3.1, 3.2 - physical development across the lifespan

Stability perspective

Traits remain consistent over time

Change perspective

People change & evolve over time

Continuity / continuous view

Elements of development occur in a steady progress

Stages view

Developmental changes occur in clear, abrupt stages

Prenatal

Time between birth & conception

Placenta

Life-providing organ

Teratogens

Harmful agents (chemicals or viruses)

Fetal alcohol syndrome

Alcohol leaves chemical markers on DNA, turns genes on or off (epigenetic effect)

Rooting reflex

Turn toward touching around the mouth

Sucking reflex

Allows for tonguing, swallowing, breathing to help drink milk

Grasping reflex

Clinging response to touch on the palm (prepares for voluntary grasping)

Tonic neck reflex / fencing posture

Helps develop muscle tone, hand-eye coordination, balance

Maturation

Biological growth processes

Myelination

Nerve fibres begin to be surrounded by myelin - allows faster neural connections

Adolescence

Life between childhood & adulthood

Puberty

Beginning of adolescence. Time we mature sexually

Selective pruning of neurons

Unused neuronal connections are lost to make paths more efficient

Menarche

First menstrual period in females

Spermarche

Beginning of sperm production in males

Unisex chromosomes

Same for males & females

Gender dysphoria

Unease of a mismatch between their biological sex and their gender identity

Menopause

End of female menstrual cycle ~50

Apoptosis

When a telomere is at a critical length & dies.

Primary sex characteristics

Reproductive organs ( ovaries & testes ) and external genitalia

Secondary sex characteristics

Nonreproductive traits ( breasts, hips, pubic hair, facial hair, deep voice )