Midterm 1 Flashcards
Development Definition
change in the individuals level of functioning
quantitative change
change in number or amount
- measurable change
qualitative change
change in structure or organization as marked by the emergence of a new behaviour
heredity
set qualities fixed at birth: characteristics and traits
can heredity be modified?, How?
yes, by environment
maturation
biological changes, height, weight, etc
stability
state in which characteristics and abilities stay the same or function similarly across lifespan
aging
process occurring with passage of time leading to loss of function
behaviour
physical observable actions
affect
emotional experience
cognition
thinking abilities
motor development
study of change in movement behaviour
motor learning
relatively permanent gains in motor skill capability (from practice or experience) - long term change
motor control
neural, physical, and behavioural aspects of movement
2 Sequences of growth
- cephalocaudal development
- proximodistal development
cephalocaudal development
growing proceeds from head to feet
proximodistal development
growing proceeds from centre of body to periphery
- trunk to shoulders to hands
genotype
blueprint of information in DNA
phenotype
observable traits
twins studies determined
genes matter for motor skills
- influence of genes declines over time (in comparison to environmental influenes
CNS
spinal cord and brain
- take info from environment
PNS
nerve fibers that connect the body to CNS
- autonomic system
- controls voluntary movements like walking
Brainstem
- reflexes
- breathing
- heartbeat and rhythm
medulla
- in brainstem
- sensory signals from SC and motor signals from brain
- respiration, BP, HR
Pons
- in brain stem
- coordination and posture
- involuntary influences
midbrain
- in brainstem
- reflex movements from visual and auditory stimulation
thalamus
- in brainstem
- important integration center
cerebral cortex contains
- frontal lobe
- parietal lobe
- occipital lobe
- temporal lobe
motor cortex contains
- primary motor cortex
- premotor cortex
- supplementary motor area
- posterior parietal cortex
primary motor cortex
- actual execution of movements
- speed and force of actions
premotor cortex
- working memory
- plan and guide movement
supplementary motor area
- preparation of movement
posterior parietal cortex
- planned movements, spatial reasoning, attention
basal ganglia
integrate sensory motor centres
- unconscious behaviour
- planning and coordinating movements
- fundamental body movements
cerebellum
responsible for balance and the timing of movements
nerve fiber types
- afferent fibers
- efferent fibers
- cranial nerves
- spinal nerves
afferent fibers:
transmit sensory info to SC and brain
efferent fibers
transmit motor impulses from CNS to periphery
cranial nerves
transmit info with the brain
spinal nerves
transmit info within SC
neuron
Specialized cells that send and receive signals
3 types of neurons
- sensory neurons: signals to SC, brain, afferent
- motor neurons: signals from CNS to muscles
- interneurons: info through CNS
nature contributes to
pre-wiring
environment
fine tunes connections
brain development sequence of events
- cell proliferation
- migration: move where needed
- integration and differentitation
- myelination
- cell death
when does the brain growth spurt/ critical period of neural development happen
3rd trimester to 4th year of life
what happens with the development of dendrites
thick ones develop prenatally and are responsible for brain growth from birth to age 2
synapotgenesis
building synapses
- transmission between axon of neuron and dendrite of another neuron
where does the most neuron growth happen after birth
hippocampus
- neurogenesis: influenced by PA!
roles of myelination
- visual pathways
- touch
- motor control
- higher brain functions
- memory
when does memory develop
well into the 30s
when does touch develop until
2 years old
link of myelination to what types of movement
neurogenic behaviours : neural connection to muscle
reflexes : connections of sensory input and motor response
voluntary movement control
when does cell pruning and death happen around, and why does it happen
10 years of age
- use it or lose it
how much neutrons may the brain lose in pruning and cell death
40-75% of neutrons they originally made
windows of opportunity for 1. gross motor skills 2. fine motor skills 3. un\used connections
- prenatal to age 5
- improves till age 9
- fade away around age 10
brain growth sequence
- midbrain: reflexes, automatic processes
- cerebrum: complex thinking and functioning
- cerebellum: coordination and balance
bone structure compenents
- extracellular matrix
organic (collagen) and inorganic components
bone cells
what are the types of bone cells
osteocytes
osteoblasts
osteoclasts
osteogenic cells
inorganic component allows for
hardness and structure
osteoclasts job
carve for calcium, protein, other ions for bone respiration
bone remodelling is a
lifelong process
compact bone
80% of bone mass
(cortical)
- dense outer region
- allows bone to resist bending and torsion
spongy bone
20% of bone mass (trabecular)
deep to compact bone, mesh like trabeculae
allows for bone to resist forces in many directions
bone marrow
found within medullary cavity and within spongy bone
- red marrow
- yellow marrow
red marrow
site of hematopoiesis (formation of blood cellular components)
- cranium, vertebral body, ribs, sternum, allium, proximal epiphyses of humerus and femur
yellow marrow
found in long bones of adults
- adipose tissue
bone remodelling: formation & resorption
- balanced activity of osteoclasts and osteoblasts
modulated by hormones
modulated by physical stress - use it or lose it policy
what hormones modulate bone remodelling
- parathyroid hormones
- calcitonin
- estrogen
-testosterone - growth hromone
- cortisol
peak bone density determined by
- genetics (60-80%)
- hormones (estrogen and testosterone)
- physical activity
- nutrition (calcium, vitamind D, protein)
predictors of bone loss
- hormone changes
- estrogen, testosterone
- physical inactivity
- chronic inflammation
- inadequate nutrient intake or absorption
- smoking
- high alcohol intake
when is peak bone density in females
around 15 years old
- stays ok till menopause (around 52). then rapid decline
when is peak bone density in males
16-22 years old
osteoporosis
loss of bone mass and density, loss of bony matrix and mineralization
- cortical bone becomes porous and thin
- trabecular bone loss and thinning
Bone mass
amount of bone tissue in the skeleton
bone density
mineral mass per unit of volume of bone
signs of osteoporosis
shrinking, losing height, loose geometry
two forms of osteoporosis
- primary : age related: increased risk among older females
- secondary: due to another disorder or issue
- conditions associated with bone loss
- prolonged use of drugs
- alcoholism
risk factors for osteoporosis
- genetics
- age
- sex
- menopause (estrogen deficiency)
- sedentary life
- nutrition deficits or malabsorption
- cigarette smoking
- prolonged glutoccorticoid use
what is the ratio of osteoporosis risk for females vs males
females= 1:3
males= 1:5
how does low estrogen cause osteoporosis and resorption
low estrogen stimulates increased osteoclasts activity, ramping up the RANK-L pathway and pro inflammatory cytokines
DIRECT IMPACT: increased osteoclast, decreased osteoblasts activity
INDIRECT IMPACT: increased cytokine activity (stimulates OC), increased OC activity via RANK receptor pathway
how does chronic inflammation effect peak bone density level
- pro inflammatory cytokines increase OC activity
age related decline causes
decline i
when does plasticity happen
- durning normal development
- new skills
- after injury healing damaged areas
what is plasticity
brain and body ability to adapt to change and reorganize in response to experiences and environmental stimuli
when does the brain reach nearly 90% of its adult size
age 3
when does the brain reach its full size
age 6
what is the growth sequence of brain
1.midbrain first
2. cerebrum second
3. cerebellum last
neuron loss physiology
- dendrites shrink
- axons loose density
- psychomotor slowing
- decline in valance
- cerebellum loss of cells
- slower nerve signals
physical anthropology
provides information and scientific procedures related to the study of biological growth and development
anthropometry
branch of science concerned with biological growth and body measurement
what happens in the germinal period- prenatal development
cell division and implantation
what happens in the embryonic period- prenatal development
foundation for Motor skills and cognitive functions
- teratogen exposure may lead to congenital disorders
what happens during the fetal period- prenatal development
growth and maturation of organs and tissue
low birth weight/pre-maturity effects
(less than 5lbs)
- caused by premature birth or fetal growth restriction
*not automatically bad, can catch up
but can have health risks; especially less than 1lb
- motor dysfunction and delay risk
what are hormones
chemical messengers that tell the body what to do and responsible for major growth and development in puberty
what is involved in hormonal control
- hypothalamus : body control centre
- pituitary gland : master gland
supporting glands:
- gonads
- thyroid gland
- adrenal gland
hormonal sequence
- hypothalamus
- pituitary gland
- thyroid, gonads, adrenal : produce growth hormones
- produce thyroxine, testosterone and estrogen, and androgens
testosterone
- levels increase 10x in puberty for males, 2x for females
- builds muscle
- strengthens bones
- closes growth plates
estrogen
- increases 10x in puberty for females, 2x in males
- growth spurt
- bone development
- tells body to store fat
- closes growth plates earlier than boys
when is growth hormone therapy prescribed
- to children 2-2.5 standard deviations below mean height for age (SGA)
why is assessing brain growth important
we can spot hydrocephalus (fluid build up in brain)
when does height reach a steady state
Men: 18-30
Women: 16.5-30
when does height decline with age
after our 30s
what physical changes happen to bones during growth
- bones grow longer, thicker
- long bones go through modeling respiration
(extra bone tissue breaks down to maintain shape> middle stays slim and ends grow bigger - short bones develop out of the core bone in centre and enlarge
difference between female and male bone growth
- females 20% advance skeletal maturity at birth
- greater size in males bones post puberty
adulthood : body weight change
20x weight than at birth
- declines later in life due to bone and muscle tissue loss
what does a DXA scan measure
- body fat
- muscle and bone density
hyperplasia body fat cells growth
rapid growth before birth and into first year of life
hypertrophy of body fat cells
dependent on food intake, can lead to hypertrophy in tandem
advanced aging effects
- heigh decreases with age
- weight increases steadily from 20s-60 years old
- weight declines after 60 years old
fat storage: - males store fat in belly
- females store fat in hips, thighs, breasts
- lean body mass decreases with age due to bone and muscle mass decline
how much of fat storage patterns do genetics effect
patterns in storage inherited by 50% genetic
maturity can be estimated by
- morphological age
- dental age
- sexual age
- Skeletal age
sexual age determined by
- sex characteristics
- menstruation in females
skeletal age determined by
- cartilage change over time (ossification)
maturity variations are measured by
comparing skeletal age and chronological age
- 20% difference from average or 1-3years classifies an early/late maturer
secular trends
growth and maturity rates that change throughout generations
- better living conditions
postnatal development influences
- nutrition (balanced< for repair of body tissues)
- physical activity (no effect on body physique but can contribute to positive development)
cardiorespiratory structures to have memorized
- heart
- air flow
heart growth
- grows rapidly (big growth spurt in later years)
heart grows in proportion to
heart blood volume
heart growth sex differences
relatively the same until puberty
- at puberty *male heart 15% larger then female
lung growth - prenatal development
- lung buds
- bronchial
- sensory/motor and nerves
- capillaries (at 20 weeks)
- alveolar-capillary interface: gas exchange
lung growth- postnatal development
-at birth 20 million alveoli present
- rapid growth after birth
year 1: 3x lung capacity
year 8: same alveoli as adult
after age 8: alveoli growth bigger : chest wall grows
