2F03 - UNIT 1

Growth

* most dominant biological activity for the first 2 decades of life
* change in size
* outcome of 3 underlying cellular processes

Cellular Processes of Growth (3)

* hyperplasia
* hypertrophy
* accretion

Hyperplasia

* increased cell number
* intracellular
* can know # of neurons mid pregnancy
* can know # of muscle fibres post natally

Hypertrophy

* increased cell size
* intracellular
* increased cell units within cell protein + substrates

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neuron: 2nd half of pregnancy → post natal life

muscle: occurs during growth + resistance training

Accretion

* increased intercellular substances
* intercellular
* gradual accumulation
* organic/inorganic material that binds/aggregates cells in network

Maturation

* process in organs, organ systems, enzymes, chemical composition and functions
* timing & tempo

Maturity

* state → varies with biological system

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sexual: fully functional reproductive capacity

skeletal: fully ossified adult skeleton

Biological Development

process of differentiation and specialization

Behavioural Development

development of competence of interrelated domains as a child adjusts

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* involves acquisition and refinement of societal expectations

Physical Activity

any body movement by skeletal muscles resulting in an increase in resting energy expenditure

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e.g. house chores, sport, PE class

Physical Fitness

varying adaptive states; varies with growth, maturity, habits, life-style

Isometric Growth

equal growth in part of an organism in relation to its whole

Allometric Growth

unequal growth in part of an organism in relation to its whole

Relative Change of Head

2 month fetus: 50% of length

birth: 45% of length

adult: 12.5% of length

Relative Change of Legs

2 month fetus: 15% of length

birth: 37% of length

adult: 50% of length

Scammon’s Curve

* uses tissue & organ weights at each age to characterize growth
* general, neural, genital, lymphoid

Four Phases of Growth

1. rapid gain in infancy/early childhood
2. steady gain during mid-childhood
3. rapid gain during adolescent spurt
4. slow increase until growth ceases

Chronological Age

* time framework
* can be viewed at single/many points

Age Groups

* infancy
* perinatal
* neonatal
* post natal
* childhood
* early
* middle
* adolescence

Reasons to Study Growth and Development

* evaluate status
* evaluate progress
* predict future state
* follow characteristics overtime
* generate norms for reference

Pros and Cons of Child Development and Sport

pros

* regular physical activity
* stronger heart + endurance
* social skills

cons

* falling behind in other skills
* injuries
* stresses of burnout/competition

Newell’s Theory of Constraints

structure/function, environment can constrain motor development