chapter 11 Flashcards
Early Childhood (1 - 6 years) growth
Structural changes: • A period of moderate growth - ossification of skeleton continues - muscle growth - organ growth - tooth formation - delayed reproductive organ growth Motor development: • Rapid development of motor skills
Late Childhood (6 - 12 years) growth
Structural changes:
• Physical growth slows in preparation for the adolescent growth spurt
Motor development:
• Consolidation of motor skills.
• By 12 years, 80-90% proficient in complex skills like jumping, hitting, throwing and catching (given the right environment)
Quiescence
Just prior to the start of the adolescent growth spurt:
• About 12 years for boys
• About 10 years for girls
Growth is at a minimum.
Postnatal Posture development
Remarkably low muscle power ~ 2 months
head cannot balance
trunk cannot be supported against gravity
lack of neural control of postural responses
adaptation to extrauterine environment takes ~ 2 months to overcome
Locomotor Development
Neonatal stepping response rolls from side to back ~ 1 month rolls supine to prone ~ 6 months creeping/crawling ~ 8+ months cruising with support ~ 9 months upright locomotion ~ 11.5 months
Developmental and Adult brain:
plasticity is different
Dramatic changes that occur during development do not recur in the adult brain
– structural growth & retraction more
restricted
– cell death & dendritic arborization continue
t/out life but not to same extent
– plasticity in adult brain (i.e., learning) is
related to synaptic strength
Shared mechanisms between
development and adult
learning
Repetitive stimulation and activity in neural pathways are important (critical experience)
synaptic activity enhances pathways - fine tuning,
pruning of connections, cell survival
the adult brain retains some plasticity - NOT to the
same degree as developing child (hence MJ’s
problem in changing sport?)
Adolescence
The growth period encompassing change from a child to an adult (including both physical & psychological/
behavioural development).
Puberty
Refers to a time when sexual reproduction is possible
(ie. The attainment of sexual competence.)
• Males - the development of sperm
• Females - the age of menarche / ovulation
REPRODUCTIVE DEVELOPMENT
Male Development: • Growth of penis, testes & scrotum • Pubic, axillary &facial hair Female Development: • Breast bud vagina & uterus • Menarche - generally after PHV • Menarche often occurs without an ovum being shed • Pubic & axillary hair
Maturity Assessment
- Chronological Age
- Pubescent Age
- Skeletal Age
- Dental Age
- Morphological Age
GROWTH OF SHORT BONES
Growth of the cartilage model (chondrogenesis)
precedes the formation of short bones in an indirect ossification process.
(Dental Age Assessment
A radiograph of the upper and lower jaws reveals:
• the formation of teeth within the gum;
• the eruption of teeth from the gum; and
• the shedding of teeth
(Problems with all Developmental Age Strategies)
There is much we do not fully understand about adolescent
development. These assessment tools act as a guide to pinpointing the current maturity status only, and there is no guarantee they will continue to follow this trend. Hormone secretions tend to speed up then slow down, causing:
• for some it may take 5 years to pass from PA stage 1-5
• for others this may take only 2 years
• some early maturers may slow down and not complete
adolescence for a long time, and vice versa.
Cellular changes with ageing
- General
• Nervous System
