Chapter 5 Flashcards
(81 cards)
1
Q
cephalocaudal principle
A
- toddlers have a disproportionately large head and trunk, making them top-heavy compared with older children
2
Q
Muscle growth in children
A
- Virtually all of the body’s muscle fibres are present at birth
- During childhood, muscles become longer and thicker as individual fibres fuse together
- This process accelerates during adolescence, particularly for boys
3
Q
Fat growth in children
A
- layer of fat first appears under the skin near the end of the fetal period
- fat continues to accumulate rapidly during the first year after birth (“baby fat”)
- during the preschool years, children become leaner
- in the early elementary school years they begin to acquire more fat again (gradually)
- increases more rapidly in adolescence (more in girls than boys)
4
Q
Bone growth in children
A
- bone begins to form during prenatal development (starts as cartilage)
- during embryonic period, middle of tissue turns to bone
- shortly before birth, ends of cartilage structures (epiphyses) turn to bone
- working from middle, cartilage turns to bone until middle reaches epiphyses
5
Q
Secular growth trends
A
- changes in physical development from one generation to the next that are related to environmental factors
- today we are taller and heavier than previous generations
6
Q
Three factors of physical growth
A
- heredity
- hormones
- nutrition
7
Q
Heredity (mechanisms of physical growth)
A
- correlation between heights of identical twins is higher than fraternal twins
- heredity plays a role in determining adult height and rate of growth
- parents contribute equally to height
8
Q
Hormones (mechanisms of physical growth)
A
- pituitary gland secretes growth hormone (GH) a few times a day (usually during sleep but sometimes after exercise)
- GH travels from pituitary to liver and triggers release of hormone somatomedin which causes muscles and bone to grow
- without enough GH, child develops dwarfism (can be treated w GH injections)
- thyroxine (released by thyroid in back of neck) is essential for proper dev. of nerve cells and cell function throughout the body
- deficiency of thyroxine = cognitive delay or retard physical growth by making pituitary gland ineffective
- too much thyroxine linked to anxiety-related problems
- alcohol consumption in pregnancy = decreased maternal thyroid function =? predisposition of offspring to cognitive delays
9
Q
Nutrition (mechanisms of physical growth)
A
- introduce only one new food at a time so you can monitor for reactions
- bottle feeding is fine if it is clean but infants can develop allergies from it
- picky eating starts around age 2 when children need less food; might be adaptive bc eating familiar foods protects toddlers from potential harm
10
Q
Energy use in 2 month olds
A
- about 40% dedicated to growth
- most of remaining energy fuels basicbody function
- why babies must consume an enormous number of calories in relation to body weight
11
Q
Foods that can be introduced to a 6-9 month old
A
- rice cereal, then other cereals
- strained vegetables, then strained fruits
12
Q
Foods that can be introduced to a 7-9 month old
A
- protein foods (cheese, yogurt, cooked beans, pureed meats)
13
Q
Foods that can be introduced to a 9-10 month old
A
- finely chopped meat, toast, crackers
14
Q
Foods that can be introduced to a 10-12 month old
A
- egg yolk
15
Q
3 challenges to healthy growth
A
- malnutrition
- disease
- accidents
16
Q
Malnutrition (challenges to healthy growth)
A
- malnutrition mostly occurs in developing countries but is also common in industrialized countries
- especially damaging during infancy bc growth is so rapid
- children with history of infant malnutrition grow typically later on but score lower on intelligence tests and have difficulty focusing at school
- to prevent malnutrition you need a combination of food availability, nutrition education, and behavioural change
17
Q
Diseases (challenges to healthy growth)
A
- leading causes for mortality in young children are preterm birth complications, pneumonia, birth asphyxia, diarrhea, and malaria
- 45% of all childhood deaths related to malnutrition
- asthma diagnosis increasing in Canada (higher rates in Atlantic Canada)
- immunization and parent education are important
- WHO and UNICEF created Integrated Management of Childhood Illness (IMCI) to improve children’s health worldwide
18
Q
Accidents (challenges to healthy growth)
A
- after first year of life children are most likely to die from accidents (often motor vehicle accidents)
- many children also die around pools, unable to recognize hazards
19
Q
Components of a neuron
A
dendrite–axon–soma–terminal buttons
20
Q
Organization of the mature brain
A
- about 80 billion neurons and 80 billion glia (support cells)
- wrinkled surface of brain = cerebral cortex (10 billion neurons)
- cortex consists of right and left cerebral hemispheres linked by corpus callosum
- personality and ability to carry out plans mostly linked to frontal cortex
- left hemisphere=language, reasoning, computing
- right hemisphere=artistic+musical abilities, perception of spatial relationships, and recognizing faces and emotions
21
Q
Adrenaline
A
- fight or flight
- produced in stressful situations
- increases heart rate + blood flow, heightens awareness
22
Q
GABA
A
- calming
- calms firing nerves in CNS
- high levels improve focus, low levels cause anxiety
- contributes to motor control and vision
23
Q
Noradrenaline/Norepinephrine
A
- concentration
- contracts blood vessels and increases blood flow
- affects attention and responding actions in the brain
24
Q
Acetylcholine
A
- learning
- involved in thought, learning, and memory
- activates muscle action in the body
- associated w attention and awakening
25
Dopamine
- pleasure
- feelings of pleasure, addiction, movement and motivation
- we repeat behaviours that lead to dopamine release
26
Glutamate
- memory
- most common neurotransmitter
- involved in learning and memory
- regulates development and creation of nerve contacts
27
Serotonin
- mood
- contributes to well-being and happiness
- helps sleep cycle and digestive system regulation
- affected by exercise and light exposure
28
Endorphins
- euphoria
- released during exercise, excitement, and sex
- produces well-being and euphoria, reduces pain
29
Frontal lobe key roles
- motor control (premotor cortex)
- problem solving (prefrontal area)
- speech production (Broca's area)
30
Temporal lobe key roles
- auditory processing
- language comprehension (Wernicke's area)
- memory/information retrieval
31
Brainstem key role
- involuntary responses
32
Cerebellum key role
- balance and coordination
33
Occipital lobe key roles
- sight (visual cortex)
| - visual reception and visual interpretation
34
Parietal lobe key roles
- touch perception (somatosensory cortex)
| - body orientation and sensory discrimination
35
Electroencephalogram (EEG)
- electrodes record electrical brain activity in brain's outer layers
- great temporal resolution, bad spatial resolution
36
Event-related potentials
- uses EEG
- brain wave amplitude measured in response to particular stimuli
- enables identification of general regions of stimulus-induced activity
37
Functional magnetic resonance imaging (fMRI)
- tunnel-shaped apparatus creates magnetic field
- scanner magnetically detects increased blood flow and oxygen metabolism in areas of the brain
- good spatial resolution, bad temporal resolution
38
Positron emission tomography (PET)
- functional imaging technique that uses radioactive tracer to measure changes in metabolic processes, and in other physiological activities
- okay spatial resolution, bad temporal resolution
39
Near-infrared spectroscopy (NIRS)
- infrared light beamed into brain; absorption by areas of cerebral cortex varies with changes in blood flow and oxygen metabolism as individual processes stimuli
- produces computerized moving picture of active areas in cerebral cortex
- appropriate for infants and young children bc they can move a bit
40
When does nervous system development start?
- around 3rd week of embryonic development
- neuron production starts around 10 weeks after conception
- all 6 layers of neurons are in place about 7 months after conception
41
Basic steps of early neural development
- layer of ectoderm thickens to form neural plate
- neural plate folds inwards to form neural groove
- after 4th week neural folds are completely fused and form neural tube
- bulges and bends appear in neural tube (3 bulges=primary vesicles)
42
3 primary vesicles of neural tube
- prosencephalon (will form cerebrum -- divides into telencephalon and diencephalon)
- mesencephalon (will form midbrain)
- rhombencephalon (will form rest of brain stem and cerebellum -- divides into metencephalon and myelincephalon)
- end of neural tube forms spinal cord
43
What part of the brain develops fastest
telencephalon
44
What part of the brain develops last
prefrontal cortex (higher cognitive function)
45
Prefrontal cortex
- responsible for thought
- consciousness
- inhibition of impulses (starts regulating inappropriate responding around 1 year)
- memory, reasoning, planning, and problem-solving strategies
- rapid growth in preschool and school years, and in adolescence
- little activity in babies les than 11 weeks
- activity reaches adult ish levels at 7-8 months
46
Right cerebral hemisphere
- spatial abilities
- negative emotion
- holistic, integrative processing
47
Left cerebral hemisphere
- verbal abilities
- positive emotion
- sequential, analytic processing
48
Left frontal cortex
regulates emotions stemming from tendency to approach
49
Right frontal cortex
regulates emotions stemming from avoidance
50
Fine-motor skills
- self-help, dressing, eating
- drawing and printing
- things that will be a part of every day routine
51
Gross-motor skills
- walking, running, jumping, catching, swinging, riding
- balance, speed, endurance
- things not involving precise fine movement
- develops through play
52
Sequence of fine-motor skill development
- newborn: prereaching
- 3-4 months: ulnar grasp (grab w whole hands or both hands)
- 4-5 months: transfering object from hand to hand
- 9 months: pincer grasp
53
Babinski reflex
- fans out toes and twists foot in
- when sole of foot stroked
- disappears at nine months
54
Grasping/Palmer reflex
- grasps when palms touched
| - weakens at 3 months, disappears at a year
55
Moro relfex
- startles; throws out arms and legs and then pulls them toward body
- reaction to sudden move or loud noise
- disappears at 3-4 months
56
Rooting reflex
- when cheek stroked or side of mouth touched
- turns toward source, opens mouth and sucks
- disappears at 3-4 months
57
Stepping reflex
- when infant held upright with feet touching ground
- moves feet as if to walk
- disappears at 3-4 months
58
Sucking reflex
- sucks when mouth touched by object
| - disappears at 3-4 months
59
Swimming relfex
- when placed face down in water
- makes coordinated swimming movements
- disappears at 6-7 months
60
Tonic neck reflex
- when placed on back
- makes fists and turns head to the right
- disappears at two months
61
Age a child can lift chin up
1 month
62
Age a child can lift chest up
2 months
63
Age a child can reach and miss
3 months
64
Age a child can sit with support
4 months
65
Age a child can sit on a lap and grasp object
5 months
66
Age a child can sit alone
6-7 months
67
Age a child can stand with help
7-8 months
68
Age a child can crawl
7-8 months
69
Age a child can pull to stand by furniture
8 months
70
Age a child can stand alone
11 months
71
Age a child can walk alone
12 months
72
Smell in infants
- newborns have keen sense of smell
| - mothers can pass on odor preferences
73
Taste in infants
- infants readily differentiate salty, sour, bitter, and sweet tastes
- prefer to drink mothers milk after she has eaten something sweet
74
Hearing in infants
- hear well but not as well as adults
- best for sounds w pitches in range of human speech
- demonstrate early sensitivity to music
75
Sight in infants
- by 3 months all 3 kinds of cones work and infants see in full colour
- acuity improves rapidly from 1 month to 1 year
- by 3 months infants recognize faces (look more at features)
76
Retinal disparity
- binoccular depth cue
- used as depth cue by 4-6 months
- greater disparity=closer object
77
Monoccular depth cues
- texture gradient (closer objects more textured)
- interposition (near objects partially obscure more distant ones)
- linear perspective (parallel lines come together in distance)
- relative size (nearby objects are closer than far away objects)
78
Visual cliff experiment
- babies as young as 1 1/2 months slow heartbeat when placed on deep side of platform with visual cliff
- heart rate often goes down when we notice something interesting
- shows babies notice deep side is different
79
Synaptic pruning
- starts after 1st birthday
| - synapses begin to disappear as the brain weeds out unnecessary or underutilized connections between neurons
80
Dynamic systems theory
theory that upholds that motor development involves many distinct skills, organized and reorganized over time to meet demands of specific tasks
81
Handedness
- babies start to show preference for one hand around 13 months
- strengthens with age and is well-established by the time they enter kindergarten
- heredity plays a role, but also experience
