 400 grams 18 month - 800 grams 3 years - 1100 grams Adult - 1300-1400 grams
The brain can add up to ___ to ___ new neurons per minute
250,000 – 500,000
Neuron
A nerve cell of the central nervous system. Most neurons are in the brain
How many neuron connections does an infant have by age 3?
~1000 trillion connections
Dendrites
the branched projections of a neuron that are the input zone for receiving information from other neurons
Dendritic Spines
outgrowth from a dendrite that increases the dendrites surface area and is the usual point of contact
Soma
cell body, contains cell nucleus. May receive synaptic connections
Axon
a single extension leads away from the soma and transmits electrical signals away from the cell body
Axon Terminals
swelling at the end of axons (looks like a club) by which axons make synaptic contacts
What do neurons do?
Neurons collect signals from several sources, integrate and transform information, and distributes information to other cells
Four Structural Divisions of the nervous system?
Input Zone
Integration Zone
Conducting Zone
Output Zone
Input Zone
The part of a neuron that receives information, from other neurons or from specialized sensory structures. Usually corresponds to the cell’s dendrites
Integration Zone
The part of the neuron that initiates nerve electrical activity. Usually corresponds to axon hillock (there isn’t only just one neuron that fires or doesn’t, it’s all integrated)
Conducting Zone
The part of the neuron over which the nerve’s electrical signal may be actively propagated. Usually corresponds to cell’s axon
Output Zone
The part of the neuron, usually corresponding to the axon terminals, at which the cell sends information to another cell
Types of neuron shapes?
Bipolar
Multipolar
Unipolar
3 Types of Neurons in the CNS
Sensory: to bring information to the brain (somatosensory)
Interneurons: to associate sensory and motor activity
Motor: to carry information out of the brain and spinal cord to the body’s muscles
How Does the Developing Brain Become Aware, Learn, Think,?
-Overproduction of neurons and neuronal connections
-Selective reduction of neurons and connections
-Periods of intense branching and connecting followed by reduction in neurons

Synaptic Pruning
process of synapse elimination that occurs between early childhood and the onset of puberty
Why is synaptic pruning useful?
Because it narrows your axons to your specific environment, there is no clutter.
Anatomical studies of brain development show
- White mater increases from child- to adulthood
- Grey mater increases over the first 8 years of life then decreases and thins with development
Are there regional differences in white matte development?
No
Regional differences in grey mater:
– Primary sensory/motor areas develop first
– Frontal and superior temporal develop last
* Frontal lobes continue until adolescence
Genes form neurons, connections among major brain regions and then the environment…
refines the connections; enhancing some connections while eliminating others
Brain development is ___ dependent
activity/experience
Neural circuits used over and over strengthen, those that are not used are dropped resulting in?
Synaptic pruning
Transient Exuberance
The great increase in the number of neurons, dendrites, and synapses that occurs in an infant’s brain over the first two years of life
Two types of experience-related aspects of brain development:
1) Experience-Expectant:Refers to brain function that require basic common experiences (which infant is expected to have) in order to grow. These experiences MUST happen for normal brain maturation to occur and they almost always happen. The brain expects them and uses them for growth. i.e. blindfolding someone so their vision doesn’t develop
2) Experience-Dependent: Refers to brain functions that depend on particular, and variable, experiences in order to grow. These MIGHT happen. If they do happen, one brain will differ from another. i.e. extreme neglect resulting in language, it can still be learned later but not really that much
Experience dependent synapse formation happens in what order?
Sensory pathways (vision/hearing) Language Higher cognitive function
What happened with the child without reading difficulties and the child with?
Language area was lit up for normal reader while child with reading difficulties had other parts of the brain lighting up. After specialized reading instruction, the child with reading difficulties was more similar to the child with no reading difficulties
Infants don’t ___ on anything in particular
focus
Till about age one ___ is the primary way humans learn about objects
taste
Sensation
The response of a sensory system when it detects a stimulus
Perception
The mental processing of sensory information
Hearing
- Hearing is acute at birth
- Certain sounds trigger reflexes
- Sudden noises startle newborns
- Rhythmic sounds sooth them and put them to sleep
- The first days of life infants turn their heads towards sound
- They soon connect sight and sound with accuracy
Seeing
• At birth vision is the least mature
• The infant eyes are sensitive to bright light even though
the eyes open in mid-pregnancy
• Newborns are “legally blind” they can only see objects
4” – 30” away (distance from nipple to eyes)
Over time infants become responsive to whose touch it is and what it communicates
true
Early sensation seems to have two goals:
• Social interaction
– To respond to familiar caregivers
• Comfort
– To be soothed amid the disturbances of infant life (crapped pants, hungry, want to turn but cant)
Reflex
A reflex is an involuntary response to a particular stimulus. Almost always occurs in reaction to a particular stimulus. Newborns have many reflexes, some of which disappear with maturation
Infants have dozens of reflexes, what 3 sets are critical for survival?
» that maintain oxygen supply
» that maintain constant body temperature
» that manage feeding
Motor Skill
the learned ability to move some part of the body, from a large leap to a flicker of the eyelid (motor refers to movement of muscles; the abilities needed to move and control the body)
Gross Motor Skills
physical abilities involving large body movements (gross meaning “big”) i.e. walking or jumping
Walking progress
- from reflexive,
- to hesitant
- to adult-supported stepping
- to a smooth coordinated gait (pattern of movement of the limbs)
What are the three factors combine to allow toddlers to walk?
– muscle strength
– brain maturation within the motor cortex
– practices
Fine Motor Skills
physical abilities involving small body movements, especially of the hands and fingers (fine in this text means “small”) i.e. drawing or picking up a coin
Ethnic Variation
- healthy infants develop skills in the same sequence
* they vary in the age at which they acquire them
Walking, when grouped by ethnicity:
- Generally African American are ahead of Hispanic Americans
- Hispanic American are ahead of European American
- Internationally the earliest walkers are in Uganda
- The latest walkers are in France
Genes are a ___ part of most ethnic differences
small
Cultural patterns of child rearing can affect…
sensation, perception, and motor skills
Milestones of Physical Development Gross and Fine Body Movement
1-3 months
- wiggle arms and legs; try to lift head while on stomach
- propel backwards while on stomach
- Grasp reflex
- Prefer patterns, curved lines, human faces – especially mom’s right after birth
Favorite color of toddlers?
red, black and white
Milestones of Physical Development Gross and Fine Body Movement
3-4 Months
- Coordinate limb movement
- Precise grasping (palmer) (grasping feet and toys etc.)
Milestones of Physical Development Gross and Fine Body Movement
6 Months
- Move in a particular direction
- Sit without support
- Visual depth perception of infants is similar to adults
- Visual Cliff Experiment (Gibson and Walk, 1960)
–> Increase heart rate at 2-3 months
Milestones of Physical Development Gross and Fine Body Movement
7 Months
- Stand with support
- Hand preference first appears
Milestones of Physical Development Gross and Fine Body Movement
8-10 Months
- Crawling
- Pincer Grasp (grasp using thumb and forefinger)
- Distinguish faces of different humans
Milestones of Physical Development Gross and Fine Body Movement
11 Months
- Standing alone
- Pincer grasp (grasp using thumb and forefinger) perfected, can pick up small objects like marbles
Milestones of Physical Development Gross and Fine Body Movement
12 Months
- Walking alone
Milestones of Physical Development Gross and Fine Body Movement
14 Months
- Able to lift and stack large items (e.g. building two cube tower)
- Binocularvisionfullydeveloped
Milestones of Physical Development Gross and Fine Body Movement
16 Months
- Walking up the steps (one foot at a time)
- Drawing
Milestones of Physical Development Gross and Fine Body Movement
24 Months
- Jumping in place
- Hold a cup and drink without spilling
_ billion children were born between 1950 – 2005
_ billion died before age 5
8, 2.
Baby deaths could be twice this if not for:
– Child care
– Preventive care – immunization – Clean water
– Adequate nutrition
– Medial treatment, etc.
Immunization
A process that stimulates the body’s immune system to defend against attack by a particular contagious disease (immunization acquired either naturally, by having the disease or though vaccination)
immunization successes
– Smallpox
– Polio
– Measles
problem with immunization
parents are concern about side effects of vaccinations
Sudden Infant Death Syndrome (SIDS)
- die unexpectedly in their sleep
- No apparent cause of death
- 1990 in the U.S., 5000 babies died of SIDS, 1 in 800
What connection is there between breast feeding and sleep?
Breast fed babies don’t get as deep of a sleep
What affects sids? How?
Culture, co sleeping and such
Colostrum
a thick, high-calorie fluid secreted by the woman’s breast at the birth of a child - antibodies.
About _ days later the breast begins to produce milk
3
Breast fed babies are __ likely to get sick
less
protein-calorie malnutrition
a condition in which a person does not consume sufficient food of any kind
What can protein-calorie malnutrition result in?
everal illnesses, severe weight loss, and sometimes death
Head-Sparing
brain continues to develop even though body stops because of malnutrition
to measure a child’s nutritional status, we…
compare weight and height with the
“norms”
Percentile
point on a ranking scale 1-99
Under-nutrition contributes to nearly half of all deaths in children under 5 and is widespread in ___ and ___
Asia and Africa
Malnutrition Infants suffer in 3 main ways:
1) Brain does not have enough nutrition to normally develop
2) They have no body reserves to protect them against disease. Child disease therefore will be much more lethal
3) Two serious conditions may result:
a) Marasmus
b) Kwashiorkor
Marasmus
severe protein malnutrition, which growth stops,
tissues waste, eventual death
Kwashiorkor
protein deficiency results in face, legs and abdominal bloating – child more vulnerable to disease
Beginning early in the first year, sensitive parenting is associated with:
improved child socio-emotional development, mental health, and language
Neglect and Brain Development
• Limited exposure to language, touch or social interactions
• Emotional or cognitive neglect
• Early life stress
• Structural Changes
–> Lack of brain growth beyond effects of poor nutrition
–> Neuronal death beyond pruning
–> Decreased dentritic arborization, number of spines and reduced synapses, reduced white mater.
How would a neuron damaged by toxic stress look like? Where does this take place?
It has fewer connections
Prefrontal cortex and hippocampus
Smell and taste at present at ___ and right away begin ____ to the world.
Birth, adapting
Hearing develops in the _____ trimester of pregnancy
last
Do babies have mature or immature vision at birth?
Immature, legally blind
When does a baby get binocular vision?
2-4 months
Myelin
Myelin is a fatty white substance that surrounds the axon of some nerve cells, forming an insulating layer, increasing the speed at which impulses are conducted.
Concepts and categories develop in infant’s brains by _ months or earlier.
6
